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Separations
Volume 8
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Separations, Volume 8, Issue 7 (July 2021) – 17 articles

Cover Story (view full-size image): The development of simple and sensitive methods for the determination of metals is challenging. Herein, we report the development of an on-line sorbent extraction platform coupled with FAAS for trace metal determination. The system utilized a novel sol–gel thiocyanatopropyl functionalized silica sorbent. The thiocyanate functional group has been known to form complexes with d-block metals. The main factors affecting the performance of the on-line system were investigated and optimized. Under optimum conditions, high enhancement factors, as well as good sensitivity, precision and accuracy, were observed. Finally, the proposed method was utilized for the analysis of environmental and biological samples. View This Paper
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15 pages, 2463 KiB  
Article
Experimental Study on Flocculation Effect of Tangential Velocity in a Cone-Plate Clarifier
by Yulong Zhang, Peikun Liu, Linjing Xiao, Yuekan Zhang, Xinghua Yang and Lanyue Jiang
Separations 2021, 8(7), 105; https://doi.org/10.3390/separations8070105 - 20 Jul 2021
Cited by 4 | Viewed by 2315
Abstract
A large number of particles with small size and light density in mine water are difficult to remove by traditional separation equipment. In order to improve the efficiency of mine water treatment, a cone-plate clarifier is proposed in this paper. The particle size [...] Read more.
A large number of particles with small size and light density in mine water are difficult to remove by traditional separation equipment. In order to improve the efficiency of mine water treatment, a cone-plate clarifier is proposed in this paper. The particle size distribution and their fragmentation fractal dimension were studied in 15 sampling points of the cone-plate clarifier to elucidate the process of floc growth and settling. The influence of the tangential inlet velocity size distribution characteristics was also studied. The results showed that the cone-plate clarifier can effectively improve suspended solids and turbidity removal efficiency. The floc growth and settlement courses are shown in the charts. The cone-plate clarifier was divided into four zones: micro flocculation, floc growing, settlement, and exit pipe. Because the fluid enters the cone-plate clarifier tangentially, the value of the inlet velocity and the tangential velocity are equal at the inlet feed. With the increase in tangential velocity, the flocculation efficiency first increased and then decreased. Comprehensive analysis of the particle greater than 50 μm in the effluent showed that the optimal inlet was qual to 1.63 m/s. By fitting the equations, the optimal SS and turbidity removal efficiency reached the maximum values of 92.04% and 80.18% at the inlet velocity of 1.86 m/s and 1.77 m/s, respectively. Full article
(This article belongs to the Special Issue Rapid Separations of Complex Mixtures)
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11 pages, 561 KiB  
Article
Separation of Lanthanide Isotopes from Mixed Fission Product Samples
by Leah M. Arrigo, Jun Jiang, Zachary S. Finch, James M. Bowen, Staci M. Herman, Larry R. Greenwood, Judah I. Friese and Brienne N. Seiner
Separations 2021, 8(7), 104; https://doi.org/10.3390/separations8070104 - 20 Jul 2021
Cited by 5 | Viewed by 3055
Abstract
The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies® [...] Read more.
The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies®, Inc. and a nitric acid gradient. In this work, the method was demonstrated for the separation and quantification of multiple short-lived fission product lanthanide isotopes from a fission product sample produced from the thermal irradiation of highly enriched uranium. The separations were performed in parallel in quadruplicate with reproducible results and high decontamination factors for 153Sm, 156Eu, and 161Tb. Based on the results obtained here, the fission yields for 144Ce, 153Sm, 156Eu, and 161Tb are consistent with published fission yields. This work demonstrates the effectiveness of the separations for the intended application of short-lived lanthanide fission product analysis requiring high decontamination factors. Full article
(This article belongs to the Special Issue Current Status and Prospects of Extraction and Separation Technology of Mixed Rare Earth Elements)
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18 pages, 2747 KiB  
Article
Detailed Group-Type Characterization of Plastic-Waste Pyrolysis Oils: By Comprehensive Two-Dimensional Gas Chromatography Including Linear, Branched, and Di-Olefins
by Hang Dao Thi, Marko R. Djokic and Kevin M. Van Geem
Separations 2021, 8(7), 103; https://doi.org/10.3390/separations8070103 - 16 Jul 2021
Cited by 33 | Viewed by 6161
Abstract
Plastic-waste pyrolysis oils contain large amounts of linear, branched, and di-olefinic compounds. This makes it not obvious to determine the detailed group-type composition in particular to the presence of substantial amounts of N-, S-, and O-containing heteroatomic compounds. The thorough evaluation of different [...] Read more.
Plastic-waste pyrolysis oils contain large amounts of linear, branched, and di-olefinic compounds. This makes it not obvious to determine the detailed group-type composition in particular to the presence of substantial amounts of N-, S-, and O-containing heteroatomic compounds. The thorough evaluation of different column combinations for two-dimensional gas chromatography (GC × GC), i.e., non-polar × polar and polar × non-polar, revealed that the second combination had the best performance, as indicated by the bi-dimensional resolution of the selected key compounds. By coupling the GC × GC to multiple detectors, such as the flame ionization detector (FID), a sulfur chemiluminescence detector (SCD), a nitrogen chemiluminescence detector (NCD), and a mass spectrometer (MS), the identification and quantification were possible of hydrocarbon, oxygen-, sulfur-, and nitrogen-containing compounds in both naphtha (C5–C11) and diesel fractions (C7–C23) originating from plastic-waste pyrolysis oils. Group-type quantification showed that large amounts of α-olefins (36.39 wt%, 35.08 wt%), iso-olefins (8.77 wt%, 9.06 wt%), and diolefins (4.21 wt%, 4.20 wt%) were present. Furthermore, oxygen-containing compounds (alcohols, ketones, and ethers) could be distinguished from abundant hydrocarbon matrix, by employing Stabilwax as the first column and Rxi-5ms as the second column. Ppm levels of sulfides, thiophenes, and pyridines could also be quantified by the use of selective SCD and NCD detectors. Full article
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11 pages, 5419 KiB  
Article
Effect of Geometrical Parameters on Extraction Efficiency of the Annular Centrifugal Contactor
by Yigang Su, Jianxin Tang, Xiaoxia Yang and Rijie Wang
Separations 2021, 8(7), 102; https://doi.org/10.3390/separations8070102 - 12 Jul 2021
Cited by 6 | Viewed by 2757
Abstract
The geometrical parameters of annular centrifugal contactors (ACCs) have an important influence on the extraction efficiency. The present work used a home-made 25 mm ACC constructed by 3D printing to investigate the effect of five geometrical parameters on the extraction efficiency. These parameters [...] Read more.
The geometrical parameters of annular centrifugal contactors (ACCs) have an important influence on the extraction efficiency. The present work used a home-made 25 mm ACC constructed by 3D printing to investigate the effect of five geometrical parameters on the extraction efficiency. These parameters are annular width (d), clearance height (Hc), rotor inlet diameter (Din), bottom vane number (N), and the bottom vane’s bending direction (S). Central composite design was employed to design the experiment, and the response surface methodology was used to analyze the data. The results show that Hc and Din were positive for efficiency, while d and N were negative. When the bottom vane’s bending direction was the same as the liquid helical flow direction, the efficiency improved compared to the straight vane. It is found that 3 mm d, 5 mm Hc, 6 mm Din, and four clockwise covered vanes are the parameters where the efficiency reached the highest point of 94.5%. We analyzed the interactions between the parameters based on the coefficients of the quadratic equation, and the interactions were not considered in previous studies. This work surprisingly reveals that the effects of the parameters on the extraction efficiency were not independent, and there were interactions between the parameters. The interaction between the rotor inlet diameter and annular width was significant and could not be ignored. These results could serve as a reference for optimizing extraction processes and the design of ACCs. Full article
(This article belongs to the Special Issue 3D Printing in Separation and Reaction Processes)
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11 pages, 2417 KiB  
Article
Oxidative Treatments of Pesticides in Rainwater Runoff by HOCl, O3, and O3/H2O2: Effects of pH, Humic Acids and Inorganic Matters
by Duuriimaa Ochir, Yonggu Lee, Jaegwan Shin, Sangwon Kim, Jinwoo Kwak and Kangmin Chon
Separations 2021, 8(7), 101; https://doi.org/10.3390/separations8070101 - 8 Jul 2021
Cited by 9 | Viewed by 2428
Abstract
This study systematically investigated the oxidative treatment of five selected pesticides, alachlor (ALA), carbendazim (CAR), diuron (DIU), pyrimethanil (PYR), and tebuconazole (TEB), by comparing their relative reactivities as a function of three different oxidative treatment processes (i.e., chlorine (HOCl), ozone (O3), [...] Read more.
This study systematically investigated the oxidative treatment of five selected pesticides, alachlor (ALA), carbendazim (CAR), diuron (DIU), pyrimethanil (PYR), and tebuconazole (TEB), by comparing their relative reactivities as a function of three different oxidative treatment processes (i.e., chlorine (HOCl), ozone (O3), and ozone/hydrogen peroxide (O3/H2O2)) under various oxidant dosages, reaction times, and pH conditions. For oxidative treatment, pesticide standards were spiked into rainwater. The removal efficiency of the selected pesticides varied considerably depending on the oxidative treatment processes. HOCl, O3, and O3/H2O2 treatments were highly effective at eliminating CAR (>80%) and PYR (>99%), while they were not significantly effective in removing TEB (<20%). In the case of DIU, HOCl (81%) was shown to be more effective than O3 (24%) and O3/H2O2 (49%). The removal efficiency of ALA was in the order of O3/H2O2 (49%) > O3 (20%) > HOCl (8.5%). The effect of increasing the solution pH from 5.0 to 9.0 on pesticide degradation varied between the oxidative treatment processes. Additionally, NH4+, NO2−, and humic acid in rainwater significantly inhibited pesticide degradation. Full article
(This article belongs to the Section Environmental Separations)
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13 pages, 1737 KiB  
Article
Automated Solid Phase Extraction of Cd(II), Co(II), Cu(II) and Pb(II) Coupled with Flame Atomic Absorption Spectrometry Utilizing a New Sol-Gel Functionalized Silica Sorbent
by Natalia Manousi, Abuzar Kabir, Kenneth G. Furton, George A. Zachariadis and Aristidis Anthemidis
Separations 2021, 8(7), 100; https://doi.org/10.3390/separations8070100 - 8 Jul 2021
Cited by 17 | Viewed by 3699
Abstract
In this study a simple and sensitive on-line sorbent extraction platform coupled with flame atomic absorption spectrometry for trace metals determination was developed. The system utilized for the first time a novel sol-gel thiocyanatopropyl functionalized silica as adsorbent for metal’s separation and preconcentration. [...] Read more.
In this study a simple and sensitive on-line sorbent extraction platform coupled with flame atomic absorption spectrometry for trace metals determination was developed. The system utilized for the first time a novel sol-gel thiocyanatopropyl functionalized silica as adsorbent for metal’s separation and preconcentration. The main factors affecting the performance of the on-line system were investigated and optimized. The effect of potential interfering species that occur naturally in environmental and biological samples, as well as some toxic elements, was evaluated. Under optimum conditions the enhancement factors ranged between 73 and 152 for the target analytes. The LODs of the proposed methods were 0.15 μg L−1 for Cd(II), 0.5 μg L−1 for Co(II), 0.5 μg L−1 for Cu(II) and 1.9 μg L−1 for Pb(II) for 120 s preconcentration time. The relative standard deviation values for all elements were less than 3.8%, indicating good method precision. Moreover, the sol-gel thiocyanatopropyl functionalized silica-packed microcolumns exhibited limited flow resistance and excellent packing reproducibility. Finally, the proposed method was utilized for the analysis of environmental and biological samples. Full article
(This article belongs to the Special Issue Nanomaterials in Green Analytical Chemistry)
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32 pages, 3550 KiB  
Review
Molecularly Imprinted Polymers for Dispersive (Micro)Solid Phase Extraction: A Review
by G. D. Thilini Madurangika Jayasinghe and Antonio Moreda-Piñeiro
Separations 2021, 8(7), 99; https://doi.org/10.3390/separations8070099 - 6 Jul 2021
Cited by 29 | Viewed by 5637
Abstract
The review describes the development of batch solid phase extraction procedures based on dispersive (micro)solid phase extraction with molecularly imprinted polymers (MIPs) and magnetic MIPs (MMIPs). Advantages and disadvantages of the various MIPs for dispersive solid phase extraction and dispersive (micro)solid phase extraction [...] Read more.
The review describes the development of batch solid phase extraction procedures based on dispersive (micro)solid phase extraction with molecularly imprinted polymers (MIPs) and magnetic MIPs (MMIPs). Advantages and disadvantages of the various MIPs for dispersive solid phase extraction and dispersive (micro)solid phase extraction are discussed. In addition, an effort has also been made to condense the information regarding MMIPs since there are a great variety of supports (magnetite and magnetite composites with carbon nanotubes, graphene oxide, or organic metal framework) and magnetite surface functionalization mechanisms for enhancing MIP synthesis, including reversible addition-fragmentation chain-transfer (RAFT) polymerization. Finally, drawbacks and future prospects for improving molecularly imprinted (micro)solid phase extraction (MIMSPE) are also appraised. Full article
(This article belongs to the Special Issue Molecularly Imprinted Polymers: Selective Extraction Materials for Sample Preparation)
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11 pages, 1520 KiB  
Article
Chromatographic Analysis of Aflatoxigenic Aspergillus flavus Isolated from Malaysian Sweet Corn
by Rahim Khan, Farinazleen Mohamad Ghazali, Nor Ainy Mahyudin and Nik Iskandar Putra Samsudin
Separations 2021, 8(7), 98; https://doi.org/10.3390/separations8070098 - 5 Jul 2021
Cited by 7 | Viewed by 2732
Abstract
High-performance liquid chromatography (HPLC) provides a quick and efficient tool for accurately characterizing aflatoxigenic and non-aflatoxigenic isolates of Aspergillus flavus. This method also provides a quantitative analysis of AFs in Aspergillus flavus. The method’s recovery was assessed by spiking a mixture of [...] Read more.
High-performance liquid chromatography (HPLC) provides a quick and efficient tool for accurately characterizing aflatoxigenic and non-aflatoxigenic isolates of Aspergillus flavus. This method also provides a quantitative analysis of AFs in Aspergillus flavus. The method’s recovery was assessed by spiking a mixture of AF at different concentrations to the testing medium. The validity of the method was confirmed using aflatoxigenic and non-aflatoxigenic strains of A. flavus. The HPLC system, coupled with a fluorescence detector and post-column photochemical reactor, showed high sensitivity in detecting spiked AFs or AFs produced by A. flavus isolates. Recovery from medium spiked with 10, 20, 60, and 80 ppb of AFs was found to be 73–86% using this approach. For AFB1 and AFB2, the limit of detection was 0.072 and 0.062 ppb, while the limit of quantification was 0.220 and 0.189 ppb, respectively. The AFB1 concentrations ranged from 0.09 to 50.68 ppb, while the AFB2 concentrations ranged between 0.33 and 9.23 ppb. The findings showed that six isolates produced more AFB1 and AFB2 than the acceptable limit of 5 ppb. The incidence of aflatoxigenic isolates of A. flavus in sweet corn and higher concentrations of AFB1 and AFB2 emphasize the need for field trials to explore their real potential for AF production in corn. Full article
(This article belongs to the Section Forensics/Toxins)
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15 pages, 2829 KiB  
Article
Targeted Expression of TGFBIp Peptides in Mouse and Human Tissue by MALDI-Mass Spectrometry Imaging
by Venkatraman Anandalakshmi, Guillaume Hochart, David Bonnel, Jonathan Stauber, Shigeto Shimmura, Rajamani Lakshminarayanan, Konstantin Pervushin and Jodhbir S. Mehta
Separations 2021, 8(7), 97; https://doi.org/10.3390/separations8070097 - 3 Jul 2021
Cited by 1 | Viewed by 2579
Abstract
Stromal corneal dystrophies are a group of hereditary disorders caused by mutations in the TGFBI gene. The mutant TGFBIp is prone to protein aggregation and the mutant protein gets deposited in the cornea, leading to severe visual impairment. The mutations lead to a [...] Read more.
Stromal corneal dystrophies are a group of hereditary disorders caused by mutations in the TGFBI gene. The mutant TGFBIp is prone to protein aggregation and the mutant protein gets deposited in the cornea, leading to severe visual impairment. The mutations lead to a corneal specific protein aggregation suggesting the involvement of tissue-specific factors. The exact molecular mechanism of the process of tissue-specific protein aggregation remains to be elucidated. Differential proteolysis of mutant TGFBIp is a critical component of the disease pathology. The differential proteolysis gives rise to shorter peptides that are highly aggregation-prone and initiate the aggregation cascade. Analyzing the proteolytic processing of the different TGFBIp mutant may provide insight to aid in understanding the amyloid aggregation mechanism. We developed a MALDI-MSI methodology to identify expression and spatial localization of TGFBIp peptides in the cornea. Corneal tissue samples were collected from both control and dystrophic patients (with 2 different mutations), embedded in OCT and sectioned. The sections were trypsin digested and subjected to mass spectrometry imaging using a targeted approach to detect TGFBIp. MALDI-MSI identified peptides from TGFBIp that co-localized with the amyloid corneal deposits. In addition to the relative abundance data, the specific location of the peptides across the corneal sections as molecular signatures was also identified. Spatial distribution and intensity of the TGFBIp peptides showed differences between diseased and control models but also between the two LCD phenotypes. The TGFBIp peptide with m/z of 787.474 and m/z of 1179.579 showed increased expression in both LCD mutants compared to the controls. The peptide with m/z of 929.5 showed increased expression in the LCD phenotype with H626R mutation while the peptide with m/z of 1315.802 was abundant in the sample with R124C mutation. This initial report of 2D spatial protein signature and localization of TGFBIp may be expanded to other mutations to understand the proteolytic patterns of TGFBIp in different mutations. Full article
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13 pages, 1926 KiB  
Article
Formation of Humic-Like Substances during the Technological Process of Lignohumate® Synthesis as a Function of Time
by Olga Yakimenko, Andrey Stepanov, Svetlana Patsaeva, Daria Khundzhua, Olesya Osipova and Oleg Gladkov
Separations 2021, 8(7), 96; https://doi.org/10.3390/separations8070096 - 3 Jul 2021
Cited by 11 | Viewed by 3143
Abstract
The composition, structure, and biological activity of humic-like substances (HLS) synthesized in the process of lignosulfonate conversion for the production of the humic product Lignohumate® (LH) were examined. It is shown that during the hydrolytic-oxidative process, the transformation of raw material and [...] Read more.
The composition, structure, and biological activity of humic-like substances (HLS) synthesized in the process of lignosulfonate conversion for the production of the humic product Lignohumate® (LH) were examined. It is shown that during the hydrolytic-oxidative process, the transformation of raw material and accumulation of HLS occur. Data on the chemical (elemental content, functional groups, FTIR) and spectral (absorbance and fluorescence) parameters and biological activity (in phytotest) combined with PCA show that the LH samples can be divided into three groups, depending on the duration of synthesis: initial raw material (0-time sample); “young” HLS (15–30 min), and “mature” HLS in 45–120 min of treatment. During the first 30 min, reactions similar to the ones that occur during lignin humification in nature take place: depolymerization, oxidative carboxylation, and further polycondensation with the formation and accumulation of HLS. After 45–60 min, the share of HLS reaches a maximum, and its composition stabilizes. Biological activity reaches a maximum after 45–60 min of treatment, and at that stage, the further synthesis process can be stopped. Further processing (up to 2 h and more) does not provide any added value to the humic product. Full article
(This article belongs to the Special Issue Research Progress on Extraction and Characterization of Humus)
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25 pages, 1506 KiB  
Review
Emerging Contaminants in Seafront Zones. Environmental Impact and Analytical Approaches
by José S. Câmara, Sarah Montesdeoca-Esponda, Jorge Freitas, Rayco Guedes-Alonso, Zoraida Sosa-Ferrera and Rosa Perestrelo
Separations 2021, 8(7), 95; https://doi.org/10.3390/separations8070095 - 1 Jul 2021
Cited by 9 | Viewed by 3783
Abstract
Some chemical substances have the potential to enter the coastal and marine environment and cause adverse effects on ecosystems, biodiversity and human health. For a large majority of them, their fate and effects are poorly understood as well as their use still unregulated. [...] Read more.
Some chemical substances have the potential to enter the coastal and marine environment and cause adverse effects on ecosystems, biodiversity and human health. For a large majority of them, their fate and effects are poorly understood as well as their use still unregulated. Finding effective and sustainable strategies for the identification of these emerging and/or anthropogenic contaminants that might cause polluting effects in marine environments to mitigate their adverse effects, is of utmost importance and a great challenge for managers, regulators and researchers. In this review we will evaluate the impact of emerging contaminants (ECs) on marine coastal zones namely in their ecosystems and biodiversity, highlighting the potential risks of organic pollutants, pharmaceuticals and personal care products. Emerging microextraction techniques and high-resolution analytical platforms used in isolation, identification and quantification of ECs will be also reviewed. Full article
(This article belongs to the Special Issue Analytical Methods for the Determination of Emerging Contaminants)
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18 pages, 3235 KiB  
Article
Effect of Ultrasound-Assisted Extraction Parameters on Total Polyphenols and Its Antioxidant Activity from Mango Residues (Mangifera indica L. var. Manililla)
by Anahí J. Borrás-Enríquez, Elizabeth Reyes-Ventura, Socorro J. Villanueva-Rodríguez and Lorena Moreno-Vilet
Separations 2021, 8(7), 94; https://doi.org/10.3390/separations8070094 - 30 Jun 2021
Cited by 34 | Viewed by 4614
Abstract
Manililla is a mango variety whose residues contain bioactive compounds such as polyphenols and flavonoids, with high added value. The use of environmentally friendly extraction technology would be of great relevance; hence, this study aimed to evaluate the effect of solvent relation, sonication [...] Read more.
Manililla is a mango variety whose residues contain bioactive compounds such as polyphenols and flavonoids, with high added value. The use of environmentally friendly extraction technology would be of great relevance; hence, this study aimed to evaluate the effect of solvent relation, sonication time and amplitude on the ultrasound-assisted extraction of total polyphenols in Manililla mango residues (peel, endocarp and kernel) and antioxidant activity. An experimental design 23 with a central point was used to evaluate the curvature behavior of the process variables. Conventional maceration was used as a control. The better conditions were obtained at the central point using 50% ethanol in water, 60% amplitude and 20 min of sonication time. We obtained values of up to 1814 mg GAE/100 g, 469 mg GAE/100 g and 672 mg GAE/100 g of total polyphenols and 1228 mg QE/100 g, 653 mg QE/100 g and 880 mg QE/100 g of total flavonoids for peel, endocarp and kernel, respectively. Mangiferin was quantified in ultrasound-assisted extraction at 150 mg/g in peel and 0.025 mg/g in the kernel, but it was not detectable in maceration. An antioxidant capacity of 87%, 14% and 83% inhibition for peel, endocarp and kernel, respectively, were obtained. Peel and kernel were the residues with higher potential as extraction material, while endocarp was not. Full article
(This article belongs to the Special Issue Analytical Methods and Application of Separation Techniques in Food Science)
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14 pages, 1439 KiB  
Article
Simultaneous Determination of Seven Bioactive Constituents from Salvia miltiorrhiza in Rat Plasma by HPLC-MS/MS: Application to a Comparative Pharmacokinetic Study
by Yanli Zhang, Weiliang Cui, Xianghong Liu, Ning Wang, Wenru Kong, Junyu Sui, Huifen Li and Shuqi Wang
Separations 2021, 8(7), 93; https://doi.org/10.3390/separations8070093 - 29 Jun 2021
Cited by 1 | Viewed by 2830
Abstract
The roots of Salvia miltiorrhiza (Danshen) is a precious herbal medicine used to treat cardiovascular diseases. This study establishes a high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method to quantify seven bioactive constituents from Danshen in rat plasma simultaneously. Chromatographic separation is performed on [...] Read more.
The roots of Salvia miltiorrhiza (Danshen) is a precious herbal medicine used to treat cardiovascular diseases. This study establishes a high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method to quantify seven bioactive constituents from Danshen in rat plasma simultaneously. Chromatographic separation is performed on an Agilent Eclipse Plus C18 column (150 mm × 2.1 mm, 5 μm), utilizing a gradient of acetonitrile and 0.2% formic acid aqueous solution as the mobile phase, at a flow rate of 0.6 mL/min. We conduct a tandem mass spectrometric detection with electrospray ionization (ESI) interface via multiple reaction monitoring (MRM) in both positive and negative ionization mode. Our results show that a linear relationship is established for each analyte of interest over the concentration range of 0.5–300 ng/mL with r ≥ 0.9976. The validated method is successfully used to compare the pharmacokinetic properties of crude and wine-processed Danshen extract orally administered to rats. Cmax of tanshinone IIA, Cmax, and AUC0-t of dihydrotanshinone I decrease significantly (p < 0.05) in the wine-processed group. No significant changes for other compounds are observed. These results might provide meaningful information for the further application of wine-processed Danshen and understanding of wine-processing mechanisms. Full article
(This article belongs to the Collection State of the Art in Separation Science)
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14 pages, 19629 KiB  
Article
Rhamnolipid Biosurfactants—Possible Natural Anticancer Agents and Autophagy Inhibitors
by Severina Semkova, Georgi Antov, Ivan Iliev, Iana Tsoneva, Pavel Lefterov, Nelly Christova, Lilyana Nacheva, Ivanka Stoineva, Lyudmila Kabaivanova, Galya Staneva and Biliana Nikolova
Separations 2021, 8(7), 92; https://doi.org/10.3390/separations8070092 - 28 Jun 2021
Cited by 16 | Viewed by 3502
Abstract
Background/Aim: A number of biologically active substances were proved as an alternative to conventional anticancer medicines. The aim of the study is in vitro investigation of the anticancer activity of mono- and di-Rhamnolipids (RL-1 and RL-2) against human breast cancer. Additionally, the combination [...] Read more.
Background/Aim: A number of biologically active substances were proved as an alternative to conventional anticancer medicines. The aim of the study is in vitro investigation of the anticancer activity of mono- and di-Rhamnolipids (RL-1 and RL-2) against human breast cancer. Additionally, the combination with Cisplatin was analyzed. Materials and Methods: Breast cell lines (MCF-10A, MCF-7 and MDA-MB-231) were treated with RLs and in combination with Cisplatin. The viability was analyzed using MTT assay, and investigation of autophagy was performed via acridine orange staining. Results: In contrast to the healthy cells, both tested cancer lines exhibited sensitivity to RLs treatment. This effect was accompanied by an influence on the autophagy-related acidic formation process. Only for the triple-negative breast cancer cell line (MDA-MB-231) the synergistic effect of the combined treatment (10 µM Cisplatin and 1 µg/mL RL-2) was observed. Conclusion: Based on studies on the reorganization of membrane models in the presence of RL and the data about a higher amount of lipid rafts in cancer cell membranes than in non-tumorigenic, we suggest a possible mechanism of membrane remodelling by formation of endosomes. Shortly, in order to have a synergistic effect, it is necessary to have Cisplatin andRL-2 as RL2 is a molecule inducingpositive membrane curvature. Full article
(This article belongs to the Special Issue Innovation of Analysis Methods in Pharmaceutical Chemistry)
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26 pages, 999 KiB  
Review
Analytical Methods for Extraction and Identification of Primary and Secondary Metabolites of Apple (Malus domestica) Fruits: A Review
by Maria Assunta Acquavia, Raffaella Pascale, Luca Foti, Giuseppe Carlucci, Laura Scrano, Giuseppe Martelli, Monica Brienza, Donatella Coviello, Giuliana Bianco and Filomena Lelario
Separations 2021, 8(7), 91; https://doi.org/10.3390/separations8070091 - 25 Jun 2021
Cited by 32 | Viewed by 6984
Abstract
Apples represent a greater proportion of the worldwide fruit supply, due to their availability on the market and to the high number of existing cultivar varieties and apple-based products (fresh fruit, fruit juice, cider and crushed apples). Several studies on apple fruit metabolites [...] Read more.
Apples represent a greater proportion of the worldwide fruit supply, due to their availability on the market and to the high number of existing cultivar varieties and apple-based products (fresh fruit, fruit juice, cider and crushed apples). Several studies on apple fruit metabolites are available, with most of them focusing on their healthy properties’ evaluation. In general, the metabolic profile of apple fruits strongly correlates with most of their peculiar characteristics, such as taste, flavor and color. At the same time, many bioactive molecules could be identified as markers of a specific apple variety. Therefore, a complete description of the analytical protocols commonly used for apple metabolites’ characterization and quantification could be useful for researchers involved in the identification of new phytochemical compounds from different apple varieties. This review describes the analytical methods published in the last ten years, in order to analyze the most important primary and secondary metabolites of Malus domestica fruits. In detail, this review gives an account of the spectrophotometric, chromatographic and mass spectrometric methods. A discussion on the quantitative and qualitative analytical shortcomings for the identification of sugars, fatty acids, polyphenols, organic acids, carotenoids and terpenes found in apple fruits is reported. Full article
(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)
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12 pages, 962 KiB  
Article
Characterization of Quercetin Derivatives in Crossing Combination of Habanero White and Capsicum annuum Peppers and of Anti-Inflammatory and Cytotoxic Activity
by Maria Assunta Acquavia, Raffaella Pascale, Ilaria Pappalardo, Anna Santarsiero, Giuseppe Martelli and Giuliana Bianco
Separations 2021, 8(7), 90; https://doi.org/10.3390/separations8070090 - 24 Jun 2021
Cited by 15 | Viewed by 3358
Abstract
The overproduction of reactive oxygen species and the exposure of the human body to free radicals contribute to the aetiology of many chronic health problems, such as cardiovascular disease and cancer. Supplementation with natural antioxidants could be helpful, preventing free-radical-induced tissue damage through [...] Read more.
The overproduction of reactive oxygen species and the exposure of the human body to free radicals contribute to the aetiology of many chronic health problems, such as cardiovascular disease and cancer. Supplementation with natural antioxidants could be helpful, preventing free-radical-induced tissue damage through the inhibition of the radicals’ formation. Quercetin derivatives have recently been shown to inhibit the production of inflammatory mediators and to reduce the proliferation of tumoral cells, thus being valid compounds to be promoted as dietary supplements. In this work, an HPLC-MS/MS investigation on the derivatives of quercetin in a methanolic extract of peppers deriving from an original crossing combination between Habanero white and Capsicum annuum revealed the occurrence of nine glycoconjugates, either monosaccharide, disaccharide or trisaccharide, as well as an acylated disaccharidic derivative (i.e., quercetin rhamnoside-(feruloyl-hexoside)). Due to the great variability in the quercetin derivatives’ profiles, the Habanero white hybrid pepper extract was subjected to in vitro cytotoxicity assays. The pepper extract under study was proved to have anti-inflammatory activity comparable to that shown by a Capsicum annuum pepper extract since it reduced ROS levels compared to activated cells. Due to its beneficial effects, it could be exploited as a natural constituent of nutraceutical formulations. Full article
(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)
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Article
Characterization of Moravian Wines by Selected Chemical Parameters
by Jan Javorský, Martin Král, Marek Šnirc, Július Árvay, Bohuslava Tremlová and Dani Dordević
Separations 2021, 8(7), 89; https://doi.org/10.3390/separations8070089 - 22 Jun 2021
Cited by 1 | Viewed by 2284
Abstract
Knowledge of analytical values in wines is essential to ensure product safety and compliance with legislation, and it is also essential to understand the various technologies in wine production. The aim of this work was to evaluate the analytical parameters of bottled Moravian [...] Read more.
Knowledge of analytical values in wines is essential to ensure product safety and compliance with legislation, and it is also essential to understand the various technologies in wine production. The aim of this work was to evaluate the analytical parameters of bottled Moravian wines from the Znojmo sub-region, from harvests 2015 and 2016. Basic oenological parameters and biologically active substances were evaluated. Moreover, we evaluated conditions during bottle aging in wines from harvest 2016. The results of the basic analytical values such as total phenolic acid (TPA), total sulfur dioxide (SO2), pH, actual alcohol content (EtOH), and titratable acidity (TA) were in accordance with generally known values in wines and met the legislative requirements within oenological practices. Biologically active substances, such as gallic acid, trans-caffeic acid (TCA), trans-p-coumaric acid (TPCA), rutin, ferulic acid (FA), myricetin, resveratrol, and quercetin were identified. Comparing the analytical values of individual types of wine leads to a better understanding of winemaking technology and the development of wine as such. The subject of the study was also the monitoring of produced grape pomace incurred during wine production harvest 2015 with the indication of possibilities of its further use. Full article
(This article belongs to the Special Issue Separation and Quantitative Analysis of Natural Product Extracts)
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