Analytical and Applied Chemistry: the challenges and opportunities for growth in the 21st century

A topical collection in Analytica (ISSN 2673-4532).

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Editors


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Guest Editor
Department of Pharmacy, University “G. d\'Annunzio” of Chieti and Pescara, Chieti, Italy
Interests: innovative (micro)extraction procedures; hyphenated instrument configurations; bioactive compounds; characterization; fingerprints; method validation; HPLC; mass spectrometry; biological matrices; chromatography; analytical chemistry; sample preparation; green analytical methodologies
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Laboratory of Analytical Chemistry, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Interests: analytical chemistry; sample preparation; chromatography; HPLC; method validation; method development; separation science; food analysis; bioanalysis; environmental analysis; green analytical chemistry; sorptive extraction; microextraction techniques
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department for Life Quality Studies, Alma Mater Studiorum—Università di Bologna, 47921 Rimini, Italy
Interests: drug analysis; toxicological analysis; HPLC; capillary electrophoresis; method development; microsampling; sample preparation; antioxidants; biological matrices
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Leibniz-Institute of Photonic Technology, 07745 Jena, Germany
Interests: chemometrics; image analysis; signal treatment; machine learning

Topical Collection Information

For this first Special Issue/topical collection, we decided to use the title "Analytical and Applied Chemistry: Challenges and Opportunities for Growth in the 21st Century", as never before has analytical chemistry, especially applied analytical chemistry, seen such a growing pre-eminence in all fields. Nowadays, the analytical approach is fundamental from production to quality control, from food to anti-adulteration analyses, from doping to forensic analyses, from environmental analyses to those in the clinical/biological field.

In this Special Issue, we want to collect reviews and research papers that report on the state of the art of the various "sections" in which the journal is organized, while trying to offer ideas and opportunities for reflection on the possible challenges that will soon await those who work in the analytical and applied analytical chemistry field. In particular, we also want to highlight and try to provide possible elements for discussion and ideas for research/collaboration for the huge opportunities that will open up in the near future and the growth prospects of the international analytical community.

The goal is to put in contact and create a "core" of experts who can act as a reference with their ideas and opinions in order to avoid the "dispersion" of forces and bring analytical chemistry and applied analytical chemistry at the center of the international scientific scene. Our additional goal is to increase the role of the analytical field as a reference against all that competes with qualitative–quantitative analysis in a complex matrix through various instrumental techniques, trying to increase the opportunities for intervention and growth in this branch of chemistry. 

Prof. Dr. Victoria Samanidou
Prof. Dr. Marcello Locatelli
Dr. Roberto Mandrioli
Dr. Thomas W. Bocklitz
Guest Editors

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Published Papers (48 papers)

2024

Jump to: 2023, 2022, 2021, 2020

17 pages, 2647 KiB  
Article
A Metabolomics Study by 1H HRMAS NMR: From Sheep Milk to a Pressed-Curd Cheese: A Proof of Concept
by David Castejón, José Segura, Karen Paola Cruz-Díaz, Víctor Remiro, María Encarnación Fernández-Valle, María Dolores Romero de Ávila, Palmira Villa and María Isabel Cambero
Analytica 2024, 5(2), 170-186; https://doi.org/10.3390/analytica5020011 - 13 Apr 2024
Viewed by 429
Abstract
For the first time, High-Resolution Magic Angle Nuclear Magnetic Resonance spectroscopy (NMR-HRMAS) was applied to directly identify specific metabolites from a Spanish raw ewe’s milk and enzymatic coagulation pressed-curd cheese (Protected Geographical Indication: Castellano) manufactured by two procedures (traditional/artisanal vs. industrial) and [...] Read more.
For the first time, High-Resolution Magic Angle Nuclear Magnetic Resonance spectroscopy (NMR-HRMAS) was applied to directly identify specific metabolites from a Spanish raw ewe’s milk and enzymatic coagulation pressed-curd cheese (Protected Geographical Indication: Castellano) manufactured by two procedures (traditional/artisanal vs. industrial) and including the ewe’s raw milk. The NMR parameters were optimized to study the complex matrixes of this type of cheese. In addition, conventional overcrowded 1H-NMR-HRMAS spectra were selectively simplified by a Carr–Purcell–Meiboom–Gill (CPMG) sequence or a stimulated echo pulse sequence by bipolar gradients (DIFF), thus modulating spin–spin relaxation times and diffusion of molecular components, respectively. 1H-NMR-HRMAS spectroscopy displayed important information about cheese metabolites, which can be associated with different manufacturing processes (industrial vs. traditional) and ripening times (from 2 to 90 days). These results support that this spectroscopy is a useful technique to monitor the ripening process, from raw milk to commercial ripened cheese, using a minimum intact sample, implying the absence of time-consuming sample pretreatments. Full article
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17 pages, 3782 KiB  
Article
Headspace-Selected Ion Flow Tube Mass Spectrometry Workflows for Rapid Screening and Quantitation of Hazardous Volatile Impurities in Personal Care Products
by Mark J. Perkins, Colin J. Hastie and Vaughan S. Langford
Analytica 2024, 5(2), 153-169; https://doi.org/10.3390/analytica5020010 - 02 Apr 2024
Viewed by 344
Abstract
Personal care products (PCPs) are intended for regular application by consumers and therefore assuring the safety of these products is very important. Recently, benzene contamination has been highlighted in certain PCPs. The present study applies selected ion flow tube mass spectrometry (SIFT-MS) to [...] Read more.
Personal care products (PCPs) are intended for regular application by consumers and therefore assuring the safety of these products is very important. Recently, benzene contamination has been highlighted in certain PCPs. The present study applies selected ion flow tube mass spectrometry (SIFT-MS) to a simultaneous headspace analysis of benzene, 1,4-dioxane, and formaldehyde—all known or suspected carcinogens—in nine haircare products with supporting qualitative analysis by gas chromatography–mass spectrometry (GC-MS). Headspace-SIFT-MS method development is compatible with the method of standard additions, which is necessary for the quantitation of volatile impurities in these complex emulsions. Benzene was quantified above the low-ng g−1 limit of quantitation (LOQ) in three products, dioxane above the sub-μg g−1 LOQ in all products, and formaldehyde above the low-μg g−1 LOQ in two products, providing a quantitative analysis at concentrations relevant to consumer safety. This study facilitated the development of generic workflows for SIFT-MS method development and application in routine analysis of PCPs. The assessment of workflows for SIFT-MS compared to a conventional GC-MS analysis suggests that 8- to 30-fold throughput enhancements may be possible for quantitative and screening analysis using SIFT-MS. Full article
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14 pages, 473 KiB  
Article
Analytical Compatibility between Various Techniques for Determining Dissolved Manganese in Produced Water
by Gabriela Knippelberg Bifano Manea, Vanusa Bueno Freire, Rainerio Escalfoni Junior and Elcio Cruz de Oliveira
Analytica 2024, 5(1), 139-152; https://doi.org/10.3390/analytica5010009 - 15 Mar 2024
Viewed by 638
Abstract
Petroleum-produced water is the primary effluent generated during the oil extraction process, presenting high flow rates, and containing a series of chemical components that are harmful to the environment, such as dissolved manganese. The proof of metrological compatibility between laboratories and different test [...] Read more.
Petroleum-produced water is the primary effluent generated during the oil extraction process, presenting high flow rates, and containing a series of chemical components that are harmful to the environment, such as dissolved manganese. The proof of metrological compatibility between laboratories and different test methods or techniques is an analytical challenge when complying with environmental laws and regulations, which is the aim of this study. The first step of this study was to compare the results of manganese content in real test samples of produced water between some laboratories that used different test methods, that is, flame atomic absorption spectrophotometry, inductively coupled plasma optical emission spectroscopy, and inductively coupled plasma mass spectrometry. Based on one-way analysis of variance, systematic errors were found. The following step was to visit a specific lab, where one could confirm the relevance of the wavelength parameters, operating conditions for the view configuration, and effects of the saline matrices. Finally, a compatibility assessment between the reference laboratory and a new laboratory, which implemented and validated its analytical methodology based on these analytical adjustments, and the experiences and lessons learned in the previous step, was undertaken by a paired t-test. Full article
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20 pages, 4115 KiB  
Article
Physicochemical Characterization of ‘Moroccan Picholine’ Olive (Olea europaea L.) Oil Produced in Southern Morocco Using Multivariate Statistical Analysis
by Jamila Gagour, Otmane Hallouch, Abderrahim Asbbane, Abdellatif Laknifli, El Hassan Sakar, Khalid Majourhat and Said Gharby
Analytica 2024, 5(1), 119-138; https://doi.org/10.3390/analytica5010008 - 05 Mar 2024
Viewed by 968
Abstract
This study focuses on evaluating the characteristics of olive oil produced in the Taroudant province (southern Morocco), making this the first comprehensive study focusing on olive oil from the ‘Moroccan Picholine’ cultivar. Our objective was to elucidate the distinctive qualities of olive oil [...] Read more.
This study focuses on evaluating the characteristics of olive oil produced in the Taroudant province (southern Morocco), making this the first comprehensive study focusing on olive oil from the ‘Moroccan Picholine’ cultivar. Our objective was to elucidate the distinctive qualities of olive oil from this region, providing valuable insights into its potential contributions to the country’s olive oil sector. For this purpose, several quality criteria (free fatty acids, moisture content, saponification value, and iodine value), oxidation indices (peroxide value, specific UV extinction coefficients, and oxidizability value), and purity indices (fatty acids and sterol composition) were evaluated. Our results reveal minor-to-significant variations (p < 0.05) in the quality and oxidation parameters. Specifically, our results indicate diverse ranges for free fatty acids (0.33–3.62 g/100 g), peroxide values (0.85–4.01 mEq O2/kg oil), K232 (1.68 to 2.73), and K270 (0.09–0.34). Furthermore, consistently high levels of oleic acid (55.8 to 73.1%) and β-sitosterol (94.2 to 97%) were observed in the studied samples. These outcomes were confirmed through the use principal component analysis and hierarchical cluster analysis. Likewise, important correlations were outlined among the studied parameters. Multidimensional analyses not only highlight inherent variations, but also facilitate the classification of the analyzed olive oils into distinct categories. The results suggest that the Taroudant province exhibits favorable conditions for producing high-quality olive oil. Full article
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12 pages, 7154 KiB  
Article
Characterization of Bixin by UV-Visible Spectroscopy and HPLC, and Its Application as Latent Fingermark Developer
by Danielle Tapia Bueno, Amanda Fonseca Leitzke, Rosane Lopes Crizel, Cristina Jansen-Alves, Emanuel Gomes Bertizzolo, Juliana Porciuncula da Silva, Gabrielly Quartieri Sejanes, Kristiane de Cássia Mariotti and Claudio Martin Pereira de Pereira
Analytica 2024, 5(1), 107-118; https://doi.org/10.3390/analytica5010007 - 03 Mar 2024
Viewed by 494
Abstract
Fingerprints are essential for human identification and are valuable tools in criminal investigations. The pursuit of new materials for digital printing is expanding, with increasing interest in natural compounds such as bixin, sourced from annatto seeds. Despite its traditional use as a natural [...] Read more.
Fingerprints are essential for human identification and are valuable tools in criminal investigations. The pursuit of new materials for digital printing is expanding, with increasing interest in natural compounds such as bixin, sourced from annatto seeds. Despite its traditional use as a natural dye with medicinal properties, the potential of bixin in papilloscopy remains largely untapped. In this study, we meticulously extracted bixin from annatto seeds and meticulously developed composites incorporating zinc carbonate (bixin/ZnCO3) and kaolinite (bixin/kaolinite). UV-visible spectroscopy was used for characterization, and the extracted bixin showed absorption peaks at 429, 453, and 481 nm, which were very similar to standard peaks at 429, 457, and 487 nm. The two samples also had the same retention times (7.07 min) according to further liquid chromatography analysis. Sweat pores were easier to detect thanks to the effectiveness of the bixin/ZnCO3 and bixin/kaolinite composites in creating high contrast sebaceous and natural latent fingerprints. These results highlight the composites’ potential as novel and fascinating instruments for papilloscopy applications, which might also improve forensic investigations. Full article
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17 pages, 2278 KiB  
Article
Optimization of Pulsed Electric Field-Based Extraction of Bioactive Compounds from Cannabis sativa Leaves
by Dimitrios Mpakos, Theodoros Chatzimitakos, Vassilis Athanasiadis, Martha Mantiniotou, Eleni Bozinou and Stavros I. Lalas
Analytica 2024, 5(1), 90-106; https://doi.org/10.3390/analytica5010006 - 04 Feb 2024
Viewed by 786
Abstract
The current investigation examines the application of pulsed electric fields (PEFs) for isolating polyphenols from Cannabis sativa var. Futura 75 leaves. Firstly, the solvent composition, which included ethanol, water, and various mixtures of the two, was explored, along with the liquid-to-solid ratio. Subsequently, [...] Read more.
The current investigation examines the application of pulsed electric fields (PEFs) for isolating polyphenols from Cannabis sativa var. Futura 75 leaves. Firstly, the solvent composition, which included ethanol, water, and various mixtures of the two, was explored, along with the liquid-to-solid ratio. Subsequently, the primary parameters associated with PEFs (namely, pulse duration, pulse period, electric field intensity, and treatment duration) were optimized. The extracted samples were analyzed to determine their total polyphenol content (TPC), and individual polyphenols were also evaluated through high-performance liquid chromatography. In addition, the antioxidant activity of the extracts was assessed through ferric-reducing antioxidant power (FRAP) and DPPH assays. The extracts prepared utilizing PEFs were compared to the extracts obtained without PEFs in terms of their TPC, FRAP values, and DPPH activity. The results indicate that the most effective extraction parameters were a pulse duration of 10 μs, a pulse period of 1000 μs, and an electric field strength of 0.9 kV/cm after 25 min of extraction. The most efficient solvent was determined to be a 50% (v/v) mixture of ethanol and water in a 20:1 liquid-to-solid ratio. The extract obtained under the optimal conditions exhibited a ~75% increase in TPC compared to the extract obtained without any application of PEFs, while some individual polyphenols exhibited an increase of up to ~300%. Furthermore, significant increases of ~74% and ~71% were observed in FRAP and DPPH assays. From the information provided, it was observed that the tested variables had an impact on the recovery of polyphenols from C. sativa leaves. Full article
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16 pages, 3602 KiB  
Article
Disposable Voltammetric Immunosensor for Determination and Quantification of Biomarker CA 15-3 in Biological Specimens
by Ana Elisa F. Oliveira, Arnaldo César Pereira, Mayra A. C. Resende and Lucas Franco Ferreira
Analytica 2024, 5(1), 74-89; https://doi.org/10.3390/analytica5010005 - 02 Feb 2024
Viewed by 637
Abstract
A disposable voltammetric immunosensor was developed to measure breast cancer biomarker 15-3 (CA 15-3) in human saliva and serum samples. Screen-printed paper-based electrodes (f-SPE) previously fabricated by our research group using homemade conductive inks were used as transducers, which were later modified only [...] Read more.
A disposable voltammetric immunosensor was developed to measure breast cancer biomarker 15-3 (CA 15-3) in human saliva and serum samples. Screen-printed paper-based electrodes (f-SPE) previously fabricated by our research group using homemade conductive inks were used as transducers, which were later modified only with gold nanoparticles to immobilize anti-CA 15-3 antibodies. The sensor was operated using antigen–antibody interactions in conjunction with a redox species (ferrocyanide potassium) for the indirect determination of the CA 15-3 antigen. The device characterization involved atomic force microscopy (AFM) and electrochemical analysis. Optimization of the construction and response of the immunosensor was achieved at incubation times of 6 h for anti-CA 15-3, 1 h for bovine serum albumin, and 1 h for interaction with CA 15-3. The sensor displays a linear range between 2 and 16 U/mL, with a sensitivity of 0.012 μA/U mL−1, a limit of detection (LOD) of 0.56 U/mL, and a limit of quantification (LOQ) of 1.88 U/mL. The interfering substances minimally affected the signal, with 4.94% response variation, and the reproducibility of the immunosensor demonstrated a relative standard deviation (RSD) of 5.65%. The sensor successfully determined the CA 15-3 concentration in human serum and saliva, demonstrating its potential for clinical analysis. Full article
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20 pages, 1654 KiB  
Review
Insights into Analytical Precision: Understanding the Factors Influencing Accurate Vitamin A Determination in Various Samples
by Yauheni Shastak, Wolf Pelletier and Andrea Kuntz
Analytica 2024, 5(1), 54-73; https://doi.org/10.3390/analytica5010004 - 02 Feb 2024
Cited by 1 | Viewed by 845
Abstract
The accurate assessment of vitamin A in animal feed and tissues is vital for safeguarding animal well-being and ensuring high-quality nutritional feed. However, challenges in achieving precise results persist, necessitating a comprehensive understanding of the influencing factors. This review delves into the historical [...] Read more.
The accurate assessment of vitamin A in animal feed and tissues is vital for safeguarding animal well-being and ensuring high-quality nutritional feed. However, challenges in achieving precise results persist, necessitating a comprehensive understanding of the influencing factors. This review delves into the historical progression of analytical techniques, from colorimetric assays and spectrophotometry to advanced chromatographic methods and non-destructive spectroscopic approaches. Factors influencing analytical precision are scrutinized, encompassing sample preparation, storage conditions, interfering substances, and human errors. The crucial role of quality control and standardized protocols in ensuring the reproducibility and reliability of results is emphasized. Moreover, this review highlights the need for tailored analytical approaches to account for the complexities of sample matrices and the significance of cutting-edge technologies, including on-site analysis and data science integration, in enhancing analytical precision. By acknowledging the challenges and prospects in vitamin A analysis, this paper provides insights for optimizing analytical methodologies and promoting animal welfare and product safety. Full article
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11 pages, 2299 KiB  
Article
A Pre-Trial Study to Identify Species of Origin in Halloumi Cheese Utilising Chemometrics with Near-Infrared and Hyperspectral Imaging Technologies
by Maria Tarapoulouzi, Natasha Logan, Mike Hardy, Holly Montgomery, Simon A. Haughey, Christopher T. Elliott and Charis R. Theocharis
Analytica 2024, 5(1), 17-27; https://doi.org/10.3390/analytica5010002 - 09 Jan 2024
Viewed by 1047
Abstract
Halloumi cheese has recently gained a Protected Designation of Origin (PDO) indicator, which is related to the place (Cyprus) in which halloumi cheese is made. The PDO label is linked with several requirements, e.g., milk species, quantities, etc.; thus, it is important to [...] Read more.
Halloumi cheese has recently gained a Protected Designation of Origin (PDO) indicator, which is related to the place (Cyprus) in which halloumi cheese is made. The PDO label is linked with several requirements, e.g., milk species, quantities, etc.; thus, it is important to study this product regarding authenticity. The utility of using two spectroscopic techniques, hyperspectral imaging (HSI) (400–1000 nm) and conventional near-infrared spectroscopy (NIR) (800–2500 nm) were assessed for the discrimination of 17 Cypriot halloumi cheese types, which could be categorized as of cow or goat–sheep origin. The aim of this study was to obtain spectral information for halloumi cheese using other promising infrared and imaging spectroscopic techniques as a comparison to a previously acquired mid-infrared (MIR) spectroscopy dataset. NIR and HSI are both fast and easy techniques in application, both of which provide significant information in food analysis. Chemometric analysis was crucial for interpreting the spectroscopic data by applying the unsupervised methods: principal component analysis (PCA) and hierarchical cluster analysis (HCA). The HSI model was found to be based intuitively on the appearance of cheese samples after freeze-drying (e.g., color; yellow/white, and texture; oily/dry), while the NIR grouping of samples was determined to be based on composition, mainly fat, protein and lactose content of the cheese samples. The HSI model returned distinct clusters of the two halloumi cheese types, cow and goat–sheep origin, with one outlier (16/17 accuracy; 94%), while the NIR model proved less accurate (13/17; 76%). Full article
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2023

Jump to: 2024, 2022, 2021, 2020

9 pages, 7883 KiB  
Article
Comparison of the Greenness Assessment of Chromatographic Methods Used for Analysis of UV Filters in Cosmetic Samples
by Grażyna Wejnerowska and Izabela Narloch
Analytica 2023, 4(4), 447-455; https://doi.org/10.3390/analytica4040032 - 06 Nov 2023
Viewed by 976
Abstract
Chemical ultraviolet filters are widely used in a variety of cosmetic products to protect the skin from the harmful effects of UV radiation. In order to guarantee consumers’ health, the content in sunscreens is regulated in a number of countries. Many analytical methods [...] Read more.
Chemical ultraviolet filters are widely used in a variety of cosmetic products to protect the skin from the harmful effects of UV radiation. In order to guarantee consumers’ health, the content in sunscreens is regulated in a number of countries. Many analytical methods are used to determine UV filters in cosmetics samples. In recent years, attention has been paid to the fact that the methods should have a small impact on the environment. This work examined the greenness of 10 reported chromatographic methods in the literature for the determination of UV filters in cosmetic samples using two new tools: analytical greenness metric (AGREE) and analytical greenness metric for sample preparation (AGREEprep). Microextraction methods of sample preparation in the AGREEprep assessment show a higher score of greenness. The results recommended the use of both tools to assess the greening of methods before planning laboratory analytical methods to measure their ecological impact on the environment. Full article
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15 pages, 3412 KiB  
Article
A Novel ppb-Level Sensitive and Highly Selective Europium-Based Diketone Luminescent Sensor for the Quantitative Detection of Aluminum Ions in Water Samples
by Nawagamu A. K. Rajitha Perera, Sindhu K. Shankar, Cynthia M. Archambault, Vladimir N. Nesterov, Sreekar B. Marpu, Hao Yan and Mohammad A. Omary
Analytica 2023, 4(4), 432-446; https://doi.org/10.3390/analytica4040031 - 06 Nov 2023
Viewed by 1349
Abstract
A novel Eu(tta)3([4,4′-(t-bu)2-2,2′-bpy)] complex (tta-thenoyltrifluoroacetone), a ratiometric luminescent-based optical sensor for the quantitative determination of aluminum ion, is synthesized and characterized using XRD and 1H NMR. The XRD data reveal the slightly distorted octahedral structure. The complex displays [...] Read more.
A novel Eu(tta)3([4,4′-(t-bu)2-2,2′-bpy)] complex (tta-thenoyltrifluoroacetone), a ratiometric luminescent-based optical sensor for the quantitative determination of aluminum ion, is synthesized and characterized using XRD and 1H NMR. The XRD data reveal the slightly distorted octahedral structure. The complex displays a bright red emission at 613 nm in methanol which is characteristic of europium (III) complexes. Upon the addition of Al3+ ions, the red emission disappears, and a new blue emission at 398 nm emerges, manifesting the ratiometric nature of the complex. The turn-off of the red emission and turn-on of the blue emission are attributed to Eu-Al trans-metalation, as supported by Raman data that show the emergence of Al-O vibrations at 418, 495, and 608 cm−1 concomitant with the disappearance of Eu-O and Eu-N bond vibrations. Most aluminum sensors are known to suffer from interferences from other metals including Cu2+, Co2+, and Cd2+. However, the sensor reported here is tested for 11 common cations and shows no interference on sensitivity. To the best of our knowledge, this is the first known Eu-based luminescence sensor that successfully exhibited the ability to detect aluminum ions in ppb levels in aqueous environments. The calculated Al3+ binding constant is 2.496 × 103 ± 172. The complex shows a linear relationship in the range of 0–47.6 ppb (1.76 × 10−6 M) Al3+ and the limit of detection (LOD) is 4.79 ppb (1.77 × 10−7 M) in MeOH. ICP-OES is used for validation of the sensor complex in water and then it was used for quantitative detection of Al3+ ions in water as a real-life application. The complex can accurately detect Al3+ ions in the range of 4.97–24.9 ppb (1.84 × 10−7 M–9.2 × 10−7 M) with an LOD of 8.11 ppb (2.99 × 10−7 M). Considering that the aluminum ion serves no recognized function within the human body, its accumulation can lead to severe neurological disorders, including Parkinson’s and Alzheimer’s diseases. With the LOD value significantly lower than the WHO-recommended maximum permissible level of 200 ppb for aluminum in drinking water, even without high-power laser-aided signal enhancement, the sensor shows promise for detecting trace amounts of aluminum contamination in water. Therefore, it can significantly aid in the monitoring of even the smallest aluminum ion contamination in drinking water, industrial effluents, and natural water bodies. Full article
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17 pages, 13518 KiB  
Article
Gold Nanoclusters Prepared in the Presence of Adenosine Monophosphate and Citrate: Factorial-Based Synthesis Optimization and Sensing Properties
by Evgeny Karpushkin, Ekaterina Mesnyankina and Vladimir Sergeyev
Analytica 2023, 4(4), 415-431; https://doi.org/10.3390/analytica4040030 - 14 Oct 2023
Viewed by 942
Abstract
Gold nanoclusters are peculiar objects promising in view of qualitative and quantitative determination of various species, including heavy metal ions and biological molecules. We have recently discovered that introducing sodium azide in the reaction mixture during gold nanocluster synthesis in the presence of [...] Read more.
Gold nanoclusters are peculiar objects promising in view of qualitative and quantitative determination of various species, including heavy metal ions and biological molecules. We have recently discovered that introducing sodium azide in the reaction mixture during gold nanocluster synthesis in the presence of citrate and adenosine monophosphate can tune the product emission from blue to yellow. Taking advantage of the factorial design of the experiment, we have optimized the synthesis conditions to obtain pure blue and yellow emitters and investigate their sensitivity to a series of inorganic salts. The experiments have revealed selective quenching of the nanocluster’s fluorescence in the presence of mercury(II) ions. Full article
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18 pages, 2404 KiB  
Article
Determination of Capecitabine and Its Metabolites in Plasma of Egyptian Colorectal Cancer Patients
by Sara Shamseldin, Liza Samir Botros, Salem Eid Salem, Sahar Abdel-Maksoud, Mohamed Zakaria Gad and Rasha Sayed Hanafi
Analytica 2023, 4(4), 397-414; https://doi.org/10.3390/analytica4040029 - 01 Oct 2023
Viewed by 1750
Abstract
The incidence of colorectal cancer (CRC) is increasing worldwide. It has variable signs and symptoms starting from changes in bowel habit to nausea and vomiting. Chemotherapeutic agents are often prescribed in CRC such as Capecitabine (CCB) and 5-Fluorouracil (FU). CCB is the prodrug [...] Read more.
The incidence of colorectal cancer (CRC) is increasing worldwide. It has variable signs and symptoms starting from changes in bowel habit to nausea and vomiting. Chemotherapeutic agents are often prescribed in CRC such as Capecitabine (CCB) and 5-Fluorouracil (FU). CCB is the prodrug of FU in oral dosage form, which makes it preferable by physicians, since no hospitalization is needed for drug administration. CCB is activated to FU in a three-step reaction producing 5′-deoxy-5-fluorocytidine (DFCR) (by carboxylesterase (CES) enzyme), then 5′-deoxy-5-fluorouridine (DFUR) (by cytidine deaminase (CDD) enzyme) and finally FU (by thymidine phosphorylase (TP) enzyme), the active form, which is later deactivated to give 5,6-dihydro-5-fluorouracil (DHFU). Different patients exhibit variable drug responses and adverse in response to CCB therapy, despite being treated by the same dose, which could be attributed to the occurrence of different possible enzyme single nucleotide polymorphisms (SNPs) along the activation and deactivation pathways of CCB. The most commonly occurring toxicities in CCB therapy are hand-foot syndrome and diarrhea. This study aims at developing and validating a new method for the simultaneous determination of CCB and its metabolites by HPLC-UV, followed by a correlation study with the toxicities occurring during therapy, where predictions of toxicity could be based on metabolites’ levels instead of the tedious process of genotyping. A new superior analytical method was optimized by a quality-by-design approach using DryLab® 2000 software achieving a baseline resolution of the six analytes within the least possible gradient time of 10 min. The method also showed linearity (in a range from 1 to 500 μg/mL), accuracy, precision and robustness upon validation: The LOD was found to be 3.0 ng/mL for DHFU and CCB, and 0.3 ng/mL for DFUR, DFCR and FU. The LOQ was found to be 10.0 ng/mL for DHFU and CCB, and 1.0 ng/mL for DFUR, DFCR and FU. The clinical results showed a positive correlation between the concentration of DFCR and mucositis and between the concentration of DFUR and hand-foot syndrome, confirming that this technique could be used for predicting such toxicities. Full article
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12 pages, 2160 KiB  
Article
Antibody Titer Prediction from Serum Immunodiffusion Test of Patients with Paracoccidioidomycosis Using Infrared Spectroscopy and Chemometrics
by Alessandra Koehler, Maria Lúcia Scroferneker, Paulo Cezar de Moraes, Beatriz Aparecida Soares Pereira, Ricardo de Souza Cavalcante, Rinaldo Pôncio Mendes and Valeriano Antonio Corbellini
Analytica 2023, 4(3), 385-396; https://doi.org/10.3390/analytica4030028 - 06 Sep 2023
Viewed by 1221
Abstract
Paracoccidioidomycosis (PCM) is a systemic mycosis caused by fungi of the genus Paracoccidioides. Serological tests are auxiliary in the diagnosis of PCM. However, the lack of standardization is a central problem in serodiagnosis and antibody titration. The objective of this study was [...] Read more.
Paracoccidioidomycosis (PCM) is a systemic mycosis caused by fungi of the genus Paracoccidioides. Serological tests are auxiliary in the diagnosis of PCM. However, the lack of standardization is a central problem in serodiagnosis and antibody titration. The objective of this study was to propose a methodology based on Fourier transform infrared spectroscopy (FTIR) for predicting antibody titers in patients with PCM. A total of 118 serum samples from patients with PCM were included, for which antibody titration using double immunodiffusion (DID) was previously performed. Serum samples were analyzed by attenuated total reflection (ATR)-FTIR and a supervised analysis with partial least squares regression (PLS) was used to predict the antibody titers. The PLS model with two latent variables and with the use of one orthogonal signal correction (OSC) showed a determination coefficient (R2) higher than 0.9999 for both the calibration and prediction set. The model was able to predict the antibody titers from patients with PCM with a minimal error. Therefore, modeling with FTIR/ATR and multivariate calibration proved to be a fast and highly accurate method for antibody titration, replacing the need for antigen production and performance of traditional serological tests. Full article
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13 pages, 1684 KiB  
Article
Revealing the Ion Chemistry Occurring in High Kinetic Energy-Ion Mobility Spectrometry: A Proof of Principle Study
by Florentin Weiss, Christoph Schaefer, Stefan Zimmermann, Tilmann D. Märk and Chris A. Mayhew
Analytica 2023, 4(2), 113-125; https://doi.org/10.3390/analytica4020010 - 23 Apr 2023
Viewed by 1510
Abstract
Here, we present proof of principle studies to demonstrate how the product ions associated with the ion mobility peaks obtained from a High Kinetic Energy-Ion Mobility Spectrometer (HiKE-IMS) measurement of a volatile can be identified using a Proton Transfer Reaction/Selective Reagent Ion-Time-of-Flight-Mass Spectrometer [...] Read more.
Here, we present proof of principle studies to demonstrate how the product ions associated with the ion mobility peaks obtained from a High Kinetic Energy-Ion Mobility Spectrometer (HiKE-IMS) measurement of a volatile can be identified using a Proton Transfer Reaction/Selective Reagent Ion-Time-of-Flight-Mass Spectrometer (PTR/SRI-ToF-MS) when operating both instruments at the same reduced electric field value and similar humidities. This identification of product ions improves our understanding of the ion chemistry occurring in the ion source region of a HiKE-IMS. The combination of the two analytical techniques is needed, because in the HiKE-IMS three reagent ions (NO+, H3O+ and O2+•) are present at the same time in high concentrations in the reaction region of the instrument for reduced electric fields of 100 Td and above. This means that even with a mass spectrometer coupled to the HiKE-IMS, the assignment of the product ions to a given reagent ion to a high level of confidence can be challenging. In this paper, we demonstrate an alternative approach using PTR/SRI-ToF-MS that allows separate investigations of the reactions of the reagent ions NO+, H3O+ and O2+•. In this study, we apply this approach to four nitrile containing organic compounds, namely acetonitrile, 2-furonitrile, benzonitrile and acrylonitrile. Both the HiKE-IMS and the PTR/SRI-ToF-MS instruments were operated at a commonly used reduced electric field strength of 120 Td and with gas flows at the same humidities. Full article
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12 pages, 1773 KiB  
Article
Human Milk: Fast Determination of Docosahexaenoic Acid (DHA)
by Mahyara Markievicz Mancio Kus-Yamashita, Cristiane Bonaldi Cano, Vânia Claudia Barros Monteiro and Regina Maria Catarino
Analytica 2023, 4(1), 54-65; https://doi.org/10.3390/analytica4010006 - 03 Mar 2023
Cited by 1 | Viewed by 2084
Abstract
Human milk provides all the nutrients required by babies during the first six months of their life. Human milk lipids represent the main source of energy, contributing almost 50% of the total energy content. Additionally, fatty acids ensure the correct development of children [...] Read more.
Human milk provides all the nutrients required by babies during the first six months of their life. Human milk lipids represent the main source of energy, contributing almost 50% of the total energy content. Additionally, fatty acids ensure the correct development of children in the prenatal, postnatal, and infant phases. Docosahexaenoic acid (DHA) is essential for visual and cognitive development, and its presence during childhood can affect long-term health. This study aimed to optimize and validate a methodology for the direct determination of DHA in human milk. We used 20 samples of human milk from lactating women living in the city of Itu, São Paulo, who attended Basic Health Units from September 2019 to September 2020, and a sample of certified reference material from the National Institute of Standards and Technology. The proposed methodology consists of a validated mixed transesterification process without prior lipid extraction, optimized by factorial design. This methodology can be successfully used in human milk samples as it is both precise and accurate. The values of DHA in the sampled milks were similar to those in European countries and lower than those in Asian countries due to diet. Full article
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9 pages, 2522 KiB  
Communication
Baseline Correction for HPLC Chromatograms by Using Free Open-Source Software
by Kostas Gkountanas, Ioanna Dagla, Evangelos Gikas, Anđelija Malenović and Yannis Dotsikas
Analytica 2023, 4(1), 45-53; https://doi.org/10.3390/analytica4010005 - 08 Feb 2023
Viewed by 3426
Abstract
Chromatograms with overlapping peaks and a baseline rise or upset constitute a great challenge for analysts. Such a case regarding the analysis of bupropion hydrochloride and its 5 impurities in a tablet formulation was used as a model. A baseline correction technique for [...] Read more.
Chromatograms with overlapping peaks and a baseline rise or upset constitute a great challenge for analysts. Such a case regarding the analysis of bupropion hydrochloride and its 5 impurities in a tablet formulation was used as a model. A baseline correction technique for liquid chromatography coupled with diode array detection is described by using Rstudio. The asymmetry least squares (ALS) algorithm was used as implemented in the “baseline” package, with parameters lambda and p set to 4 and 0.05, respectively. Peak deconvolution and subsequent integration and area quantification were accomplished through Fytik software. Chromatographic data from the validation procedure were utilized to demonstrate the feasibility of the suggested method and whether this correction affects the outcome of the validation study. Finally, a robustness study was carried out in order to shed light on the factors that have a more significant influence on the baseline correction, showing the reliability of this procedure through random changes in its parameters. Full article
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18 pages, 3346 KiB  
Article
Development of an Inexpensive and Comparable Microplastic Detection Method Using Fluorescent Staining with Novel Nile Red Derivatives
by Michael Toni Sturm, Erika Myers, Dennis Schober, Anika Korzin and Katrin Schuhen
Analytica 2023, 4(1), 27-44; https://doi.org/10.3390/analytica4010004 - 01 Feb 2023
Cited by 9 | Viewed by 4248
Abstract
Fluorescent staining of microplastics as a detection method is consistently gaining importance in microplastics research, as it is fast, easy to use, and requires low technical effort. In this study, a complete procedure was developed, from sample collection to sample processing and detection, [...] Read more.
Fluorescent staining of microplastics as a detection method is consistently gaining importance in microplastics research, as it is fast, easy to use, and requires low technical effort. In this study, a complete procedure was developed, from sample collection to sample processing and detection, to measure microplastics with low cost and time requirements. The developed procedure was tested by measuring the microplastics in the effluent of a German wastewater treatment plant over a period of one year. The results show that the process is especially well suited to investigate temporal variations of microplastic contamination, which requires a large number of samples to be processed. Further, the precision and selectivity of the detection process could be improved by applying newly developed Nile red derivatives for fluorescent staining. A low budget modification of a microscope for fluorescent imaging is compared to a modification with precise optical bandpass filters. A script enabling automated microplastic detection and counting was developed, improving the accuracy and comparability of the process. Full article
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15 pages, 10699 KiB  
Article
Microplastics and Per- and Polyfluoroalkyl Substances (PFAS) Analysis in Sea Turtles and Bottlenose Dolphins along Mississippi’s Coast
by Chanaka M. Navarathna, Hannah Pray, Prashan M. Rodrigo, Beatrice Arwenyo, Cassidy McNeely, Henry Reynolds, Natalie Hampton, Katherine Lape, Katie Roman, Maddie Heath, Sean Stokes, Sameera R. Gunatilake, Gombojav Ariunbold, Felio Perez, Rooban V. K. G. Thirumalai, EI Barbary Hassan, Islam Elsayed, Dinesh Mohan, Ashli Brown, Debra Moore, Stephen Reichley, Mark Lawrence and Todd E. Mlsnaadd Show full author list remove Hide full author list
Analytica 2023, 4(1), 12-26; https://doi.org/10.3390/analytica4010003 - 18 Jan 2023
Cited by 2 | Viewed by 4639
Abstract
Global plastic production and usage has increased annually for decades and microplastic pollutants (≤5 mm) are a growing concern. Microplastics in surface waters can adsorb and desorb harmful chemicals such as per- and polyfluoroalkyl substances (PFAS). Microplastics can accumulate across all tropic levels [...] Read more.
Global plastic production and usage has increased annually for decades and microplastic pollutants (≤5 mm) are a growing concern. Microplastics in surface waters can adsorb and desorb harmful chemicals such as per- and polyfluoroalkyl substances (PFAS). Microplastics can accumulate across all tropic levels in the marine food web. The purpose of this research was to analyze the stomach and intestinal contents of stranded (Mississippi coast) bottlenose dolphins and sea turtles for the presence of microplastics and commonly found PFAS, PFOS, PFOA, and GenX. Gut contents were digested (10% KOH in 50% MeOH) and then analyzed for microplastics using pyrolysis gas chromatography-mass spectrometry (Pyro-GC-MS), Nile red microscopy, X-ray photo electron spectroscopy (XPS), and Raman spectroscopy. Digested sample filtrate was pre-concentrated using solid-phase extraction (SPE) before PFAS liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The PFOS extraction and analysis had 98.6% recovery when validated with certified pike‒perch fish reference material. The Nile red testing on most samples revealed the presence of microplastics (Table S1). The Pyro-GC-MS results from two samples confirmed the presence of the plasticizer acetamide. The Raman spectroscopy analysis indicated characteristic plastic peaks corresponding to polystyrene in one sample. PFOS (95.5 to 1,934.5 µg/kg) was detected in three dolphin stomach samples. This project is part of a long-term study with the goal of a better understanding of microplastics and PFAS environmental contamination and their impact on bottlenose dolphins and sea turtles. Full article
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9 pages, 867 KiB  
Article
Development and Validation of a Simple HPLC-UV Assay Method for Determination of Levetiracetam Concentrations in Human Plasma
by Maged Kharouba and Sherif Hanafy Mahmoud
Analytica 2023, 4(1), 1-9; https://doi.org/10.3390/analytica4010001 - 04 Jan 2023
Cited by 1 | Viewed by 2637
Abstract
Levetiracetam (LEV) is a broad spectrum antiseizure medication that is used in various seizure types. There is evidence that therapeutic drug monitoring (TDM) of LEV is of value in selected patient populations, therefore determination of LEV plasma concentrations is essential. Herein we developed [...] Read more.
Levetiracetam (LEV) is a broad spectrum antiseizure medication that is used in various seizure types. There is evidence that therapeutic drug monitoring (TDM) of LEV is of value in selected patient populations, therefore determination of LEV plasma concentrations is essential. Herein we developed and validated a simple, reproducible, and practical method for the quantification of LEV concentrations in human plasma samples using high performance liquid chromatography (HPLC). Plasma samples (0.3 mL) deproteinization was done using acetonitrile. HPLC chromatographic separation of plasma samples was accomplished by reversed phase C18 column. The mobile phase constituted water and acetonitrile (90:10, v/v) ran at flow rate of 1 mL/min. Signal acquisition was conducted at a wavelength of 192 nm. Calibration curves showed excellent linearity (Correlation coefficient r2 > 0.99) over a concentration range of 3–80 μg/mL. Both inter and intraday assay accuracy and precision were less than 8% (except for the lowest limit of quantification was within 20%). Elution time was 15 min. The developed method excluded the use of buffers and utilized small volumes of plasma samples with simple mobile phase composition. Therefore, our method could be practically applied to routine TDM. Full article
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2022

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9 pages, 884 KiB  
Technical Note
Magnet Integrated Fabric Phase Sorptive Extraction (MI-FPSE): A Powerful Green(er) Alternative for Sample Preparation
by Victoria Samanidou and Abuzar Kabir
Analytica 2022, 3(4), 439-447; https://doi.org/10.3390/analytica3040030 - 02 Dec 2022
Cited by 2 | Viewed by 1804
Abstract
Green(er) sample preparation technologies still dominate as the anticipated improvement in all analytical protocols. Separation scientists all over the world continuously strive to comply with the Green Analytical Chemistry (GAC) demands. To follow this trend, microextraction techniques are constantly evolving to bridge the [...] Read more.
Green(er) sample preparation technologies still dominate as the anticipated improvement in all analytical protocols. Separation scientists all over the world continuously strive to comply with the Green Analytical Chemistry (GAC) demands. To follow this trend, microextraction techniques are constantly evolving to bridge the gap between Green Analytical Chemistry and sample pretreatment. A research group from Florida International University, Miami, Florida has introduced fabric phase sorptive extraction (FPSE) in 2014 that was considered as a new milestone in microextraction technologies at that time. Two years later, the same research group introduced an advantageous innovative configuration that combines the stirring and extraction mechanism into a single sample preparation device, keeping all the benefits originally offered by classical FPSE. Magnet integrated fabric phase sorptive extraction (MI-FPSE) was eventually introduced as a new, advantageous implementation of FPSE. This device exhibits the advantageous role of the increase in extraction kinetics through sample diffusion, resulting in improved extraction efficiency of the microextraction device and supports the need for combining processes for better promotion and implementation of the principles of Green Analytical Chemistry. The applications of MI-FPSE are presented herein, showing the essential role that this technique can play in analytical and bioanalytical sample preparation. Full article
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12 pages, 1237 KiB  
Article
Optimized Spectrophotometry Method for Starch Quantification
by Palina Bahdanovich, Kevin Axelrod, Andrey Y. Khlystov and Vera Samburova
Analytica 2022, 3(4), 394-405; https://doi.org/10.3390/analytica3040027 - 26 Oct 2022
Cited by 2 | Viewed by 9597
Abstract
Starch is a polysaccharide that is abundantly found in nature and is generally used as an energy source and energy storage in many biological and environmental processes. Naturally, starch tends to be in miniscule amounts, creating a necessity for quantitative analysis of starch [...] Read more.
Starch is a polysaccharide that is abundantly found in nature and is generally used as an energy source and energy storage in many biological and environmental processes. Naturally, starch tends to be in miniscule amounts, creating a necessity for quantitative analysis of starch in low-concentration samples. Existing studies that are based on the spectrophotometric detection of starch using the colorful amylose–iodine complex lack a detailed description of the analytical procedure and important parameters. In the present study, this spectrophotometry method was optimized, tested, and applied to studying starch content of atmospheric bioaerosols such as pollen, fungi, bacteria, and algae, whose chemical composition is not well known. Different experimental parameters, including pH, iodine solution concentrations, and starch solution stability, were tested, and method detection limit (MDL) and limit of quantification (LOQ) were determined at 590 nm. It was found that the highest spectrophotometry signal for the same starch concentration occurs at pH 6.0, with an iodine reagent concentration of 0.2%. The MDL was determined to be 0.22 μg/mL, with an LOQ of 0.79 μg/mL. This optimized method was successfully tested on bioaerosols and can be used to determine starch content in low-concentration samples. Starch content in bioaerosols ranged from 0.45 ± 0.05 (in bacteria) to 4.3 ± 0.06 μg/mg (in fungi). Full article
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9 pages, 3853 KiB  
Article
Signal “Off-On” Biosensor Based on Fluorescence Resonance Energy Transfer (FRET) for Detection of Sorghum Mosaic Virus
by Zhenlong Han, Pengfei Du, Ronghui Wen, Baoshan Chen and Xipu He
Analytica 2022, 3(4), 385-393; https://doi.org/10.3390/analytica3040026 - 18 Oct 2022
Viewed by 1603
Abstract
A fluorescence off-on method for the detection of Sorghum mosaic virus (SrMV) based on fluorescence resonance energy transfer (FRET) was developed in this study. The biosensor was realized by the adsorption of SrMV coat protein (CP) on gold nanoparticle (AuNP) and conjugation of [...] Read more.
A fluorescence off-on method for the detection of Sorghum mosaic virus (SrMV) based on fluorescence resonance energy transfer (FRET) was developed in this study. The biosensor was realized by the adsorption of SrMV coat protein (CP) on gold nanoparticle (AuNP) and conjugation of anti-SrMV antibody (Ab) on cadmium telluride quantum dot (CdTe QD). The optimum quenching efficiency was about 50% obtained at a CdTe QD-Ab/AuNP-CP ratio of 1:7. Moreover, the feasibility of the developed biosensor was verified by the detection of purified CP and the limit of detection was estimated as 0.02 μg/mL. This strategy was also successfully applied to monitor SrMV CP in plant sap with a recovery rate between 97.7 and 107.4%. The developed biosensor is a simple, rapid, and efficient technique which does not need excessive washing and separation steps. Full article
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14 pages, 798 KiB  
Article
Performance of Spectrophotometric and Fluorometric DNA Quantification Methods
by Brigitte Bruijns, Tina Hoekema, Lisa Oomens, Roald Tiggelaar and Han Gardeniers
Analytica 2022, 3(3), 371-384; https://doi.org/10.3390/analytica3030025 - 16 Sep 2022
Cited by 2 | Viewed by 7434
Abstract
Accurate DNA quantification is a highly important method within molecular biology. Methods widely used to quantify DNA are UV spectrometry and fluorometry. In this research, seven different DNA samples and one blank (MilliQ ultrapure water) were quantified by three analysts using one spectrophotometric [...] Read more.
Accurate DNA quantification is a highly important method within molecular biology. Methods widely used to quantify DNA are UV spectrometry and fluorometry. In this research, seven different DNA samples and one blank (MilliQ ultrapure water) were quantified by three analysts using one spectrophotometric (i.e., a NanoDrop instrument) and three fluorometric (i.e., the AccuGreen High Sensitivity kit, the AccuClear Ultra High Sensitivity kit, and the Qubit dsDNA HS Assay kit) methods. An analysis of variance (ANOVA) scheme was used to determine the influence of the analyst, the method, and the combination of analyst and method, on DNA quantification. For most samples, the measured DNA concentration was close to or slightly above the concentration of 10 ng/μL as specified by the supplier. Results obtained by the three analysts were equal. However, it was found that, compared to the fluorometric kits, the used spectrophotometric instrument in the case of fish DNA samples tends to overestimate the DNA concentration. Therefore, if sufficient sample volume is available, a combination of a spectrophotometric and a fluorometric method is recommended for obtaining data on the purity and the dsDNA concentration of a sample. Full article
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36 pages, 3892 KiB  
Article
Development of a High-Accuracy Statistical Model to Identify the Key Parameter for Methane Adsorption in Metal-Organic Frameworks
by Kaushik Sivaramakrishnan and Eyas Mahmoud
Analytica 2022, 3(3), 335-370; https://doi.org/10.3390/analytica3030024 - 06 Sep 2022
Cited by 1 | Viewed by 1892
Abstract
The geometrical and topological features of metal-organic frameworks (MOFs) play an important role in determining their ability to capture and store methane (CH4). Methane is a greenhouse gas that has been shown to be more dangerous in terms of contributing to [...] Read more.
The geometrical and topological features of metal-organic frameworks (MOFs) play an important role in determining their ability to capture and store methane (CH4). Methane is a greenhouse gas that has been shown to be more dangerous in terms of contributing to global warming than carbon dioxide (CO2), especially in the first 20 years of its release into the atmosphere. Its accelerated emission increases the rate of global temperature increase and needs to be addressed immediately. Adsorption processes have been shown to be effective and efficient in mitigating methane emissions from the atmosphere by providing an enormous surface area for methane storage. Among all the adsorbents, MOFs were shown to be the best adsorbents for methane adsorption due to their higher favorable steric interactions, the presence of binding sites such as open metal sites, and hydrophobic pockets. These features may not necessarily be present in carbonaceous materials and zeolites. Although many studies have suggested that the main reason for the increased storage efficiencies in terms of methane in the MOFs is the high surface area, there was some evidence in certain research works that methane storage performance, as measured by uptakes and deliveries in gravimetric and volumetric units, was higher for certain MOFs with a lower surface area. This prompted us to find out the most significant property of the MOF, whether it be material-based or pore-based, that has the maximum influence on methane uptake and delivery, using a comprehensive statistical approach that has not previously been employed in the methane storage literature. The approach in our study employed various chemometric techniques, including simple and multiple linear regression (SLR and MLR), combined with different types of multicollinearity diagnostics, partial correlations, standardized coefficients, and changes in regression coefficient estimates and their standard errors, applied to both the SLR and MLR models. The main advantages of this statistical approach are that it is quicker, provides a deeper insight into experimental data, and highlights a single, most important, parameter for MOF design and tuning that can predict and maximize the output storage and capture performance. The significance of our approach is that it was modeled purely based on experimental data, which will capture the real system, as opposed to the molecular simulations employed previously in the literature. Our model included data from ~80 MOFs and eight properties related to the material, pore, and thermodynamics (isosteric adsorption energy). Successful attempts to model the methane sorption process have previously been conducted using thermodynamic approaches and by developing adsorption performance indicators, but these are either too complex or time-consuming and their data covers fewer than 10 MOFs and a maximum of three MOF properties. By comparing the statistical metrics between the models, the most important and statistically significant property of the MOF was determined, which will be crucial when designing MOFs for use in storing and delivering methane. Full article
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10 pages, 1761 KiB  
Article
Measurement of Radon Concentration in Water within Ojo Axis of Lagos State, Nigeria
by Mostafa Mostafa, M. A. Olaoye, A. K. Ademola, O. A. Jegede, A. A. Saka and Hyam Khalaf
Analytica 2022, 3(3), 325-334; https://doi.org/10.3390/analytica3030023 - 02 Sep 2022
Cited by 4 | Viewed by 2503
Abstract
Background: The problem of radon (Radon-222) in water is one of the daily health hazards faced by those in Ojo Axis, Nigeria. Therefore, continuous monitoring of radon contamination in different types of water is essential. In the present work, sixteen groundwater and surface-water [...] Read more.
Background: The problem of radon (Radon-222) in water is one of the daily health hazards faced by those in Ojo Axis, Nigeria. Therefore, continuous monitoring of radon contamination in different types of water is essential. In the present work, sixteen groundwater and surface-water samples (wells, boreholes, and sachets) were collected from six different locations within the Ojo Local Government area in Nigeria. The water samples collected were stored in 75 cl bottles that were already sterilized with distilled water to avoid contamination. Water samples were then taken to the laboratory for the analysis of radon levels using a RAD7, an active electronic device produced by the Durridge Company in the USA. The radon level in the water is higher than the safe limits of 11.1 Bq/L, as per EPA regulations, except for two sample points from the studied areas. The total annual effective doses from ingestion and inhalation for drinking and groundwater were higher than the safe limit of 0.1 mSv y−1 that is recommended by the World Health Organization and the European Union Commission. Conclusions: The obtained results underline the importance of the development and/or updating of databases regarding radon levels in drinking and groundwater in the Ojo Local Government area in Nigeria. Full article
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13 pages, 779 KiB  
Review
Analytical Chemistry: Tasks, Resolutions and Future Standpoints of the Quantitative Analyses of Environmental Complex Sample Matrices
by Enrica Rosato, Giuseppe Maria Merone, Marcello Locatelli, Cristian D’Ovidio, Martina Bonelli, Ugo de Grazia, Francesco Santavenere, Sandra Rossi, Imran Ali, Halil Ibrahim Ulusoy, Abuzar Kabir and Fabio Savini
Analytica 2022, 3(3), 312-324; https://doi.org/10.3390/analytica3030022 - 26 Aug 2022
Viewed by 2117
Abstract
Currently, the challenges that analytical chemistry has to face are ever greater and more complex both from the point of view of the selectivity of analytical methods and their sensitivity. This is especially true in quantitative analysis, where various methods must include the [...] Read more.
Currently, the challenges that analytical chemistry has to face are ever greater and more complex both from the point of view of the selectivity of analytical methods and their sensitivity. This is especially true in quantitative analysis, where various methods must include the development and validation of new materials, strategies, and procedures to meet the growing need for rapid, sensitive, selective, and green methods. In this context, given the International Guidelines, which over time, are updated and which set up increasingly stringent “limits”, constant innovation is required both in the pre-treatment procedures and in the instrumental configurations to obtain reliable, accurate, and reproducible information. In addition, the environmental field certainly represents the greatest challenge, as analytes are often present at trace and ultra-trace levels. These samples containing analytes at ultra-low concentration levels, therefore, require very labor-intensive sample preparation procedures and involve the high consumption of organic solvents that may not be considered “green”. In the literature, in recent years, there has been a strong development of increasingly high-performing sample preparation techniques, often “solvent-free”, as well as the development of hyphenated instrumental configurations that allow for reaching previously unimaginable levels of sensitivity. This review aims to provide an update of the most recent developments currently in use in sample pre-treatment and instrument configurations in the environmental field, also evaluating the role and future developments of analytical chemistry in light of upcoming challenges and new goals yet to be achieved. Full article
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10 pages, 1814 KiB  
Brief Report
Comprehensive Examination of Cu, Pb, Zn, Fe, Mn and Cd in Lackawanna County Waters, Northeastern Pennsylvania: A Brief Report
by Gerard G. Dumancas, Jake R. Butka and Adam M. Mehall
Analytica 2022, 3(3), 302-311; https://doi.org/10.3390/analytica3030021 - 01 Aug 2022
Viewed by 3120
Abstract
Lackawanna, a US county seat in Northeastern Pennsylvania has an estimated population of 216,000 in 2020. Over the years, it has been reported that several bodies of water found within the county have been contaminated with various metals. However, a comprehensive examination of [...] Read more.
Lackawanna, a US county seat in Northeastern Pennsylvania has an estimated population of 216,000 in 2020. Over the years, it has been reported that several bodies of water found within the county have been contaminated with various metals. However, a comprehensive examination of the presence of these metals has not been conducted. The goal of this brief report was to perform a preliminary quantitative determination of the concentration of various metals found in Lackawanna County water sources. The sources analyzed included Lake Scranton, the Lackawanna River, the Griffin Reservoir, and Keyser Creek. Samples were taken from each source and analyses of copper, lead, zinc, iron, manganese, and cadmium using atomic absorption spectroscopy were performed. A copper concentration of 0.100 ppm was found in the Griffin Reservoir, and 0.380 ppm of iron was found in the Lackawanna River. The concentration of copper and iron in the Griffin Reservoir and Lackawanna River, respectively, were determined to be within safe levels according to guidelines set by the US Environmental Protection Agency. Full article
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15 pages, 5208 KiB  
Review
Deep Learning for Raman Spectroscopy: A Review
by Ruihao Luo, Juergen Popp and Thomas Bocklitz
Analytica 2022, 3(3), 287-301; https://doi.org/10.3390/analytica3030020 - 19 Jul 2022
Cited by 40 | Viewed by 10033
Abstract
Raman spectroscopy (RS) is a spectroscopic method which indirectly measures the vibrational states within samples. This information on vibrational states can be utilized as spectroscopic fingerprints of the sample, which, subsequently, can be used in a wide range of application scenarios to determine [...] Read more.
Raman spectroscopy (RS) is a spectroscopic method which indirectly measures the vibrational states within samples. This information on vibrational states can be utilized as spectroscopic fingerprints of the sample, which, subsequently, can be used in a wide range of application scenarios to determine the chemical composition of the sample without altering it, or to predict a sample property, such as the disease state of patients. These two examples are only a small portion of the application scenarios, which range from biomedical diagnostics to material science questions. However, the Raman signal is weak and due to the label-free character of RS, the Raman data is untargeted. Therefore, the analysis of Raman spectra is challenging and machine learning based chemometric models are needed. As a subset of representation learning algorithms, deep learning (DL) has had great success in data science for the analysis of Raman spectra and photonic data in general. In this review, recent developments of DL algorithms for Raman spectroscopy and the current challenges in the application of these algorithms will be discussed. Full article
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15 pages, 1579 KiB  
Article
A Simple and Reliable Liquid Chromatographic Method for Simultaneous Determination of Five Benzodiazepine Drugs in Human Plasma
by Hassan M. Albishri, Naflaa A. Aldawsari and Deia Abd El-Hady
Analytica 2022, 3(2), 251-265; https://doi.org/10.3390/analytica3020018 - 16 Jun 2022
Cited by 1 | Viewed by 3752
Abstract
Benzodiazepines (BZDs) are one of the most important drugs that have been used in the treatment of neuropsychological disorders. Indeed, BZDs are abused by drug addicts regardless of their therapeutic uses. Therefore, it was important in forensic and clinical toxicology to reach an [...] Read more.
Benzodiazepines (BZDs) are one of the most important drugs that have been used in the treatment of neuropsychological disorders. Indeed, BZDs are abused by drug addicts regardless of their therapeutic uses. Therefore, it was important in forensic and clinical toxicology to reach an easy and reliable method for the screening and quantification of BZDs in the human plasma matrix. In the current work, five BZDs, namely bromazepam, clonazepam, lorazepam, nordiazepam and diazepam were simultaneously separated and detected by a simple and reliable RPLC method in a human plasma matrix. Isocratic mobile elution consisting of 20 mmol L−1 phosphate buffer (pH 7.0) and methanol (50:50, v/v) on a Symmetry C18 column was employed. The flow rate, wavelength and column temperature were fixed at 1.0 mL min−1, 214 nm and 40 °C, respectively. The proposed method was validated, giving a linearity within the concentration ranges 5–500 ng mL−1 for bromazepam and diazepam, 3–500 ng mL−1 for clonazepam and lorazepam and 1–500 ng mL−1 for nordiazepam with a determination coefficient (R2) more than 0.9992. The LOD values for the selected BZDs ranged from 0.54 to 2.32 and from 1.78 to 7.65 ng mL−1 for standard methanolic and plasma matrices, respectively. Precision, accuracy, selectivity, stability, and robustness were some of the terms considered in validating the current RPLC method. Based on these results, a simple and reliable RPLC method was successfully applied to quantify BZDs in human plasma matrix appearing with recoveries ranging from 96.5 to 107.5% and interday RSD less than 4%. The current developed method was useful for rapidly screening the most commonly used BZDs in the market within their therapeutic concentration ranges. Full article
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15 pages, 2460 KiB  
Review
Role of Ionic Liquids in Capillary Electrophoresis
by Imran Ali, Mohammad Suhail, Marcello Locatelli, Salim Ali and Hassan Y. Aboul-Enein
Analytica 2022, 3(2), 236-250; https://doi.org/10.3390/analytica3020017 - 02 Jun 2022
Cited by 6 | Viewed by 2664
Abstract
Ionic liquids are a very important class of compounds due to their remarkable properties and wide range of applications. On the other hand, capillary electrophoresis is also gaining importance in separation science because of its fast speed and inexpensive nature. The use of [...] Read more.
Ionic liquids are a very important class of compounds due to their remarkable properties and wide range of applications. On the other hand, capillary electrophoresis is also gaining importance in separation science because of its fast speed and inexpensive nature. The use of ionic liquids in capillary electrophoresis is gaining importance continuously. The present review article describes the applications of ionic liquids in capillary electrophoresis. This article also describes the general aspects of ionic liquids and capillary electrophoresis. The use of ionic liquids in capillary electrophoresis, optimization of separation, mechanism of separation, and toxicity of ionic liquids, as well as their future perspectives, have also been discussed. It was observed that not much work has been performed in capillary electrophoresis using ionic liquids. It was also realized that the use of ionic liquids in capillary electrophoresis could revolutionize analytical science. Briefly, there is a great need for the use of ionic liquids in capillary electrophoresis for better and more effective separation. Full article
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8 pages, 858 KiB  
Article
In Vitro Antifungal Antibacterial Activity of Partitions from Euphorbia tirucalli L.
by Michel Stéphane Heya, María Julia Verde-Star, Sergio Arturo Galindo-Rodríguez, Catalina Rivas-Morales, Efrén Robledo-Leal and David Gilberto García-Hernández
Analytica 2022, 3(2), 228-235; https://doi.org/10.3390/analytica3020016 - 23 May 2022
Viewed by 3115
Abstract
We determined the antifungal and antimicrobial sensitivity of Euphorbia tirucalli extracts in vitro. Antifungal and antibacterial activity was determined based on the M38-A and M26-A protocols, respectively. The methanolic and ethanolic partitions demonstrated antidermatophytic activity against Trichophyton rubrum (MIC 125 µg/mL for ethanol [...] Read more.
We determined the antifungal and antimicrobial sensitivity of Euphorbia tirucalli extracts in vitro. Antifungal and antibacterial activity was determined based on the M38-A and M26-A protocols, respectively. The methanolic and ethanolic partitions demonstrated antidermatophytic activity against Trichophyton rubrum (MIC 125 µg/mL for ethanol and MIC 125 µg/mL for methanol) and T. interdigitalis (MIC 500 µg/mL for ethanol; 125 µg/mL for methanol). These partitions also showed antibacterial activity—the ethanolic partition had an MIC of 1.56 ± 0.02 mg/mL against methicillin-resistant Staphylococcus aureus (clinical isolate), 6.25 ± 0.04 mg/mL against Staphylococcus aureus BAA-44, 3.13 ± 0.13 mg/mL against Pseudomonas aeruginosa 27853, and 3.13 ± 0.15 mg/mL against Escherichia coli ATCC 25922; the methanolic partition showed an MIC of 1.56 ± 0.02 mg/mL against P. aeruginosa 27853 and 1.56 ± 0.043 mg/mL against E. coli ATCC 25922. These partitions show promise as antimicrobial agents or adjuvants in the treatment of infections caused by these microorganisms. Full article
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17 pages, 1540 KiB  
Article
Evaluation of Sweat-Sampling Procedures for Human Stress-Biomarker Detection
by Maria João Nunes, José J. G. Moura, João Paulo Noronha, Luís Cobra Branco, Alejandro Samhan-Arias, João P. Sousa, Carlos Rouco and Cristina M. Cordas
Analytica 2022, 3(2), 178-194; https://doi.org/10.3390/analytica3020013 - 16 Apr 2022
Cited by 4 | Viewed by 3811
Abstract
Sweat is a potential biological fluid for the non-invasive analytical assessment of diverse molecules, including biomarkers. Notwithstanding, the sampling methodology is critical, and it must be assessed prior to using sweat for clinical diagnosis. In the current work, the analytical methodology was further [...] Read more.
Sweat is a potential biological fluid for the non-invasive analytical assessment of diverse molecules, including biomarkers. Notwithstanding, the sampling methodology is critical, and it must be assessed prior to using sweat for clinical diagnosis. In the current work, the analytical methodology was further developed taking into account the sampling step, in view of the identification and level variations of sweat components that have potential to be stress biomarkers using separation by liquid chromatography and detection by tandem mass spectrometry, in order to attain a screening profile of 26 molecules in just one stage. As such, the molecule identification was used as a test for the evaluation of the sampling procedures, including the location on the body, using patches for long-term sampling and vials for direct sampling, through a qualitative approach. From this evaluation it was possible to conclude that the sampling may be performed on the chest or back skin. Additionally, possible interference was evaluated. The long-term sampling with patches can be used under both rest and exercise conditions with variation of the detected molecule’s levels. The direct sampling, using vials, has the advantage of not having interferences but the disadvantage of only being effective after exercise in order to have enough sample for sweat analysis. Full article
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17 pages, 1852 KiB  
Article
Development and Validation of an HPLC Method for the Determination of Meloxicam and Pantoprazole in a Combined Formulation
by Raneem Ahmad, Mohammad Hailat, Zainab Zakaraya, Osaid Al Meanazel and Wael Abu Dayyih
Analytica 2022, 3(2), 161-177; https://doi.org/10.3390/analytica3020012 - 01 Apr 2022
Cited by 2 | Viewed by 4117
Abstract
Nonsteroidal anti-inflammatory drugs are the most commonly prescribed anti-inflammatory drugs worldwide. The most common side effects are gastrointestinal. Pantoprazole, a proton pump inhibitor (PPI), can be used to prevent these events from occurring. In this study, we attempt to develop and validate a [...] Read more.
Nonsteroidal anti-inflammatory drugs are the most commonly prescribed anti-inflammatory drugs worldwide. The most common side effects are gastrointestinal. Pantoprazole, a proton pump inhibitor (PPI), can be used to prevent these events from occurring. In this study, we attempt to develop and validate a novel method for determining and validating the fixed-dose combination of meloxicam and pantoprazole. A new method has been developed and validated to estimate pantoprazole and meloxicam in a fixed-dose combination using RP-HPLC. In order to separate the drugs, a mobile phase phosphate buffer/acetate was used (30:70, v/v), with a pH of 3.4 and a flow rate of 1.0 mL/min at 25 °C. The detection wavelength for the drugs was at a wavelength of 310 nm. The retention times for meloxicam and pantoprazole were 6 and 9 min, respectively. In concentrations ranging from 0.1 to 200 mg/L, the linearity of the detector was established. The r was 0.9998 for both drugs. Recovery rates ranged from 98 to 102% on average. According to the guidelines of the International Council on Harmonization, the results were satisfactory. Using the method presented herein, the pharmaceutical formulation of the combined meloxicam and pantoprazole can be routinely tested. Full article
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14 pages, 3098 KiB  
Article
All-Step-in-One Test Kit for Paraquat Detection in Water and Vegetable Samples
by Chanakarn Sangsum and Phoonthawee Saetear
Analytica 2022, 3(1), 92-105; https://doi.org/10.3390/analytica3010007 - 23 Feb 2022
Cited by 1 | Viewed by 4613
Abstract
This work presents the first development of an all-steps-in-one test kit for the determination of paraquat in natural water, and vegetable and agricultural samples. A handheld photometer incorporated with a magnetic stirrer was used to complete the steps of extraction, mixing, and detection. [...] Read more.
This work presents the first development of an all-steps-in-one test kit for the determination of paraquat in natural water, and vegetable and agricultural samples. A handheld photometer incorporated with a magnetic stirrer was used to complete the steps of extraction, mixing, and detection. Paraquat produces a blue free radical ion via a reduction with sodium dithionite in alkaline conditions. Sodium dithionite powder was investigated for the enhancement of reagent stability duration, which was added directly into sample solution that showed insignificant difference in sensitivity as compared with that of the solution format of sodium dithionite. The developed test kit showed good performance with the linear calibration of 0.5 to 10 mg L−1 with a high coefficient of determination (r2 = 0.9947). The lower limit of quantitation (LLOQ = 3SD of intercept per slope) carried out from the method using the handheld photometer was 0.50 mg L−1. The limit of detection (LOD) by naked eye was 0.30 mg L−1. The recovery study was acceptable in the range of 101–115%. Intraday (n = 3) and interday (n = 3) precision was less than 1%. On the basis of the significance test at the 95% confidence interval, quantitative results of the developed test kit agreed well with those from high-performance liquid chromatography (HPLC). To the best of our knowledge, this is the first report demonstrating an online extraction for vegetables incorporated into a test kit, applicable for on-site analysis. Single-point calibration based on the Beer–Lambert law also demonstrated the measurement of paraquat. In testing with a nominal standard solution of 5.00 mg L−1 paraquat, the reading concentration was 5.09 ± 0.03 mg L−1 paraquat (n = 20) with a K value of 0.0967 (close to the slope of multipoint calibration). This research is a direct benefit to agricultural products and the health of a population for the analysis of pesticides and herbicides. Full article
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18 pages, 2727 KiB  
Article
Improved Enzymatic Assay and Inhibition Analysis of Redox Membranotropic Enzymes, AtGALDH and TcGAL, Using a Reversed Micellar System
by Andrey A. Chudin and Elena V. Kudryashova
Analytica 2022, 3(1), 36-53; https://doi.org/10.3390/analytica3010004 - 03 Feb 2022
Cited by 7 | Viewed by 3192
Abstract
Reversed micelles are helpful to solubilize otherwise insoluble membranotropic or membrane-bound enzymes in their functional form, thus enabling activity assay and inhibition analysis. However, in the case of redox enzymes, this task is further complicated by the necessity to select an appropriate electron-acceptor [...] Read more.
Reversed micelles are helpful to solubilize otherwise insoluble membranotropic or membrane-bound enzymes in their functional form, thus enabling activity assay and inhibition analysis. However, in the case of redox enzymes, this task is further complicated by the necessity to select an appropriate electron-acceptor (EA) which, ideally, should be compatible with spectrophotometric measurements in reversed micelles. Here, we have identified such an EA and successfully used it in a reversed micellar environment to assay the activity of two homologous enzymes from mitochondria: l-galactone-1,4-lactone dehydrogenase (EC 1.3.2.3) from Arabidopsis thaliana (AtGALDH) and galactonolactone oxidase (EC 1.3.3.12) from Trypanosoma cruzi (TcGAL), differing in their membranotropic properties, with TcGAL being almost insoluble in water and particularly difficult to assay. Furthermore, we have demonstrated the possibility to use this assay for inhibition analysis, with an elucidation of the mechanism and inhibition parameters, which otherwise could not be possible. In order to perform inhibition analysis, we improved the approach for the determination of activity of such membrane enzymes based on a reversed micellar system as membrane matrix, necessary for the functioning of membrane enzymes. A number of electron acceptors (EA) were tested for AtGALDH and optimal conditions of activity determination for AtGALDH were found. The suggested method was successfully applied to the study of the inhibition of AtGALDH by lycorine, and the mixed competitive mechanism of inhibition of AtGALDH by lycorine was determined. The developed approach to inhibitor analysis was applied for TcGAL, insoluble in water membrane, and the method provides new opportunities for searching effective inhibitors that may be potential drugs. Indeed, galactonolactone oxidase from Trypanosoma cruzi (TcGAL) and AtGALDH are homologues, and the inhibition of TcGAL stops the vital biosynthesis of vitamin C in parasite Trypanosoma cruzi from causing Chagas disease. The approach proposed can be applied for the screening of inhibitors of AtGALDH and TcGAL, as well as to study properties of other membrane enzymes including determination of the mechanisms of inhibition, structure and catalytic properties, the impact of membrane components (for example lipids), and so on. Full article
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10 pages, 1351 KiB  
Article
Simple Analytical Strategy for Screening Three Synthetic Cathinones (α-PVT, α-PVP, and MDPV) in Oral Fluids
by André M. Segurado, Samir M. Ahmad, Nuno R. Neng, Margarida M. Maniés-Sequeira, Helena Gaspar and José Manuel F. Nogueira
Analytica 2022, 3(1), 14-23; https://doi.org/10.3390/analytica3010002 - 01 Jan 2022
Cited by 1 | Viewed by 2999
Abstract
Synthetic cathinones are analogue compounds of the plant based stimulant cathinone. Its use, abuse, and related consumption complications have steadily increased in the last years. For this reason, there is a need for innovative analytical approaches that enable its rapid screening in biological [...] Read more.
Synthetic cathinones are analogue compounds of the plant based stimulant cathinone. Its use, abuse, and related consumption complications have steadily increased in the last years. For this reason, there is a need for innovative analytical approaches that enable its rapid screening in biological matrices (e.g., oral fluids). The present work proposes a new analytical methodology by combining bar adsorptive microextraction followed by microliquid desorption and gas chromatography coupled to mass spectrometry (BAµE-µLD/GC-MS) for screening three synthetic cathinones (α-PVP, α-PVT, and MDPV) in oral fluids. The optimization of the BAµE-µLD/GC-MS methodology was successfully applied for the analysis of the target compounds in oral fluids. The results show average recoveries between 43.1 and 52.3% for the three synthetic cathinones. Good selectivity was also noticed. The developed methodology presents itself as an alternative tool to screen these compounds in oral fluids. To the best of our knowledge, this is the first work that combines a microextraction sorption-based technique followed by GC-MS analysis for the screening of synthetic cathinones in oral fluids. Full article
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2021

Jump to: 2024, 2023, 2022, 2020

24 pages, 1813 KiB  
Review
Ion-Channel Antiepileptic Drugs: An Analytical Perspective on the Therapeutic Drug Monitoring (TDM) of Ezogabine, Lacosamide, and Zonisamide
by Roberto Mandrioli, Michele Protti, Lorenzo Marincich and Laura Mercolini
Analytica 2021, 2(4), 171-194; https://doi.org/10.3390/analytica2040016 - 30 Nov 2021
Cited by 2 | Viewed by 3943
Abstract
The term seizures includes a wide array of different disorders with variable etiology, which currently represent one of the most important classes of neurological illnesses. As a consequence, many different antiepileptic drugs (AEDs) are currently available, exploiting different activity mechanisms and providing different [...] Read more.
The term seizures includes a wide array of different disorders with variable etiology, which currently represent one of the most important classes of neurological illnesses. As a consequence, many different antiepileptic drugs (AEDs) are currently available, exploiting different activity mechanisms and providing different levels of performance in terms of selectivity, safety, and efficacy. AEDs are currently among the psychoactive drugs most frequently involved in therapeutic drug monitoring (TDM) practices. Thus, the plasma levels of AEDs and their metabolites are monitored and correlated to administered doses, therapeutic efficacy, side effects, and toxic effects. As for any analytical endeavour, the quality of plasma concentration data is only as good as the analytical method allows. In this review, the main techniques and methods are described, suitable for the TDM of three AEDs belonging to the class of ion channel agents: ezogabine (or retigabine), lacosamide, and zonisamide. In addition to this analytical overview, data are provided, pertaining to two of the most important use cases for the TDM of antiepileptics: drug–drug interactions and neuroprotection activity studies. This review contains 146 references. Full article
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15 pages, 3399 KiB  
Article
Quantification of PD-1/PD-L1 Interaction between Membranes from PBMCs and Melanoma Samples Using Cell Membrane Microarray and Time-Resolved Förster Resonance Energy Transfer
by Lissete Sánchez-Magraner, Miguel de la Fuente, Charles Evans, James Miles, Ane Elexpe, Maddalen Rodriguez-Astigarraga, Egoitz Astigarraga and Gabriel Barreda-Gómez
Analytica 2021, 2(4), 156-170; https://doi.org/10.3390/analytica2040015 - 13 Oct 2021
Cited by 9 | Viewed by 4251
Abstract
Melanoma is a carcinoma known to evade the host immune defenses via the downregulation of the immune response. One of the molecules involved in this mechanism is programmed cell death ligand 1 (PD-L1), which interacts with its receptor, programmed cell death protein 1 [...] Read more.
Melanoma is a carcinoma known to evade the host immune defenses via the downregulation of the immune response. One of the molecules involved in this mechanism is programmed cell death ligand 1 (PD-L1), which interacts with its receptor, programmed cell death protein 1 (PD-1), expressed on T cells, leading to a reduction in cytokine release and cytotoxic activity, as well as a halt in T-cell proliferation. The approved therapeutic monoclonal antibodies, such as pembrolizumab, target the PD-1/PD-L1 interaction and are revolutionizing cancer treatments. We developed an assay that provides a quantitative readout of PD-1/PD-L1 interactive states between cell membranes of human immune cells (peripheral blood mononuclear cells, PBMCs) and PD-L1-expressing samples. For this purpose, cell membrane microarrays (CMMAs) were developed from membranes isolated from a HT144 cell line and melanoma samples, and PD-L1 expression was quantified using immunofluorescence (IF). CMMAs were incubated with cell membranes of PBMCs expressing PD-1, and the interaction with PD-L1 was quantified by time-resolved Förster resonance energy transfer, in the presence and absence of pembrolizumab as a blocking drug. The developed assay was able to quantify the PD-1/PD-L1 interaction, and this engagement was disrupted in the presence of the blocking antibody. This demonstrates the potential of the method to analyze monoclonal antibody drugs, as well as the functional states of immune checkpoint regulators. Furthermore, our findings provide evidence to support the future implementation of this methodology for both drug discovery and immune system monitoring in cancer, transplantation, and inflammatory and autoimmune diseases. Full article
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16 pages, 2840 KiB  
Article
Evaluating the Performance of 193 nm Ultraviolet Photodissociation for Tandem Mass Tag Labeled Peptides
by Mowei Zhou, Ju Yeon Lee, Gun Wook Park, Neha Malhan, Tao Liu and Jared B. Shaw
Analytica 2021, 2(4), 140-155; https://doi.org/10.3390/analytica2040014 - 09 Oct 2021
Cited by 3 | Viewed by 2781
Abstract
Despite the successful application of tandem mass tags (TMT) for peptide quantitation, missing reporter ions in higher energy collisional dissociation (HCD) spectra remains a challenge for consistent quantitation, especially for peptides with labile post-translational modifications. Ultraviolet photodissociation (UVPD) is an alternative ion activation [...] Read more.
Despite the successful application of tandem mass tags (TMT) for peptide quantitation, missing reporter ions in higher energy collisional dissociation (HCD) spectra remains a challenge for consistent quantitation, especially for peptides with labile post-translational modifications. Ultraviolet photodissociation (UVPD) is an alternative ion activation method shown to provide superior coverage for sequencing of peptides and intact proteins. Here, we optimized and evaluated 193 nm UVPD for the characterization of TMT-labeled model peptides, HeLa proteome, and N-glycopeptides from model proteins. UVPD yielded the same TMT reporter ions as HCD, at m/z 126–131. Additionally, UVPD produced a wide range of fragments that yielded more complete characterization of glycopeptides and less frequent missing TMT reporter ion channels, whereas HCD yielded a strong tradeoff between characterization and quantitation of TMT-labeled glycopeptides. However, the lower fragmentation efficiency of UVPD yielded fewer peptide identifications than HCD. Overall, 193 nm UVPD is a valuable tool that provides an alternative to HCD for the quantitation of large and highly modified peptides with labile PTMs. Continued development of instrumentation specific to UVPD will yield greater fragmentation efficiency and fulfil the potential of UVPD to be an all-in-one spectrum ion activation method for broad use in the field of proteomics. Full article
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10 pages, 1042 KiB  
Article
Simultaneous Detection of Drug-Induced Liver Injury Protein and microRNA Biomarkers Using Dynamic Chemical Labelling on a Luminex MAGPIX System
by Antonio Marín-Romero, Mavys Tabraue-Chávez, Bárbara López-Longarela, Mario A. Fara, Rosario M. Sánchez-Martín, James W. Dear, Hugh Ilyine, Juan J. Díaz-Mochón and Salvatore Pernagallo
Analytica 2021, 2(4), 130-139; https://doi.org/10.3390/analytica2040013 - 03 Oct 2021
Cited by 7 | Viewed by 3168
Abstract
Drug-induced liver injury (DILI) is a potentially fatal adverse event and a leading cause for pre- and post-marketing drug withdrawal. Several multinational DILI initiatives have now recommended a panel of protein and microRNA (miRNA) biomarkers that can detect early liver injury and inform [...] Read more.
Drug-induced liver injury (DILI) is a potentially fatal adverse event and a leading cause for pre- and post-marketing drug withdrawal. Several multinational DILI initiatives have now recommended a panel of protein and microRNA (miRNA) biomarkers that can detect early liver injury and inform about mechanistic basis. This manuscript describes the development of seqCOMBO, a unique combo-multiplexed assay which combines the dynamic chemical labelling approach and an antibody-dependant method on the Luminex MAGPIX system. SeqCOMBO enables a versatile multiplexing platform to perform qualitative and quantitative analysis of proteins and miRNAs in patient serum samples simultaneously. To the best of our knowledge, this is the first method to profile protein and miRNA biomarkers to diagnose DILI in a single-step assay. Full article
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28 pages, 2878 KiB  
Review
Current Methods for the Extraction and Analysis of Isothiocyanates and Indoles in Cruciferous Vegetables
by Sofia Karanikolopoulou, Panagiota-Kyriaki Revelou, Marinos Xagoraris, Maroula G. Kokotou and Violetta Constantinou-Kokotou
Analytica 2021, 2(4), 93-120; https://doi.org/10.3390/analytica2040011 - 24 Sep 2021
Cited by 8 | Viewed by 6941
Abstract
Cruciferous vegetables are characterized by the presence of sulfur-containing secondary plant metabolites known as glucosinolates (GLS). The consumption of cruciferous vegetables such as broccoli, cabbage, rocket salad, and cauliflower has been related to the prevention of non-communicable diseases. Their beneficial effects are attributed [...] Read more.
Cruciferous vegetables are characterized by the presence of sulfur-containing secondary plant metabolites known as glucosinolates (GLS). The consumption of cruciferous vegetables such as broccoli, cabbage, rocket salad, and cauliflower has been related to the prevention of non-communicable diseases. Their beneficial effects are attributed to the enzymatic degradation products of GLS, e.g., isothiocyanates and indoles. Owing to these properties, there has been a shift in the last few years towards the research of these compounds and a wide range of methods for their extraction and analytical determination have been developed. The aim of this review is to present the sample preparation and extraction procedures of isothiocyanates and indoles from cruciferous vegetables and the analytical methods for their determination. The majority of the references that have been reviewed are from the last decade. Although efforts towards the application of eco-friendly non-conventional extraction methods have been made, the use of conventional solvent extraction is mainly applied. The major analytical techniques employed for the qualitative and quantitative analysis of isothiocyanates and indoles are high-performance liquid chromatography and gas chromatography coupled with or without mass spectrometry detection. Nevertheless, the analytical determination of isothiocyanates presents several problems due to their instability and the absence of chromophores, making the simultaneous determination of isothiocyanates and indoles a challenging task. Full article
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1 pages, 150 KiB  
Editorial
Analytical Chemistry and Innovative Applications
by Marcello Locatelli
Analytica 2021, 2(2), 37; https://doi.org/10.3390/analytica2020004 - 29 Apr 2021
Viewed by 2727
Abstract
In this issue of the Journal “Analytica”, there is a selection of accepted articles, after peer-review process, in which the great importance that Analytical Chemistry plays in the field of Applied Sciences and the vastness of the implications in the various sectors are [...] Read more.
In this issue of the Journal “Analytica”, there is a selection of accepted articles, after peer-review process, in which the great importance that Analytical Chemistry plays in the field of Applied Sciences and the vastness of the implications in the various sectors are highlighted [...] Full article
12 pages, 8407 KiB  
Article
Analysis of Acetylcholinesterase Activity in Cell Membrane Microarrays of Brain Areas as a Screening Tool to Identify Tissue Specific Inhibitors
by Bárbara Rienda, Ane Elexpe, Tarson Tolentino-Cortez, Marina Gulak, Cristina Bruzos-Cidón, María Torrecilla, Egoitz Astigarraga and Gabriel Barreda-Gómez
Analytica 2021, 2(1), 25-36; https://doi.org/10.3390/analytica2010003 - 23 Mar 2021
Cited by 17 | Viewed by 5452
Abstract
Acetylcholinesterase (AChE) is responsible for hydrolyzing the acetylcholine neurotransmitter, bringing an end point to cholinergic neurotransmission. Thus, AChE is the primary target of a wide spectrum of compounds used as pesticides, nerve agents or therapeutic drugs for neurodegenerative diseases such as Alzheimer’s disease [...] Read more.
Acetylcholinesterase (AChE) is responsible for hydrolyzing the acetylcholine neurotransmitter, bringing an end point to cholinergic neurotransmission. Thus, AChE is the primary target of a wide spectrum of compounds used as pesticides, nerve agents or therapeutic drugs for neurodegenerative diseases such as Alzheimer’s disease (AD). This enzyme is heterogeneously distributed in the brain showing different activity depending on the nervous region. Therefore, the aim of this work is to report a novel technology that enables the simultaneous determination of tissue specific AChE activity, as well as the analysis and screening of specific inhibitors, by using cell membrane microarrays. These microarrays were composed of cell membranes, isolated from 41 tissues, organs and brain areas, that were immobilized over a slide, maintaining the functionality of membrane proteins. To validate this platform, demonstrating its usefulness in drug discovery as a high throughput screening tool, a colorimetric protocol to detect the membrane-bound AChE activity was optimized. Thus, rat cortical and striatal AChE activities were estimated in presence of increased concentrations of AChE inhibitors, and the donepezil effect was assessed simultaneously in 41 tissues and organs, demonstrating the major potential of this microarray’s technology. Full article
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13 pages, 995 KiB  
Article
Detection of Sub-Aroma Threshold Concentrations of Wine Methoxypyrazines by Multidimensional GCMS
by Kenneth J. Olejar, Jason Breitmeyer, Pradeep M. Wimalasiri, Bin Tian and Stewart K. Field
Analytica 2021, 2(1), 1-13; https://doi.org/10.3390/analytica2010001 - 02 Jan 2021
Cited by 5 | Viewed by 4665
Abstract
Complex matrices, such as wine, provide a challenge in the quantification of compounds. There exists a high likelihood of co-elution in these matrices, thereby artificially increasing the observed concentration. This can often lead to confusing data where compounds are above aroma detection thresholds, [...] Read more.
Complex matrices, such as wine, provide a challenge in the quantification of compounds. There exists a high likelihood of co-elution in these matrices, thereby artificially increasing the observed concentration. This can often lead to confusing data where compounds are above aroma detection thresholds, but are not detected by olfactory analysis. Additionally, the lack of sensitivity in assays can lead to the non-detection of sub-aroma threshold concentrations and contrasting data when olfactory analysis detects these aromas. To eliminate these pitfalls and gain a better understanding of the role that methoxypyrazines impart green character to wine, a quantitative method using headspace solid-phase microextraction coupled to heart-cutting multidimensional gas chromatography mass spectrometry was developed. The method can quantitate the three common methoxypyrazines found in wine at the picogram per liter level while resolving co-eluting compounds. The proposed method was validated using model wine and wine solutions and was ultimately used for the comparative analysis of white, rosé, and red wines. Full article
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2020

Jump to: 2024, 2023, 2022, 2021

16 pages, 1213 KiB  
Review
Analytical Chemistry in the 21st Century: Challenges, Solutions, and Future Perspectives of Complex Matrices Quantitative Analyses in Biological/Clinical Field
by Giuseppe Maria Merone, Angela Tartaglia, Marcello Locatelli, Cristian D’Ovidio, Enrica Rosato, Ugo de Grazia, Francesco Santavenere, Sandra Rossi and Fabio Savini
Analytica 2020, 1(1), 44-59; https://doi.org/10.3390/analytica1010006 - 30 Oct 2020
Cited by 13 | Viewed by 7314
Abstract
Nowadays, the challenges in analytical chemistry, and mostly in quantitative analysis, include the development and validation of new materials, strategies and procedures to meet the growing need for rapid, sensitive, selective and green methods. In this context, considering the constantly updated International Guidelines, [...] Read more.
Nowadays, the challenges in analytical chemistry, and mostly in quantitative analysis, include the development and validation of new materials, strategies and procedures to meet the growing need for rapid, sensitive, selective and green methods. In this context, considering the constantly updated International Guidelines, constant innovation is mandatory both in the pre-treatment procedures and in the instrumental configurations to obtain reliable, true, and reproducible information. In this context, additionally to the classic plasma (or serum) matrices, biopsies, whole blood, and urine have seen an increase in the works that also consider non-conventional matrices. Obviously, all these studies have shown that there is a correlation between the blood levels and those found in the new matrix, in order to be able to correlate and compare the results in a robust way and reduce any bias problems. This review provides an update of the most recent developments currently in use in the sample pre-treatment and instrument configurations in the biological/clinical fields. Furthermore, the review concludes with a series of considerations regarding the role and future developments of Analytical Chemistry in light of the forthcoming challenges and new goals to be achieved. Full article
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11 pages, 1644 KiB  
Article
Filling Gaps on Stability Data: Development, Validation and Application of a Multianalyte UHPLC-DAD Method to Determine the Stability of Commonly Administered Drugs in Different Carrier Solutions Used in Palliative Care
by Christian Steuer, Ursina Müller, Fiona Haller and Peter Wiedemeier
Analytica 2020, 1(1), 33-43; https://doi.org/10.3390/analytica1010005 - 13 Oct 2020
Cited by 2 | Viewed by 4682
Abstract
In palliative care, continuous subcutaneous infusion (CSCI) is common practice for drug administration when oral application of drugs is not feasible or not reliable anymore. However, use of CSCI is limited to chemical stability of drugs and their combination in carrier solution. To [...] Read more.
In palliative care, continuous subcutaneous infusion (CSCI) is common practice for drug administration when oral application of drugs is not feasible or not reliable anymore. However, use of CSCI is limited to chemical stability of drugs and their combination in carrier solution. To determine the stability of different mixtures of commonly used drugs in palliative care, a multi-analyte UHPLC-DAD method controlled by an internal standard was successfully developed. The method was validated in terms of specificity, accuracy, precision, and linearity across the calibration range. Seven analytes could be separated within 10 min by C18-reversed phase chromatography. The method was successfully applied to close gaps in stability data and complete missing data for decision makers in health care units. Our results indicated the stability of binary mixtures and one ternary mixture in 0.9% saline and 5% glucose as carrier solutions. The obtained data will support pharmacists in palliative care for the preparation of parenteral drug solutions in the future. Full article
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10 pages, 1524 KiB  
Article
Statistical Optimization of Urinary Organic Acids Analysis by a Multi-Factorial Design of Experiment
by Marco Pazzi, Sara Colella, Eugenio Alladio, M. Paola Puccinelli, Giulio Mengozzi and Claudio Medana
Analytica 2020, 1(1), 14-23; https://doi.org/10.3390/analytica1010003 - 28 Aug 2020
Cited by 4 | Viewed by 4687
Abstract
The analysis of urinary organic acids is useful for patients suspected to have inborn errors of metabolism known as organic acidurias. These diseases cause an accumulation of organic acids in body fluids and their abnormal excretion in urines. By means of chemometrics tools, [...] Read more.
The analysis of urinary organic acids is useful for patients suspected to have inborn errors of metabolism known as organic acidurias. These diseases cause an accumulation of organic acids in body fluids and their abnormal excretion in urines. By means of chemometrics tools, such as principal component analysis and multiple linear regression, it was concluded that the conditions used in our laboratory are really the most suitable to achieve high yields of analytes. Full article
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