Separations

36 pages, 1446 KiB

Open AccessReview

Urolithins and Their Precursors Ellagic Acid and Ellagitannins: Natural Sources, Extraction and Methods for Their Determination

by Christiana Mantzourani, Eleni Kakouri, Konstantinos Palikaras, Petros A. Tarantilis and Maroula G. Kokotou

Separations 2024, 11(6), 174; https://doi.org/10.3390/separations11060174 (registering DOI) - 2 Jun 2024

Abstract

In the present review, we discuss the occurrence of ellagitannins (ETs) and ellagic acid (EA) and methods for their isolation from plant materials. We summarize analytical methods, including high-performance liquid chromatography–ultraviolet (HPLC–UV) and liquid chromatography–mass spectrometry (LC–MS), for the determination of ETs, EA [...] Read more.

In the present review, we discuss the occurrence of ellagitannins (ETs) and ellagic acid (EA) and methods for their isolation from plant materials. We summarize analytical methods, including high-performance liquid chromatography–ultraviolet (HPLC–UV) and liquid chromatography–mass spectrometry (LC–MS), for the determination of ETs, EA and their bioactive metabolites urolithins (Uros) in samples of plant and food origin, as well as in biological samples, such as plasma, urine and feces. In addition, the current interest in the bioactivities of Uros is discussed in brief. Full article

(This article belongs to the Special Issue Applications of Separation and Purification Techniques for Natural Products Derived from Plants Source)

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19 pages, 2579 KiB

Open AccessArticle

In Situ Formed Organic Ion-Associate Liquid-Phase Microextraction without Centrifugation from Aqueous Solutions Using Thymol Blue and Estrogens

by Sachiko Osada, Seira Takahashi, Kazuto Sazawa, Hideki Kuramitz, Nozomi Kohama, Takuya Okazaki, Shigeru Taguchi and Noriko Hata

Separations 2024, 11(6), 173; https://doi.org/10.3390/separations11060173 (registering DOI) - 2 Jun 2024

Abstract

In this study, we present a method for ion-associated liquid phase (IALP) separation and concentration of analytes from an aqueous matrix into an IALP formed in situ by the charge neutralization reaction of organic cations and anions, without centrifugation. The effects of various [...] Read more.

In this study, we present a method for ion-associated liquid phase (IALP) separation and concentration of analytes from an aqueous matrix into an IALP formed in situ by the charge neutralization reaction of organic cations and anions, without centrifugation. The effects of various factors on the extraction efficiency and other parameters are investigated, whereas no instrumental stirring, such as vortexing or ultrasonics, is required because the solvent (IALP) is formed in situ. The organic cation and anion used are ethylhexyloxypropylammonium and dodecyl sulfate, respectively. The developed in situ IALP microextraction method for phase separation without centrifugation is tested using the thymol blue dye and several endocrine disruptors. The tested endocrine disruptors (bisphenol A, 17β-estradiol, 17α-ethinylestradiol, and estrone) are analyzed via high-performance liquid chromatography/fluorescence detection, with respective detection limits of 0.02, 0.02, 0.02, and 0.4 μg L⁻¹, and the corresponding enrichment factor ranging from 47 to 71. This IALP microextraction method can be used to separate and concentrate environmental water samples of different matrices. The employed IALP is fast and easy to use, enables an approximately 100-fold analyte concentration, and has a high affinity for estrogens, thus holding promise for the separation, concentration, and quantitation of diverse trace analytes. Full article

(This article belongs to the Section Purification Technology)

15 pages, 810 KiB

Open AccessArticle

The Essential Oil Composition of Eryngium galioides Lam.—An Endemic Species of the Iberian Peninsula

by Jesús Palá-Paúl, Rubén Abad-Calderón, María José Pérez-Alonso, Joseph J. Brophy and Ana C. Soria

Separations 2024, 11(6), 172; https://doi.org/10.3390/separations11060172 (registering DOI) - 1 Jun 2024

Abstract

The Eryngium L. genus belongs to the Apiaceae family and, with about 250 species, has a cosmopolitan distribution. Only fourteen of the twenty-six species described in Flora Europaea grow in the Iberian Peninsula. One of these is Eryngium galioides Lam., a small annual [...] Read more.

The Eryngium L. genus belongs to the Apiaceae family and, with about 250 species, has a cosmopolitan distribution. Only fourteen of the twenty-six species described in Flora Europaea grow in the Iberian Peninsula. One of these is Eryngium galioides Lam., a small annual plant (2–30 cm) that grows in open dry places in the mid-west of the Iberian Peninsula. For this study, the whole plant (aerial parts and roots) of this species was gathered in Guadalajara (Spain). The essential oil of this population was extracted by hydro-distillation and analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS). It is worth noting that this species gave rise to a relatively high essential oil yield (0.48%) in comparison with other species of this genus. E. galioides oil consisted of a complex mixture of more than 70 compounds. The main constituents of this oil were identified as valencene (49.7%) and a phyllocladene isomer (23.7%), both representing more than the 70% of the total oil. Other representative compounds of this oil were found to be β-chamigrene (6.0%), γ-muurolene (3.4%), (E)-caryophyllene (3.0%) and β-elemene (1.6%). As far as we know, this is the first report about the chemical composition of E. galioides essential oils. With this work, we contribute to the knowledge of this genus and provide a chemical and botanical basis to promote the in vitro cultivation of E. galioides as a source of essential oils rich in bio-actives for application in different fields. Full article

(This article belongs to the Special Issue Analysis, Isolation and Biological Activities of Polyphenols from Terrestrial and Marine Sources)

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23 pages, 2206 KiB

Open AccessReview

Extraction and Purification of Catechins from Tea Leaves: An Overview of Methods, Advantages, and Disadvantages

by Oana Cioanca, Ionut-Iulian Lungu, Ioana Mita-Baciu, Silvia Robu, Ana Flavia Burlec, Monica Hancianu and Florina Crivoi

Separations 2024, 11(6), 171; https://doi.org/10.3390/separations11060171 (registering DOI) - 1 Jun 2024

Abstract

This review study explores the complex methods involved in the extraction and purification of polyphenols, specifically catechins, prominent compounds that are bioactive and found in plant-based extracts and foods like tea. This study also addresses the challenges that may arise from the complex [...] Read more.

This review study explores the complex methods involved in the extraction and purification of polyphenols, specifically catechins, prominent compounds that are bioactive and found in plant-based extracts and foods like tea. This study also addresses the challenges that may arise from the complex chemical structure of catechins and their inherent variability across botanical sources. Despite these shortcomings and obstacles, catechins and catechin derivatives present significant potential, particularly in healthcare but also in the food industry. Their enhanced antioxidant properties have been exhaustively investigated and associated with countless health benefits, making them promising agents with numerous applications, most notably in healthcare against chronic diseases. Furthermore, catechins have numerous applications across various industries, including food and beverage, cosmetics, agriculture, and materials science. This review is a compilation of the most notable and recent research found in the literature and emphasizes the importance of continued research and innovation in catechin separation, extraction, and utilization, which hold promise for advancing human health and technological progress across multiple domains. Full article

(This article belongs to the Special Issue Advanced Research on Extraction and Analysis of Plant Extracts)

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22 pages, 3840 KiB

Open AccessArticle

Remediation of Methyl Orange Dye in Aqueous Solutions by Green Microalgae (Bracteacoccus sp.): Optimization, Isotherm, Kinetic, and Thermodynamic Studies

by Ahmad Al Shra’ah, Abdullah T. Al-Fawwaz, Mohammed M. Ibrahim and Eid Alsbou

Separations 2024, 11(6), 170; https://doi.org/10.3390/separations11060170 - 30 May 2024

Viewed by 67

Abstract

This study aims to assess the ability of old, immobilized fresh, and free fresh green microalgae (a Bracteacoccus sp.) to remove methyl orange (MO) dye from aqueous solutions. The effects of four factors, including initial MO concentration (5–25 mg L⁻¹), adsorbent [...] Read more.

This study aims to assess the ability of old, immobilized fresh, and free fresh green microalgae (a Bracteacoccus sp.) to remove methyl orange (MO) dye from aqueous solutions. The effects of four factors, including initial MO concentration (5–25 mg L⁻¹), adsorbent dose (0.02–0.10 g mL⁻¹), temperature (4–36 °C), and contact time (5–95 min), were examined. The Box–Behnken design (BBD) was used to determine the number of required experiments and the optimal conditions expected to provide the highest removal percentage of MO dye from aqueous solutions. The experimental data were applied to four isotherm models (Langmuir, Freundlich, Dubinin–Radushkevich (D–R), and Temkin isotherm models) and three kinetic models (pseudo–first–order, pseudo–second–order, and Elovich kinetic models). The results indicate that the highest removal of MO (97%) could be obtained in optimal conditions consisting of an initial MO concentration of 10.0 mg L⁻¹, an adsorbent dose of 0.10 g mL⁻¹, a temperature of 20 °C, and a contact time of 75 min. Moreover, the experimental data were best fitted by the Langmuir and Temkin isotherm models and followed a pseudo-second-order kinetic model. The interaction between MO and the Bracteacoccus sp. was confirmed by UV and ESI/MS analyses, indicating that MO removal occurred via both sorption and degradation processes. Full article

(This article belongs to the Special Issue Adsorption and Remediation of Emerging Pollutants from Water and Soil)

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14 pages, 2068 KiB

Open AccessArticle

The Prevalence of Benzodiazepine Use among Italian Drivers in 15,988 Cases of Driving License Regranting from 2015 to 2023: Risks and Implications for Driving Fitness

by Lucrezia Stefani, Federico Mineo, Leonardo Romani, Francesca Vernich, Carmelo Russo, Luigi Tonino Marsella and Roberta Tittarelli

Separations 2024, 11(6), 169; https://doi.org/10.3390/separations11060169 - 29 May 2024

Viewed by 236

Abstract

The use of benzodiazepines is strongly associated with an increased risk of traffic accidents due to their side effects of sedation and drowsiness, which can significantly impair driving performance. The main aim of our study was to investigate the trend of benzodiazepine use [...] Read more.

The use of benzodiazepines is strongly associated with an increased risk of traffic accidents due to their side effects of sedation and drowsiness, which can significantly impair driving performance. The main aim of our study was to investigate the trend of benzodiazepine use over nine years (2015–2023) in a population of 15,988 subjects who had their license suspended for driving under the influence (DUI) of alcohol or drugs. Among the 15,988 users accessed to our laboratory, 924 tested positive for at least one benzodiazepine. An increase in the number of positive-testing users was observed in the period 2015–2018, followed by a slight decrease in 2019. Overall, the trend of benzodiazepine use was stable over the next four years (2020–2023), with the highest incidence in 2022. The most common benzodiazepines, and/or metabolites, found in urine samples were α-OH-alprazolam (28.66%; n = 366) and oxazepam (27.25%; n = 348). Several cases of mixed positivity were observed in the study population. The main substances taken with benzodiazepines were cocaine and Δ9-tetrahydrocannabinol. Our findings suggest that people taking benzodiazepines should be monitored, as these have a relevant impact on driving ability in addition to significant interindividual differences in the behavioral effects of benzodiazepines on driving performance. Full article

(This article belongs to the Special Issue Forensic Toxicology: Biological Sampling and Development of Analytical Techniques)

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11 pages, 1080 KiB

Open AccessArticle

Simultaneous Quantification of Twelve Compounds from Bamboo/Wood Vinegar by Gas Chromatography-Mass Spectrometry

by Jianjun Wang, Bao Zhang, Hang Xun, Xi Yao and Feng Tang

Separations 2024, 11(6), 168; https://doi.org/10.3390/separations11060168 - 28 May 2024

Viewed by 238

Abstract

Bamboo vinegar is a liquid biomass with a huge yield and complex chemical composition. At present, the relative quantification of bamboo vinegar has been investigated in most studies. To analyze twelve compounds from bamboo vinegar simultaneously, gas chromatography-mass spectrometry and an external standard [...] Read more.

Bamboo vinegar is a liquid biomass with a huge yield and complex chemical composition. At present, the relative quantification of bamboo vinegar has been investigated in most studies. To analyze twelve compounds from bamboo vinegar simultaneously, gas chromatography-mass spectrometry and an external standard method were used to develop an analytical method. In this method, chromatographic separations of all compounds were above 1.5. The linear range was between 0.100 and 10.000 mg/L, and the coefficient of determination (R²) was between 0.9981 and 0.9997, indicating a good linear relationship. The limit of detection (LOD) was between 0.004 and 0.780 mg/L; the limit of quantitation (LOQ) was between 0.016 and 3.120 mg/L; the relative standard deviations (RSDs) of instrument precision and method stability were less than 8%; the recovery rate was between 89.25% and 113.77%, and its RSD was between 0.44% and 5.70%. Using this method, fourteen bamboo vinegars and six wood vinegars were analyzed, and it was found that the content of propionic acid, phenol, and 2-methoxyphenol was higher in most samples. In addition, the differences in physicochemical properties between distilled bamboo vinegar and its original solution after atmospheric distillation were investigated. Full article

(This article belongs to the Special Issue Comprehensive Separations of Complex Mixtures by Gas Chromatography/Mass Spectrometry (Volume II))

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19 pages, 4562 KiB

Open AccessArticle

Early Identification of Olive Oil Defects throughout Shelf Life

by Flávia Freitas, Maria João Cabrita and Marco Gomes da Silva

Separations 2024, 11(6), 167; https://doi.org/10.3390/separations11060167 - 27 May 2024

Viewed by 252

Abstract

The unique aroma and flavor of extra virgin olive oil (EVOO) are generally associated with its volatile composition, which includes a variety of components responsible for positive attributes as well as sensory defects which result from chemical oxidation processes and the action of [...] Read more.

The unique aroma and flavor of extra virgin olive oil (EVOO) are generally associated with its volatile composition, which includes a variety of components responsible for positive attributes as well as sensory defects which result from chemical oxidation processes and the action of exogenous enzymes. In this study, a robust analytical method, headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME-GC/MS), was developed to tentatively identify volatile organic compounds (VOCs) as markers of positive and negative attributes, correlating them with relative percentages to estimate the risk of disqualification during the shelf life of EVOO. Significant differences (p < 0.05) were identified in the levels of VOCs over time, mainly those derived from the lipoxygenase (LOX) pathway. Principal component analysis (PCA) was applied to process the experimental data. The ratio of E-2-hexenal to acetic acid allowed for the prediction of the disqualification of monovarietal EVOO by the sensory panel. Full article

(This article belongs to the Section Analysis of Food and Beverages)

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30 pages, 3729 KiB

Open AccessReview

Current Trends and Technological Advancements in the Study of Honey Bee-Derived Peptides with an Emphasis on State-of-the-Art Approaches: A Review

by Wissam K. Al-Rubaie, Dhia F. Al-Fekaiki, Alaa Kareem Niamah, Deepak Kumar Verma, Smita Singh and Ami R. Patel

Separations 2024, 11(6), 166; https://doi.org/10.3390/separations11060166 - 27 May 2024

Viewed by 517

Abstract

Honey is a natural product that is used by a large number of people because of its distinctive compositional constituents, which have a considerable impact on its market value. The distinctive combination of amino acids and sugars found in honey’s composition, along with [...] Read more.

Honey is a natural product that is used by a large number of people because of its distinctive compositional constituents, which have a considerable impact on its market value. The distinctive combination of amino acids and sugars found in honey’s composition, along with its peptide content, could potentially provide several benefits to human health. During the past few years, cutting-edge techniques have been developed and used for the purpose of investigating, identifying, and characterizing peptides that are produced from honey bees. Therefore, the purpose of this review is to examine current trends and technological advancements in the study of honey bee-derived peptides, focusing on innovative and cutting-edge methods. Furthermore, this review explores various attributes of honey and its components, including the honey bee-derived peptide defensin-1. In addition, this review investigates various methods for separating and purifying peptides, as well as the factors that affect these methods. Additionally, defensin-1, a peptide produced by honey bees, is discussed along with its antioxidant and antimicrobial capabilities. In addition, this review focuses on cutting-edge and innovative omic methods used to study honey bee peptides, as well as the significance of artificial intelligence tools in their investigation. Consequently, the review paper delves into various significant obstacles faced by researchers and scientists studying honey bee peptides, while also offering an extensive range of fascinating opportunities and possibilities for future research for those interested in groundbreaking discoveries in this area. Full article

(This article belongs to the Section Analysis of Food and Beverages)

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22 pages, 13618 KiB

Open AccessArticle

Accessing the Medicinal Potential of Mallotus philippensis: Comprehensive Exploration of Antioxidant and Antibacterial Properties through Phytochemical Analysis and Extraction Techniques

by Ahmad Ali, Hangping Chen, He Xu, Shuo Wang and Shun Yao

Separations 2024, 11(6), 165; https://doi.org/10.3390/separations11060165 - 27 May 2024

Viewed by 393

Abstract

Plants serve as reservoirs of bioactive compounds endowed by nature, rendering them promising subjects for investigating chemical diversity. Despite their potential, much remains untapped, whether in standardized extracts or isolated pure compounds. This unexplored terrain has paved the way for significant discoveries in [...] Read more.

Plants serve as reservoirs of bioactive compounds endowed by nature, rendering them promising subjects for investigating chemical diversity. Despite their potential, much remains untapped, whether in standardized extracts or isolated pure compounds. This unexplored terrain has paved the way for significant discoveries in pharmaceuticals. Notably, research has delved into the medicinal properties of Mallotus philippensis, a prominent plant in South Asia. Employing meticulous extraction techniques such as maceration, the fruit of this plant underwent initial antimicrobial screening, revealing encouraging results. Subsequent fractionation of the plant’s extracts via liquid–liquid extractions, utilizing dichloromethane and absolute ethanol, facilitated further analysis. Evaluating these fractions for antibacterial activity demonstrated efficacy against various pathogenic microorganisms, particularly Pseudomonas aeruginosa and Escherichia coli, notably by the ethanolic and dichloromethane extracts. Furthermore, a comprehensive phytochemical analysis unveiled the presence of alkaloids, flavonoids, saponins, glycosides, phenols, and tannins. An assessment of the extracts’ antioxidant potential via the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay showcased significant activity, with a radical scavenging rate of 97%. This underscores the significance of utilizing fruit remnants, which are often rich in valuable chemical constituents yet commonly discarded, thereby adding value to both the species and the environment. Further investigation focused on the composition of Mallotus philippensis fruit, encompassing volatile and non-volatile metabolites through HPLC-MS analysis. Additionally, this study introduced the application of ionic liquid-loaded polysulfone microcapsules to enrich target constituents from crude extracts. An exploration of the key separation conditions, results, and recycling performance of these microcapsules provided insights for future research endeavors. Overall, this comprehensive study of Mallotus philippensis fruit extracts establishes a foundation for the ongoing exploration and development of this medicinal plant. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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18 pages, 9752 KiB

Open AccessArticle

Carwash Oily Wastewater Separated by Ultrafiltration

by Piotr Woźniak and Marek Gryta

Separations 2024, 11(6), 164; https://doi.org/10.3390/separations11060164 - 25 May 2024

Viewed by 229

Abstract

In the present study, oily wastewater generated during car washing was separated using ultrafiltration (UF). Wastewater was collected from the settling tank of two manual car washes. In addition to pollutants removed from cars, such wastewater contains surfactants, the impact of which on [...] Read more.

In the present study, oily wastewater generated during car washing was separated using ultrafiltration (UF). Wastewater was collected from the settling tank of two manual car washes. In addition to pollutants removed from cars, such wastewater contains surfactants, the impact of which on the process of ultrafiltration has been analyzed. For this purpose, the application of commercial UF polyethersulfone (PES) membranes (10 and 100 kDa) and polyvinylidene fluoride (PVDF) tubular membranes (100 kDa) was comprehensively examined. Almost 100% removal of oil contaminants was achieved; however, intensive fouling was noticed. The membrane morphology and deposit composition were studied using a scanning electron microscope coupled with energy dispersion spectrometry. The fouling phenomenon was reduced by washing the membranes with an alkaline cleaning agent (pH = 11.5), which is used in car washes to remove insects. The filtration/membrane washing cycle was repeated many times to achieve stable operation of the membrane modules. The UF process was carried out for 120–140 h, and the separation efficiency was analyzed based on the rejection of dextrans, COD, BOD, total N and P, turbidity, and anionic surfactants. It has been found that cyclic repeated washing did not deteriorate the membrane’s performance, and a permeate with a turbidity of 0.12–0.35 NTU was obtained. Thus, cleaning agents used for washing cars can also be used for membrane cleaning. Full article

(This article belongs to the Special Issue Advanced Oil–Water Separation Technology)

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15 pages, 1857 KiB

Open AccessArticle

Accumulation of Particles in an Annular Centrifugal Contactor Cascade and the Effect upon the Extraction of Nitric Acid

by Alastair Baker, Alex Fells, Natalia Domenech-Garcia, Chris J. Maher and Bruce C. Hanson

Separations 2024, 11(6), 163; https://doi.org/10.3390/separations11060163 - 23 May 2024

Viewed by 363

Abstract

Centrifugal contactors (CCs) are a technology candidate for the development of advanced reprocessing flowsheets. While they offer many advantages, such as process intensification, there are still uncertainties regarding their industrial deployment. The presence of particles in the process streams in particular may present [...] Read more.

Centrifugal contactors (CCs) are a technology candidate for the development of advanced reprocessing flowsheets. While they offer many advantages, such as process intensification, there are still uncertainties regarding their industrial deployment. The presence of particles in the process streams in particular may present a challenge to both performance and operability. Preliminary studies have been undertaken to evaluate the accumulation of particles in the contactors and the effect upon the extraction behaviour of nitric acid. Aluminium oxide (Al₂O₃) particles were suspended in the aqueous feed solution during the operation of a three-stage, 40 mm diameter CC cascade. The presence of insoluble solid particles in the aqueous feed, up to 7 g/L, were not observed to affect phase separation and entrainment under the experimental conditions investigated. The particles were centrifuged out of solution and accumulated as a thin cake/bed in the rotors of each stage. This work also illustrates that particles do entrain through the cascade. The predominant effect on the rate of accumulation was particle concentration in the aqueous feed solution, and increasing solids loading was observed to have an impact upon the extraction of nitric acid across the cascade. Full article

(This article belongs to the Section Separation Engineering)

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14 pages, 3318 KiB

Open AccessArticle

Hyphenation of Thermodesorption into GC × GC-TOFMS for Odorous Molecule Detection in Car Materials: Column Sets and Adaptation of Second Column Dimensions to TD Pressure Constraints

by Romain Klein, José Dugay, Jérôme Vial, Didier Thiébaut, Guy Colombet, Donatien Barreteau and Guillaume Gruntz

Separations 2024, 11(6), 162; https://doi.org/10.3390/separations11060162 - 23 May 2024

Viewed by 306

Abstract

Vehicle interior air quality is an issue of growing interest among car manufacturers and customers. GC-MS is the benchmark method for the analysis of indoor air or material emissions. It is suitable for the quantification of target pollutants and the most abundant compounds. [...] Read more.

Vehicle interior air quality is an issue of growing interest among car manufacturers and customers. GC-MS is the benchmark method for the analysis of indoor air or material emissions. It is suitable for the quantification of target pollutants and the most abundant compounds. It fails, however, to uncover the true molecular complexity of these samples. In the present study, we describe the development of a TD-GC × GC-TOFMS method designed to detect polar and potentially odorous molecules in car material emissions. Attention is paid to the hyphenation of the thermodesorber and the gas chromatograph, both at software and hardware levels, and the constraints due to pressure limitations on the thermodesorber (evaluated at 414 kPa/60 psi at the end of the temperature ramp and at 138 kPa/20 psi at rest). A compromise was made for the 2D column length and diameter to balance separation and pressure (50 × 0.18 × 0.18 cm × mm × µm + 60 cm transfer line selected). On various materials, we were able to observe several hundreds of polar molecules, among them were between 75 and 150 odorants per material. This work lays the foundation for the widespread screening of potential odorants in car material emissions. Full article

(This article belongs to the Collection Feature Paper Collection in Section Chromatographic Separations)

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9 pages, 962 KiB

Open AccessArticle

Two-Dimensional Thin-Layer Chromatography as an Accessible, Low-Cost Tool for Lipid-Class Profile Screening

by Zipora Tietel

Separations 2024, 11(6), 161; https://doi.org/10.3390/separations11060161 - 23 May 2024

Viewed by 316

Abstract

The interest in lipid composition profiling is significantly increasing as research reveals the immense importance of lipids in medicine, plant science, food and agriculture. However, lipidomic analysis requires high-end specialty equipment. We used two-dimensional thin-layer chromatography (2D-TLC) as a readily available, low-cost tool [...] Read more.

The interest in lipid composition profiling is significantly increasing as research reveals the immense importance of lipids in medicine, plant science, food and agriculture. However, lipidomic analysis requires high-end specialty equipment. We used two-dimensional thin-layer chromatography (2D-TLC) as a readily available, low-cost tool for basic lipidomic profiling of lipid classes in algal samples in the models Chlamydomonas reinhardtii, Auxenochlorella protothecoides, and Euglena gracilis, validating lipid class identification using an LC-MS/MS analysis. Algal lipid extracts were separated on a 2D-TLC plate, and TLC analysis was followed by scraping individual TLC spots off the plate, and a subsequent liquid chromatography separation and tandem mass spectrometry (LC-MS/MS) analysis. For comparison, crude lipid extracts were also injected directly to the LC-MS/MS system. Lipid class annotation was achieved by a combination of accurate mass, retention time information, neutral loss and fragment ion analysis by MS2Analyzer, and by matching spectra to LipidBlast MS/MS library. Overall, we were able to identify 15 lipid classes, and to adequately profile the lipid classes in all three organisms. This TLC method is thus suggested as an accessible tool for lipid class profiling of algal, plant, and food lipids, alike, when a rapid and simple analysis is required, e.g., for screening purposes. Full article

(This article belongs to the Special Issue Chromatography for the Separation and Detection of Metabolites)

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20 pages, 3162 KiB

Open AccessArticle

Evaluation of CO₂/H₂O Co-Adsorption Models for the Anion Exchange Resin Lewatit VPOC 1065 under Direct Air Capture Conditions Using a Novel Lab Setup

by Florian M. Chimani, Aditya Anil Bhandari, Andreas Wallmüller, Gerhard Schöny, Stefan Müller and Josef Fuchs

Separations 2024, 11(6), 160; https://doi.org/10.3390/separations11060160 - 22 May 2024

Viewed by 354

Abstract

This study aimed to develop a laboratory-scale direct air capture unit for evaluating and comparing amine-based adsorbents under temperature vacuum swing adsorption conditions. The experimental campaign conducted with the direct air capture unit allowed for the determination of equilibrium loading, CO₂ uptake [...] Read more.

This study aimed to develop a laboratory-scale direct air capture unit for evaluating and comparing amine-based adsorbents under temperature vacuum swing adsorption conditions. The experimental campaign conducted with the direct air capture unit allowed for the determination of equilibrium loading, CO₂ uptake capacity, and other main performance parameters of the investigated adsorbent Lewatit VP OC 1065^®. The investigations also helped to understand the co-adsorption of CO₂ and H₂O on the tested material, which is crucial for improving temperature vacuum swing adsorption processes. This was achieved by obtaining pure component isotherms for CO₂ and H₂O and using three different co-adsorption isotherm models from the literature. It was found that the weighted average dual-site Toth model emerged as the most accurate and reliable model for simulating this co-adsorption behaviour. Its predictions closely align with the experimental data, particularly in capturing the adsorption equilibrium at various temperatures. It was also observed that this lab-scale unit offers advantages over thermogravimetric analysis when conducting adsorption experiments on the chosen amine. The final aim of this study is to provide a pathway to develop devices for testing and developing efficient and cost-effective adsorbents for direct air capture. Full article

(This article belongs to the Topic Carbon Capture Science & Technology (CCST))

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13 pages, 2450 KiB

Open AccessArticle

Effect of a Chitosan-Based Packaging Material on the Domestic Storage of “Ready-to-Cook” Meat Products: Evaluation of Biogenic Amines Production, Phthalates Migration, and In Vitro Antimicrobic Activity’s Impact on Aspergillus Niger

by Antonella Maria Aresta, Nicoletta De Vietro, Giovanna Mancini and Carlo Zambonin

Separations 2024, 11(6), 159; https://doi.org/10.3390/separations11060159 - 21 May 2024

Viewed by 349

Abstract

The consumption of “ready-to-cook” foods has been experiencing rapid expansion due to modern lifestyles, and they are often sold in economical multipacks. These foods necessitate packaging that maintains their quality for extended periods of time during home storage once the original packaging is [...] Read more.

The consumption of “ready-to-cook” foods has been experiencing rapid expansion due to modern lifestyles, and they are often sold in economical multipacks. These foods necessitate packaging that maintains their quality for extended periods of time during home storage once the original packaging is opened. This study evaluates a chitosan-based film derived from low- and high-molecular-weight (MW) chitosan in acetic acid without synthetic additives as an alternative packaging material for “ready-to-cook” beef burgers. The burgers were stored at 8 °C after being removed from their sales packaging. A commercial polyethylene (PE) film designed for food use, devoid of polyvinylchloride (PVC) and additives, served as the reference material. The production of six biogenic amines (BAs), indicative of putrefactive processes, was monitored. Additionally, the release of four phthalates (PAEs), unintentionally present in the packaging films, was assessed using solid-phase microextraction coupled with gas chromatography/mass spectrometry (SPME-GC/MS). Microbiological tests were conducted to investigate the antimicrobial efficacy of the packaging against Aspergillus Niger NRR3112. The results showed that the chitosan-based films, particularly those with low MW (LMW), exhibited superior meat preservation compared to the PE films. Furthermore, they released PAEs below legal limits and demonstrated the complete inhibition of fungal growth. These findings highlight the potential of chitosan-based packaging as a viable and effective option for extending the shelf-life and maintaining the quality of “ready-to-cook” meat products during domestic storage. Full article

(This article belongs to the Section Analysis of Food and Beverages)

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