Novel Applications of Separation Technology

A special issue of Separations (ISSN 2297-8739). This special issue belongs to the section "Chromatographic Separations".

Deadline for manuscript submissions: 10 June 2024 | Viewed by 41997

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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
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Guest Editor
Department of Chemistry, Aristotle University, 54124 Thessaloniki, Greece
Interests: hyphenated techniques and mass spectrometry; atomic spectrometry techniques; speciation analysis; sample pretreatment techniques; chemometrics
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue, “Novel Applications of Separation Technology”, is focused on various applications that are based on separation technologies. These can include the following: analytical chemistry–quality control, inorganic–bioinorganic chemistry–nanotechnology, archaeometry–maintenance and restoration of cultural monuments, biochemistry–clinical chemistry, chemical education and teaching, organic chemistry–natural products, physical–theoretical and computational chemistry, toxicology–medicinal chemistry, environmental chemistry and technology–pollution control, polymer chemistry and technology, food chemistry and technology, and chemical technology–materials–green chemistry; however, of course, the list is not limited to the abovementioned areas. It can be expanded with new scientific fields in chemistry and related science, or science that is using the tools that chemistry provides in order to advance their research outcomes.

Prof. Dr. Victoria Samanidou
Prof. Dr. George Zachariadis
Guest Editors

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Keywords

  • chemistry
  • analytical chemistry
  • separation technologies
  • separation science
  • chromatography
  • applications

Published Papers (19 papers)

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10 pages, 1496 KiB  
Article
Isolation and Chemotaxonomic Implications of Tenelloside, a Novel Unusual C-Glycosyl Flavanone from Phyllanthus tenellus Roxb. in Tenerife Island
by Antonio Francioso, Ignacio Antonio Jiménez Díaz, Carolina Pérez Reyes, Cristina González Montelongo, Marco Pierini, Claudio Villani and Isabel López Bazzocchi
Separations 2024, 11(1), 15; https://doi.org/10.3390/separations11010015 - 31 Dec 2023
Viewed by 1520
Abstract
Phyllanthus is a large genus of the Euphorbiaceae family, which has been widely used in traditional medicine. The current study reports the isolation of an unusual C-glycosyl flavonoid, named tenelloside, from Phyllanthus tenellus Roxb., a non-endemic plant present in Canary Islands. The [...] Read more.
Phyllanthus is a large genus of the Euphorbiaceae family, which has been widely used in traditional medicine. The current study reports the isolation of an unusual C-glycosyl flavonoid, named tenelloside, from Phyllanthus tenellus Roxb., a non-endemic plant present in Canary Islands. The chemical structure of this secondary metabolite was established employing combined spectrometric and spectroscopic techniques, including 1D and 2D NMR experiments and mass spectrometry. The absolute stereochemical configuration was determined via the comparison of experimental and calculated electronic circular dichroism spectra. In our previous work, another C-glycosylated bioactive product was isolated from another Phyllanthus species, suggesting that this class of compounds can be produced in a genus-specific manner in different geographic regions. This work represents another important report for direct future studies on the biological and chemotaxonomic potential of C-glycosylated products of the Phyllanthus genus. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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15 pages, 2281 KiB  
Article
Determination of the Relationship between the Granulometry and Release of Polyphenols Using LC-UV, and Their Antioxidant Activity of the Pulp Powder of the Moroccan Argan Tree, “Argania spinosa L.”
by Ayoub Mourjane, Hafida Hanine, El Mustapha El Adnany, Mourad Ouhammou, Khalid Bitar, Mostafa Mahrouz and Ahcene Boumendjel
Separations 2023, 10(10), 542; https://doi.org/10.3390/separations10100542 - 16 Oct 2023
Viewed by 1498
Abstract
The bioavailability of cosmetic, pharmaceutical, nutraceutical, and food preparations depends, among other factors, on the galenic form and the control of the granulometric structure of powders. The present study aimed to evaluate the effect of argan pulp powder particle size on functional, physicochemical [...] Read more.
The bioavailability of cosmetic, pharmaceutical, nutraceutical, and food preparations depends, among other factors, on the galenic form and the control of the granulometric structure of powders. The present study aimed to evaluate the effect of argan pulp powder particle size on functional, physicochemical properties, and antioxidant bioactivity. The particle size study revealed a unimodal particle volume distribution, explaining the regular particle shape. The results relating to functional properties indicated that the critical fraction was in the range of 50–125 µm. However, the study of the particles in each class, evaluated via SEM, showed that the morphology of the pulp powder was strongly dependent on the degree of grinding. The classes in the range of 50–125 µm had the highest polyphenol content, while those of <25 µm had the highest flavonoid content (893.33 mg GAE/100 g DW and 128.67 mg CE/100 g DW, respectively). Molecular analysis via LC and GC-MS showed that particle size had a significant effect on the release of bioactive molecules. ABTS, DPPH, and TAC tests showed that the fraction, ‘‘50–125 µm’’, had the highest antioxidant activity. However, the FRAP test showed highest antioxidant activity for particles of <25 µm. The analysis of the bioactive compounds of the argan pulp powder confirmed a differential distribution, depending on the size of the particles. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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11 pages, 1267 KiB  
Article
Determination of Lysergic Acid Diethylamide and 2-Oxo-3-Hydroxy-LSD in Blood: Validation and Comparison of Two Liquid Chromatography–Tandem Mass Spectrometry Methods
by Alexandra Dimitrova, Maria Grazia Di Milia, Regina Rensi, Simone Grassi, Barbara Gualco and Fabio Vaiano
Separations 2023, 10(9), 502; https://doi.org/10.3390/separations10090502 - 14 Sep 2023
Cited by 1 | Viewed by 1776
Abstract
Lysergic acid diethylamide (LSD) is a powerful hallucinogen. Its detection is limited by its low dosage; moreover, LSD is rapidly metabolized into 2-oxo-3-hydroxy-LSD (O-H-LSD). In this study we validated two methods for determination of LSD and O-H-LSD in blood. Method #1 consisted in [...] Read more.
Lysergic acid diethylamide (LSD) is a powerful hallucinogen. Its detection is limited by its low dosage; moreover, LSD is rapidly metabolized into 2-oxo-3-hydroxy-LSD (O-H-LSD). In this study we validated two methods for determination of LSD and O-H-LSD in blood. Method #1 consisted in the upgrade of a previously developed procedure for detection of 163 compounds. Method #2 was specific for LSD and O-H-LSD. Analyses were performed through LC-MS/MS by dynamic (#1) and/or MRM mode (#2), in positive ionization. Transitions were: 324→223,208 m/z for LSD; 356→237,222 m/z for O-H-LSD. Validations were performed following the AAFS’s guidelines. Linearity was good for both methods. Sensitivity was in line with previously validated methods with LOQs at 0.0375 (#1) and 0.025 (#2) ng/mL for LSD and 0.01875 (#1) and 0.0125 (#2) ng/mL for O-H-LSD. Bias and %CV always met the acceptance criteria. RRs were >83%, except for O-H-LSD with method #1. The methods were successfully applied to two real cases. Method #1 proved to be useful for screening purposes, while method #2 can represent a sensitive and reliable tool for confirmation procedures. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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19 pages, 5711 KiB  
Article
Carob Pulp Flour Extract Obtained by a Microwave-Assisted Extraction Technique: A Prospective Antioxidant and Antimicrobial Agent
by Jana Zahorec, Dragana Šoronja-Simović, Sunčica Kocić-Tanackov, Sandra Bulut, Nikola Martić, Katarina Bijelić, Danica Božović and Branimir Pavlić
Separations 2023, 10(9), 465; https://doi.org/10.3390/separations10090465 - 24 Aug 2023
Viewed by 1052
Abstract
In this study, carob pulp flour (CF) extract was characterized as a high-value antioxidant and antimicrobial agent. CF extracts were obtained using microwave-assisted extraction (MAE) and optimization of the MAE process was accomplished using response surface methodology. The studied processing parameters of MAE [...] Read more.
In this study, carob pulp flour (CF) extract was characterized as a high-value antioxidant and antimicrobial agent. CF extracts were obtained using microwave-assisted extraction (MAE) and optimization of the MAE process was accomplished using response surface methodology. The studied processing parameters of MAE were the liquid/solid (L/S) ratio (10–30 mL/g), extraction time (15–35 min), and ethanol concentration (40–80% w/w). The efficiency of the extraction of valuable compounds from CF was evaluated by the determining extraction yield (Y), total phenolic(TP), total flavonoid (TF) content, and antioxidant activity (DPPH, FRAP, and ABTS). The optimized MAE parameters for maximizing the yields of target compounds and antioxidant activity were the L/S ratio 30 mL/g, extraction time 35 min, and ethanol concentration 40%. The experimentally obtained values for TP, TF, DPPH, FRAP, and ABTS were 1609.92 GAE/100 g, 271.92 CE/100 g, 99.02 µMTE/g, 50.45 µM Fe2+/g, and 110.55 µMTE/g, respectively. The optimized CF extract was compared with the CF extracts obtained by conventional solid–liquid extraction (S/L) and ultrasound-assisted extraction (UAE) and was found to be more beneficial due to a 30% higher yield of TP and TF and 30–80% higher antioxidant activity. The phenolic profiles of the three extracts were quite similar. The microdilution method confirmed the antibacterial activity of MAE and S/L extracts while the antifungal effect was not observed. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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10 pages, 629 KiB  
Article
Exploring the Chemical Composition and Antioxidant Properties of Apricot Kernel Oil
by Ioannis Makrygiannis, Vassilis Athanasiadis, Theodoros Chatzimitakos, Eleni Bozinou, Christiana Mantzourani, Arhontoula Chatzilazarou, Dimitris P. Makris and Stavros I. Lalas
Separations 2023, 10(6), 332; https://doi.org/10.3390/separations10060332 - 26 May 2023
Cited by 5 | Viewed by 2171
Abstract
Apricot kernels are known to be rich in bioactive compounds such as polyphenols, which have applications in various fields such as cosmetology and the food industry. However, the extraction of these compounds has not been extensively studied. In this study, we aimed to [...] Read more.
Apricot kernels are known to be rich in bioactive compounds such as polyphenols, which have applications in various fields such as cosmetology and the food industry. However, the extraction of these compounds has not been extensively studied. In this study, we aimed to extract oil from apricot kernels and investigate its composition and antioxidant properties. Samples from two years of apricot cannery by-products were used in the study. We employed a common extraction procedure using hexane as a solvent, followed by an analysis of the oil’s fatty acid composition and determination of its antioxidant properties using several methods. Our results indicated that the oil extracted from apricot kernels is rich in oleic and palmitoleic acids, which exhibit health benefits. As regards the volatile compounds of the oil, 2-methyl propanal, benzaldehyde, and benzyl alcohol were detected as the main compounds. Benzaldehyde was also found to be the main component of the essential oil of the kernel. Furthermore, the oil exhibited low antioxidant activity, as demonstrated by its ability to scavenge free radicals. Overall, our findings suggest that apricot kernels are a valuable source of oil with potential applications in the food and cosmetic industries. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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19 pages, 6519 KiB  
Article
Cellulose Paper Sorptive Extraction (CPSE) Combined with Gas Chromatography–Mass Spectrometry (GC–MS) for Facile Determination of Lorazepam Residues in Food Samples Involved in Drug Facilitated Crimes
by Bharti Jain, Rajeev Jain, Abuzar Kabir, Abhishek Ghosh, Torki Zughaibi, Vimukti Chauhan, Sonali Koundal and Shweta Sharma
Separations 2023, 10(5), 281; https://doi.org/10.3390/separations10050281 - 25 Apr 2023
Cited by 7 | Viewed by 1792
Abstract
Reports related to incidences of drug facilitated crimes (DFCs) have notably increased in recently. In such cases, victims report being assaulted or robbed while under the influence of drugs. Lorazepam (LZ) is frequently used in DFCs as it can easily make victims docile [...] Read more.
Reports related to incidences of drug facilitated crimes (DFCs) have notably increased in recently. In such cases, victims report being assaulted or robbed while under the influence of drugs. Lorazepam (LZ) is frequently used in DFCs as it can easily make victims docile owing to its potent numbing effect. Therefore, a straightforward and green analytical method to analyze LZ in spiked food matrices in connection with criminal acts becomes important. The current study reports a simple, green, and high sample throughput analytical method for determining LZ in food and drink matrices commonly encountered in DFCs, based on recently introduced cellulose paper sorptive extraction (CPSE). For the extraction of LZ from food matrices, pristine cellulose paper (CP, commonly used laboratory filter paper) was used as a sorptive medium. Five pieces of CP (1.5″ × 1.5″ each) were dipped into diluted food matrices (cream biscuits and tea) and stirred on a rotary shaker for 30 min at 200 rpm. The CPs were then dried, and the adsorbed LZ was back-extracted into 2 mL of methanol. The extract was then subjected to GC–MS analysis in selected ion monitoring (SIM) mode. Several parameters, including CP size and number, back-extraction solvent type and volume, sample volume, extraction time and stirring speed, pH, ionic strength, elution time and speed, were thoroughly screened and optimized. Under the optimized conditions, the method was found to be linear in the range of 0.2–10 µg·mL−1 (or µg·g−1) with a coefficient of determination (R2) ranging from 0.996–0.998. The limit of detection and limit of quantification for cream biscuits were 0.054 and 0.18 µg·g−1 whereas they were 0.05 and 0.16 µg·mL−1 for tea samples. For all measurements, the relative standard deviations (%RSD) were always below 10%. Two mL of methanol per sample was used during the entire sample preparation process. The greenness of the proposed procedure was evaluated using Analytical Eco-Scale and GAPI greenness assessment tools. Finally, the CPSE–GC–MS method has been applied for the determination of LZ in forensic food samples which were used in DFCs. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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15 pages, 1865 KiB  
Article
Development and Validation of a Confirmatory Method for the Determination of 12 Coccidiostat Residues in Eggs and Muscle by Means of Liquid Chromatography Coupled to Hybrid High Resolution Mass Spectrometry
by Federica Castellani, Matteo Ricci, Maria Novella Colagrande, Giampiero Scortichini and Giorgio Saluti
Separations 2023, 10(3), 202; https://doi.org/10.3390/separations10030202 - 14 Mar 2023
Cited by 5 | Viewed by 1682
Abstract
A confirmatory, highly selective multi-residue method based on liquid chromatography coupled to hybrid high resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated for the determination of 12 regulated coccidiostats in eggs and muscle. Particularly, ionophore antibiotics (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) [...] Read more.
A confirmatory, highly selective multi-residue method based on liquid chromatography coupled to hybrid high resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated for the determination of 12 regulated coccidiostats in eggs and muscle. Particularly, ionophore antibiotics (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) and synthetic coccidiostats (diclazuril, halofuginone, nicarbazin as 4,4′-dinitrocarbanilide fraction, robenidine and toltrazuril as toltrazuril-sulphone) were included in the method. The sample preparation consisted in the extraction of the analytes from the matrix with acetonitrile, followed by a clean-up step with Oasis® PRiME HLB SPE and a defatting procedure with n-hexane. Validation was successfully performed according to Commission Implementing Regulation (EU) 2021/808, starting from 1 µg kg−1. The procedure was verified through the analysis of a certified reference material (CRM) and the occurrence of the residues was assessed in the context of the Italian National Residue Control Plan (NRCP). Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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15 pages, 1714 KiB  
Article
Surfactant-Enhanced Extraction of Lutein from Marigold Petals using an Aqueous Two-Phase System
by Neha Maheshwari, Raj Kumar Arya, George D. Verros, Pradip B. Dhamole and Ashwin Kannan
Separations 2023, 10(2), 133; https://doi.org/10.3390/separations10020133 - 15 Feb 2023
Cited by 5 | Viewed by 3107
Abstract
The extraction of lutein from marigold petals using a surfactant-based aqueous two-phase system is reported. In this work, the effectiveness of the hydrophilic-lipophilic balance of surfactants on extraction performance for the extraction of lutein from marigold petal powder was demonstrated using aqueous solutions [...] Read more.
The extraction of lutein from marigold petals using a surfactant-based aqueous two-phase system is reported. In this work, the effectiveness of the hydrophilic-lipophilic balance of surfactants on extraction performance for the extraction of lutein from marigold petal powder was demonstrated using aqueous solutions of a wide range of non-ionic surfactants. The response surface methodology was applied to obtain optimised conditions for maximum extraction of lutein. At the optimised conditions (Temperature = 37.5 °C, S/L = 0.00375, and surfactant amount = 1.5% (v/v)), 12.12 ± 0.16 mg/g of lutein was obtained. Furthermore, the surface morphology of marigold petal powder (MPP) was analysed using SEM micrographs. Significant changes in surface morphology were observed which suggested better access of surfactant solution to the targeted biomolecule implanted in the matrix. Finally, the antioxidant activity of the obtained lutein extract was analysed using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Results suggest that the antioxidant activity of the lutein extract obtained by the surfactant-based system is more than that of the lutein extract obtained by organic solvents. The aforementioned results suggest that the lutein can be extracted using a surfactant-based aqueous two-phase system (ATPS). Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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30 pages, 12528 KiB  
Article
Preparation of Tryptanthrin Derivates Bearing a Thiosemicarbazone Moiety to Inhibit SARS-CoV-2 Replication
by Kateřina Veselá, Zora Mělková, Nikita Abramenko, Zdeněk Kejík, Robert Kaplánek, Petr Dytrych, Alla Sinica, Oleksandra Vozniuk, Pavel Martásek and Milan Jakubek
Separations 2023, 10(2), 73; https://doi.org/10.3390/separations10020073 - 20 Jan 2023
Viewed by 1858
Abstract
SARS-CoV-2 is a serious viral pathogen, and agents that inhibit its replication are in high demand. In the present work, we prepared two novel tryptanthrin derivates bearing a thiosemicarbazone moiety as potential antiviral agents. Both compounds displayed potent chelation activity against Fe(III/II) ion-associated [...] Read more.
SARS-CoV-2 is a serious viral pathogen, and agents that inhibit its replication are in high demand. In the present work, we prepared two novel tryptanthrin derivates bearing a thiosemicarbazone moiety as potential antiviral agents. Both compounds displayed potent chelation activity against Fe(III/II) ion-associated COVID-19. The molecular docking results suggest that the compounds can display significant affinity towards SARS-CoV-2 papain-like proteases and SARS-CoV-2 main proteases. In addition, administering T8H-TSC can repress viral replication in the used model (Vero cells). Moreover, the therapeutic potential of the prepared compounds was predicted and analysed in terms of Lipinski’s rules, drug-likeness and drug score. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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16 pages, 4682 KiB  
Article
Dimethyl Carbonate as a Mobile-Phase Modifier for Normal-Phase and Hydrophilic Interaction Liquid Chromatography
by Philip D. Boes, Sophie R. Elleman and Neil D. Danielson
Separations 2023, 10(2), 70; https://doi.org/10.3390/separations10020070 - 18 Jan 2023
Cited by 5 | Viewed by 2177
Abstract
We studied the use of dimethyl carbonate (DMC) as a non-toxic, aprotic modifier for hydrophilic liquid interaction chromatography (HILIC) and as a modifier for normal-phase liquid chromatography (LC). A comparison of ethyl acetate (EA) and DMC as organic mobile-phase modifiers in hexane for [...] Read more.
We studied the use of dimethyl carbonate (DMC) as a non-toxic, aprotic modifier for hydrophilic liquid interaction chromatography (HILIC) and as a modifier for normal-phase liquid chromatography (LC). A comparison of ethyl acetate (EA) and DMC as organic mobile-phase modifiers in hexane for normal-phase LC of phthalates was conducted with a silica column and showed that retention factors (k) at the same modifier percentage were about a factor of two greater for DMC. Detection at 215 nm, possible with DMC, allowed for the better detection of the phthalates by a factor of 10, compared with EA detection, best at a 254 nm wavelength. Using a core-shell silica column, HILIC separations of trans-ferulic acid, syringic acid, and vanillic acid were compared between acetonitrile (MeCN) and DMC as the organic portion of the mobile phase, from 80–95%. The analyte retention for DMC, when compared to MeCN, was about 1.5 times greater, with only a moderate increase in back pressure. Plate count and peak asymmetry were somewhat better for the DMC chromatograms, compared to those with MeCN. Seven mono- and di-hydroxybenzoic acid positional isomers could be resolved effectively with DMC. Sorbate and benzoate preservatives in commercial drinks were also determined. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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9 pages, 665 KiB  
Article
Development of Analytical Methods for the Determination of N-Bromosuccinimide in Different Active Pharmaceutical Ingredients by High-Performance Ion Chromatography with Suppressed Conductivity Detection
by Boglárka Páll, Imre Kapui, Róbert Kormány and Krisztián Horváth
Separations 2023, 10(1), 15; https://doi.org/10.3390/separations10010015 - 28 Dec 2022
Viewed by 2612
Abstract
Product safety is important for medicines. For drugs on the market, it must be demonstrated that the levels of toxic contaminants are below the permitted limits. These impurities are used as reagents or are generated during synthesis. N-bromosuccinimide is used as a brominating [...] Read more.
Product safety is important for medicines. For drugs on the market, it must be demonstrated that the levels of toxic contaminants are below the permitted limits. These impurities are used as reagents or are generated during synthesis. N-bromosuccinimide is used as a brominating agent in the synthesis of some active pharmaceutical ingredients. The determination of N-bromosuccinimide is difficult due to its high reactivity. In this work, a high-performance ion chromatographic method was developed for the determination of N-bromosuccinimide. The ion chromatographic measurement can be performed in two ways, one involves the assay of the resulting bromide ion and the other is via the assay of the 3-carbamoyl propanoic acid ion produced from the succinimide. Both acid ions were analyzed on an anion exchange column by gradient elution with potassium hydroxide eluent and detection was performed by a suppressed conductivity detector. During the method development, the results showed that the measurement of bromide ion was more selective than the measurement of 3-carbamoyl propanoic acid ion. Two different types of active pharmaceutical ingredients (API), i.e., prasugrel and favipiravir, were chosen to test the developed method and sample preparation. For both APIs, sample preparation was performed in a vial and consists of liquid–liquid extraction with an alkaline reagent. Finally, the anion exchange ion chromatography method was validated at the limit value level, and harmonized with the guidelines. For prasugrel, the quantification limits and the accuracy at the limit level are 7.2 ppm and 96.4%, while for favipiravir these are 7.5 ppm and 114.7%, respectively. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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9 pages, 937 KiB  
Communication
A Neglected Issue: Stationary Phase Retention Determination of Classic High-Speed Counter-Current Chromatography Solvent Systems
by Sha Li, Tiandan Li, Xiaochao Hu, Yong Yang, Yangyi Huang and Kai He
Separations 2022, 9(11), 357; https://doi.org/10.3390/separations9110357 - 8 Nov 2022
Viewed by 1330
Abstract
Obtaining an ideal solvent system for target compounds is still an obstacle to the wide application of high-speed counter-current chromatography (HSCCC). The partition coefficient and retention of the stationary phase are two key parameters for solvent system selection. The retention of the stationary [...] Read more.
Obtaining an ideal solvent system for target compounds is still an obstacle to the wide application of high-speed counter-current chromatography (HSCCC). The partition coefficient and retention of the stationary phase are two key parameters for solvent system selection. The retention of the stationary phase of the solvent system is roughly judged by settling time using a test tube, which is subjective and inaccurate. In this study, we demonstrated that high-resolution separation of HSCCC is tightly connected with the retention of the stationary phase. Notably, unlike the in vitro test of settling time, we investigated the retention of the stationary phase of classical biphasic solvent systems by a TBE300C HSCCC apparatus. Our results revealed that settling time is not always inversely proportional to the retention of the stationary phase. The n-hexane–ethylacetate–methanol–water solvent systems showed the highest correlation coefficient of settling time and retention of the stationary phase (r = −0.91, n = 16). N-heptane–n-butanol–acetonitrile–water solvent system showed the lowest correlation coefficient (r = −0.26, n = 7). These results may be helpful for HSCCC solvent system selection and accelerate the application of this technique. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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13 pages, 2214 KiB  
Article
Application of Humic and Fulvic Acids as an Alternative Method of Cleaning Water from Plant Protection Product Residues
by Eirini A. Makrigianni, Eirini S. Papadaki, Theodoros Chatzimitakos, Vassilis Athanasiadis, Eleni Bozinou and Stavros I. Lalas
Separations 2022, 9(10), 313; https://doi.org/10.3390/separations9100313 - 15 Oct 2022
Cited by 2 | Viewed by 2797
Abstract
Humic acids (HAs) and fulvic acids (FAs) are naturally occurring compounds that influence the fate and transportation of various compounds in the soil. Although HAs and FAs have multiple uses, the reports about their sorbent potential for environmental pollutants are scanty and sparse. [...] Read more.
Humic acids (HAs) and fulvic acids (FAs) are naturally occurring compounds that influence the fate and transportation of various compounds in the soil. Although HAs and FAs have multiple uses, the reports about their sorbent potential for environmental pollutants are scanty and sparse. In this study, HA and FA, isolated from lignite samples from two mines in Greece, were studied as sorbent materials for three active compounds of plant protection products, namely glyphosate (herbicide), cypermethrin (pyrethroid insecticide), and azoxystrobin (fungicide). According to the results, both HA and FA are promising sorbent materials for these active compounds, with HA achieving better sorption for cypermethrin and azoxystrobin, while FA was found to be more efficient for glyphosate. Moreover, their performance was not compromised by other components commonly found in commercially available herbicides/insecticides/fungicides. In addition, no significant leaching of the sorbed compounds was recorded. Finally, the two materials achieved similar sorption efficiency of the compounds from lake water. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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15 pages, 1787 KiB  
Article
Qualitative and Quantitative Detection of Acacia Honey Adulteration with Glucose Syrup Using Near-Infrared Spectroscopy
by Maja Benković, Tamara Jurina, Lucija Longin, Franjo Grbeš, Davor Valinger, Ana Jurinjak Tušek and Jasenka Gajdoš Kljusurić
Separations 2022, 9(10), 312; https://doi.org/10.3390/separations9100312 - 15 Oct 2022
Cited by 7 | Viewed by 2116
Abstract
Honey adulteration with cheap sweeteners such as corn syrup or invert syrup results in honey of lesser quality that can harm the objectives of both manufacturers and consumers. Therefore, there is a growing interest for the development of a fast and simple method [...] Read more.
Honey adulteration with cheap sweeteners such as corn syrup or invert syrup results in honey of lesser quality that can harm the objectives of both manufacturers and consumers. Therefore, there is a growing interest for the development of a fast and simple method for adulteration detection. In this work, near-infrared spectroscopy (NIR) was used for the detection of honey adulteration and changes in the physical and chemical properties of the prepared adulterations. Fifteen (15) acacia honey samples were adulterated with glucose syrup in a range from 10% to 90%. Raw and pre-processed NIR spectra of pure honey samples and prepared adulterations were subjected to Principal Component Analysis (PCA), Partial Least Squares (PLS) regression, and Artificial Neural Network (ANN) modeling. The results showed that PCA ensures distinct grouping of samples in pure honey samples, honey adulterations, and pure adulteration using NIR spectra after the Multiplicative Scatter Correction (MSC) method. Furthermore, PLS models developed for the prediction of the added adulterant amount, moisture content, and conductivity can be considered sufficient for screening based on RPD and RER values (1.7401 < RPD < 2.7601; 7.7128 < RER < 8.7157) (RPD of 2.7601; RER of 8.7157) and can be moderately used in practice. The R2validation of the developed ANN models was greater than 0.86 for all outputs examined. Based on the obtained results, it can be concluded that NIR coupled with ANN modeling can be considered an efficient tool for honey adulteration quantification. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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12 pages, 1542 KiB  
Article
Mean Centered Kinetic—Spectrophotometric Data—Continuous Wavelet Transform for Simultaneous Determination of Dopamine and Uric Acid in Presence of Ascorbic Acid at Biological Samples
by Maryam Abbasi Tarighat, Zahara Keshavarz, Gholamreza Abdi and Charalampos Proestos
Separations 2022, 9(10), 282; https://doi.org/10.3390/separations9100282 - 3 Oct 2022
Cited by 2 | Viewed by 1296
Abstract
In the present study, a rapid, practical, selective and sensitive method was proposed for simultaneous determination of dopamine (DA) and uric acid (UA). Kinetic profiles of analytes were recorded and transformed by different mother wavelets. The contribution of ascorbic acid was neglected using [...] Read more.
In the present study, a rapid, practical, selective and sensitive method was proposed for simultaneous determination of dopamine (DA) and uric acid (UA). Kinetic profiles of analytes were recorded and transformed by different mother wavelets. The contribution of ascorbic acid was neglected using mean centering of data before transformation. The concentrations range were 1.0–60.0 μmol L−1 and 7–40.0 μmol L−1, with detection limit of 0.06 and 0.30 μmol L−1 for uric acid and dopamine, respectively. The results of sym8 and db4 mother wavelets showed that proposed method creates a most selective and sensitive determination without using initial separation steps. The obtained results by CWT-sym8 and CWT-db4 were compared with partial least squares (PLS) results. The simultaneous quantitation of DA and UA with the proposed method was successfully applied in different urine and serum samples. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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19 pages, 6413 KiB  
Article
Pinus roxburghii and Nauplius graveolens Extracts Elevate Apoptotic Gene Markers in C26 Colon Carcinoma Cells Induced in a BALB/c Mouse Model
by Mosab Gad, Hassan Z. Hassouna, Khaled Mahmoud, Ahmed A. Abd-Rabou, Amal S. Abdel-Azeem, Amany M. Hegazy, Mohamed S. Abdel-Lattife, Fouad A. Ahmed, Fatih Oz, Charalampos Proestos and Ahmed A. Zaky
Separations 2022, 9(10), 277; https://doi.org/10.3390/separations9100277 - 1 Oct 2022
Cited by 2 | Viewed by 2077
Abstract
The present study aimed to evaluate the chemopreventive potential of Pinus roxburghii branch (P. roxburghii) and Nauplius graveolens (N. graveolens) extracts against human colorectal cancer (CRC) induced by C26 murine cells in a BALB/c mouse model. Real-time qRT-PCR was [...] Read more.
The present study aimed to evaluate the chemopreventive potential of Pinus roxburghii branch (P. roxburghii) and Nauplius graveolens (N. graveolens) extracts against human colorectal cancer (CRC) induced by C26 murine cells in a BALB/c mouse model. Real-time qRT-PCR was used to evaluate the apoptotic pathway by measuring the relative mRNA expression levels of the Bcl-2, Bax, Cas3, NF-κB, and PI3k genes. At the termination of the 30-day period, blood samples were collected to assay the biomarkers. The results showed a significant increase (p < 0.05) in the levels of TGF-β, CEA, CA19-9, malondialdehyde, ALT, AST, ALP, urea, and creatinine in the positive control compared to the negative control group. In addition, the glutathione reductase activity and total antioxidant activity were reduced in the positive control compared to the negative control. The biomarkers mentioned above were restored to almost normal levels after administering a safe dose (1/10) of a lethal dose of P. roxburghii and N. graveolens extracts. Administration of one-tenth of the LD50 of P. roxburghii and N. graveolens extracts caused a significant upregulation of the expression of Bax and Cas-3 and downregulation of the Bcl-2, NF-ĸB, and PI3k genes vs. the GAPDH gene as a housekeeping gene compared to the control group. Furthermore, the Bax/Bcl-2 ratio increased upon treatment. After administration of P. roxburghii and N. graveolens at a safe dose (1/10) of a lethal dose, the results showed improvement in both body weight gain and a significant decrease (p < 0.05) in tumor volume. Histopathological changes supported these improvements. Conclusively, the research outputs show that P. roxburghii and N. graveolens extracts can be utilized as potential chemopreventive agents for CRC treatment by stimulating cancer cell apoptosis and suppressing CRC survival and proliferation. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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15 pages, 4564 KiB  
Article
Filter Modified with Hydrophilic and Oleophobic Coating for Efficient and Affordable Oil/Water Separation
by Hunter Ross, Huyen Nguyen, Brian Nguyen, Ashton Foster, James Salud, Mike Patino, Yong X. Gan and Mingheng Li
Separations 2022, 9(10), 269; https://doi.org/10.3390/separations9100269 - 28 Sep 2022
Cited by 6 | Viewed by 3798
Abstract
To mitigate the damage of oil spills, a filter modified with a hydrophilic and oleophobic coating is proposed for affordable and efficient oil separation and recovery from water. The sol–gel method was chosen to produce a colloidal suspension of titanium dioxide particles for [...] Read more.
To mitigate the damage of oil spills, a filter modified with a hydrophilic and oleophobic coating is proposed for affordable and efficient oil separation and recovery from water. The sol–gel method was chosen to produce a colloidal suspension of titanium dioxide particles for its ease of production and its versatility in application for many different substrates, including paper and cloth fabric. After immersing the substrates into a titanium-containing solution, three techniques were applied to increase the production of titanium dioxide—microwave-assisted, refrigeration, and ultra-sonication. Contact angle tests were done to investigate the change in the filter’s oleophobicity. The titanium dioxide present on the surface of the filter was amorphous, but all treatment methods showed an improvement in oleophobicity. All treated filters improved oil filtration performance by up to eighty percent. The filters isolated motor oil from a mixture while allowing water to pass through. The coated filters also displayed photocatalytic activity by degrading methylene blue on its surface when exposed to sunlight, demonstrating the filter’s self-cleaning ability. For real-world applications, the filter can be supported by a stainless mesh for enhanced strength and durability. While being dragged through the water, the filter collects the surface oil, allowing water to pass through via gravity. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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13 pages, 7219 KiB  
Article
Assessing the Condition of Complex Poly-Material Artworks by Py-GC-MS: The Study of Cellulose Acetate-Based Animation Cels
by Francesca Caterina Izzo, Henk Van Keulen and Alessandra Carrieri
Separations 2022, 9(5), 131; https://doi.org/10.3390/separations9050131 - 23 May 2022
Cited by 6 | Viewed by 3309
Abstract
The material composition of a group of Rodovetri, hand-painted animation cels, made in the 1950s and 1960s for Italian television, has been determined by Flash Py-GC-MS, Thermally assisted Hydrolysis and Methylation-(Py-)GC-MS and GC-MS investigations, where, for the pyrolysis applications, the pyrolyzer is connected [...] Read more.
The material composition of a group of Rodovetri, hand-painted animation cels, made in the 1950s and 1960s for Italian television, has been determined by Flash Py-GC-MS, Thermally assisted Hydrolysis and Methylation-(Py-)GC-MS and GC-MS investigations, where, for the pyrolysis applications, the pyrolyzer is connected septum-less to the GC inlet. The condition of the selected animation cels was generally poor (yellowing, exudation, warping, cracking). The cels are made of plasticized cellulose acetate (CA) and decorated with alkyd paint. Exudating plasticizers from the CA support migrated into the paint; this has softened the paint layers and made the cels stick together. CA is known to be very unstable and easily subjected to degradation, which cannot be reversed, only slowed down by preventive conservation. Most of the cels are plasticized with bis(2-methoxyethyl) phthalate (DMEP) and triphenyl phosphate (TPP). The research shows a relationship between the degradation of CA and the presence of TPP and DMEP. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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Review

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28 pages, 2983 KiB  
Review
Mass Spectrometric Methods for Non-Targeted Screening of Metabolites: A Future Perspective for the Identification of Unknown Compounds in Plant Extracts
by Michael Sasse and Matthias Rainer
Separations 2022, 9(12), 415; https://doi.org/10.3390/separations9120415 - 7 Dec 2022
Cited by 1 | Viewed by 3601
Abstract
Phyto products are widely used in natural products, such as medicines, cosmetics or as so-called “superfoods”. However, the exact metabolite composition of these products is still unknown, due to the time-consuming process of metabolite identification. Non-target screening by LC-HRMS/MS could be a technique [...] Read more.
Phyto products are widely used in natural products, such as medicines, cosmetics or as so-called “superfoods”. However, the exact metabolite composition of these products is still unknown, due to the time-consuming process of metabolite identification. Non-target screening by LC-HRMS/MS could be a technique to overcome these problems with its capacity to identify compounds based on their retention time, accurate mass and fragmentation pattern. In particular, the use of computational tools, such as deconvolution algorithms, retention time prediction, in silico fragmentation and sophisticated search algorithms, for comparison of spectra similarity with mass spectral databases facilitate researchers to conduct a more exhaustive profiling of metabolic contents. This review aims to provide an overview of various techniques and tools for non-target screening of phyto samples using LC-HRMS/MS. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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