Journal of Separation Science

High-performance thin-layer chromatography has favorable properties for high-throughput separations with a high matrix tolerance. Sample preparation, however, is sometimes required to control specific matrix interferences and to enhance the detectability of target compounds. Trends in contemporary applications have shifted from absorbance and fluorescence detection to methods employing bioassays and mass spectrometry. Traditional methods (shake-flask, heat at reflux, Soxhlet, and hydrodistillation) are being challenged by automated instrumental approaches (ultrasound-assisted and microwave-assisted solvent extraction, pressurized liquid extraction, and supercritical fluid extraction) and the quick, easy cheap, efficient, rugged, and safe extraction method for faster and streamlined sample processing...

In this work, a novel allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase was fabricated via a surface-up thiol-ene click chemistry reaction between 7-SH-β-cyclodextrin and 1-allylimidazole-β-cyclodextrin bonded on silica surface. The structure of allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase was characterized by Fourier transform infrared spectra, 13 C NMR, thermogravimetric analysis and elemental analysis. Its chiral chromatographic performances were systematically evaluated by separating 35 racemic analytes including isoxazolines, dansyl-amino acids and flavanones under reversed-phase HPLC...

Bisphenols are used as monomers in the production of plastic materials, and they are likely to be detected in food contact materials. Due to their migration from these plastic packaging materials into food and beverages, the organoleptic properties of the products are changing and plenty of harmful effects on human health are caused, especially if consumers are exposed to higher levels of bisphenols than those established by legislation. However, because of their trace-level presence, their determination into food and beverage matrices is rather difficult...

Astragali Radix is widely used because of its dual use in medicine and food, and its quality evaluation is of great importance. In this study, a pseudo-targeted metabolomics approach based on scheduled multiple reaction monitoring was developed, and a total of 114 compounds with good linearity, sensitivity and reproducibility were selected for relative quantification, and the chemical differences between Astragali Radix of different growth patterns were further compared by chemometric analysis. With the help of multivariate and univariate analysis, 26 differential compounds between wild/semi-wild Astragali Radix and cultivated Astragali Radix were determined...

White analytical chemistry is a novel concept for the assessment of analytical methods on basis of its validation efficiency, greenness power and economical efficiency. White analytical chemistry-driven stability indicating chromatographic method has been developed for the concomitant analysis of thiocolchicoside and aceclofenac. The proposed chromatographic method has been developed using a safe and environmental-friendly organic solvent for the concomitant stability study of thiocolchicoside and aceclofenac...

Cyperus rotundus L. has been extensively used in ancient medication for the treatment of different disorders worldwide, in which sesquiterpenes are the most representative components. In this study, sesquiterpenes were effectively purified by two-dimensional counter-current chromatography in combination with continuous injection and inner-recycling mode with a solvent system of n-hexane/ethyl acetate/methanol/water (1:0.2:1:0.2, v/v). For one-dimension separation, continuous injection mode was used with three times injection and inner-recycling mode was adopted for the separation of two mixtures for two-dimensional separation...

A novel chiral group functionalized metal-organic framework, Cyclodextrin-NH-MIL-53, was synthesized and modified on the inner wall of a capillary column via a post-synthetic process. The prepared chiral metal-organic framework was utilized as a chiral capillary stationary phase and used in an open-tubular capillary electrochromatography method to enantioseparate several racemic amino acids. Excellent enantioseparation of five pairs of enantiomers was obtained in this chiral separation system (Resolutions of D/L-Alanine = 16...

Trachyspermum ammi (L.) Sprague (Apiaceae), commonly known as 'Ajwain' is distributed throughout India. Ajwain fruits contain fibre, carbohydrates, phenolic acids, flavonoids and tannins. The fruits also yield a small amount of essential oil, with Thymol as the principal constituent. Ajwain has various pharmacological activities like anti-leishmanial, antimicrobial, cytotoxic, antispasmodic, nematocidal and anthelmintic. The fruits are of high therapeutic value; thus, it becomes quite essential to evaluate the quality of Trachyspermum ammi (L...

An open tubular capillary electrochromatography column covalently bonded with polystyrene sulphonate was prepared via in situ polymerization using functionalized azo-initiator 4,4'-Azobis(4-cyanopentanoyl chloride). Scanning electron, fluorescence and atomic force microscopy techniques showed the formation of a relatively rough layer of polymer. In addition, -CN and C = O stretching vibrations from infrared spectroscopy proved the successful immobilization of the azo-initiator through covalent bonding and X-ray Photoelectron Spectroscopy confirmed the elemental composition of the formed polymer layer...

Robinia pseudoacacia flowers have attracted much attention because of numerous bioactivities. In this study, its extract showed the potential scavenging ability for 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) and 1,1-diphenyl-2-picrylhydrazyl free radicals. Under the guidance of antioxidant activity, the antioxidant extract were enriched by liquid-liquid extraction. The partition coefficients of the two main components in antioxidant extracts differed greatly, so in this study, elution-extrusion counter-current chromatography with the solvent system of n-hexane-ethyl acetate-methanol-water (2...

A method was established for the separation and determination of triadimefon and its metabolite triadimenol enantiomer residues in major complementary fruit puree for infants and young children (banana puree, pineapple puree and grape puree) by supercritical fluid chromatography. After the samples were extracted with acetonitrile and purified with solid phase extraction cartridge, Acquity Trefoil CEL2 chiral chromatographic column was adopted for separation, and gradient elution was conducted at the flow rate of 1...

A previously developed high-performance liquid chromatography method combined with pulsed amperometric detection allowed to separate many impurities of paromomycin. However, due to the presence of ion pairing agents and sodium hydroxide in the mobile phase, direct coupling to mass spectrometry for the identification of the chemical structures of the impurities was not an option. Indeed, ion suppression was encountered by trifluoroacetic acid and pentafluoroproponic acid in the mobile phase. A cation self-regenerating suppressor, which was originally designed for increasing analyte conductivity of ammonia and amines analysis in ion chromatography, was coupled between the liquid chromatography and ion trap-time of flight-mass spectrometry and almost all trifluoroacetic acid and pentafluoroproponic acid in the mobile phase was removed...

Neuraminidase is an important target in the treatment of the influenza A virus. Screening natural neuraminidase inhibitors from medicinal plants is crucial for drug research. This study proposed a rapid strategy for identifying neuraminidase inhibitors from different crude extracts (Polygonum cuspidatum, Cortex Fraxini, and Herba Siegesbeckiae) using ultrafiltration combined with mass spectrometry guided by molecular docking. Firstly, the main component library of the three herbs was established, followed by molecular docking between the components and neuraminidase...

Qishen Gubiao Granules, a traditional Chinese medicine preparation composed of 9 herbs, have been widely used to prevent and treat COVID-19 with good clinical efficacy. In the present study, an integrated strategy based on chemical profiling followed by network pharmacology and molecular docking was employed, to explore the active components and potential molecular mechanisms of Qishen Gubiao Granules in the therapy of COVID-19. Using the ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry technique, a total of 186 ingredients corresponding to 8 structure types in Qishen Gubiao preparation were identified or structurally annotated with the elucidation of the fragmentation pathways in the typical compounds...

Ziziphi spinosae semen has been widely used to treat insomnia and anxiety. To profile its chemical components, an online comprehensive two-dimensional LC-MS was developed. In this two-dimensional LC system, a novel phthalic anhydride bonded stationary phase column was combined with a C18 column. As a result, this new stationary phase exhibited remarkable differences in separation selectivity from C18, achieving a good orthogonality of 83.3%. Moreover, this new stationary phase with weaker hydrophobicity than C18 realized solvent compatibility in the online configuration...

Molecular imprinting technique has aroused great interest in preparing novel stationary phases, and the resulting materials named molecularly imprinted polymers coated silica packing materials exhibit good performance in separating diverse analytes based on their good characteristics (including high selectivity, simple synthesis, and good chemical stability). To date, mono-template is commonly used in synthesizing molecularly imprinted polymers-based stationary phases. The resulting materials always own the disadvantages of low column efficiency and restricted analytes, and the price of ginsenosides with high purity was very high...

Terpene-conjugated curcuminoids are conjugates of curcuminoids and bisabolanes in the rhizomes of Curcuma longa L. The fragmentation pathways of known three terpene-conjugated curcuminoids (bisabolocurcumin-ether, bisabocurcumin and demethoxybisabolocurcumin ether) and curcumin, demethoxycurcumin and bisdemethoxycurcumin were investigated using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in negative mode to rapidly search and discover similar unknown compounds of the acetone fraction of turmeric...

Efficient strategies for preparative separation of iridoid glycosides and flavonoid glycosides from Hedyotis diffusa using preparative HPLC combining with appropriate pretreatment technologies were developed. Four fractions (Fr.1-1, Fr.1-2, Fr.1-3 and Fr.2-1) were firstly isolated from the crude extract of Hedyotis diffusa by column chromatography with C18, resin and silica gel materials, respectively. Then, corresponding separation strategies were developed according to the polarity and chemical constituents...

N,N-dimethylacetamide is an excipient used in intravenous busulfan formulations, administered prior to haematopoietic stem cell transplantation. This study aimed to develop and validate a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of N,N-dimethylacetamide and its metabolite N-monomethylacetamide in paediatric plasma for patients receiving busulfan. A 4 μL aliquot of patient plasma was extracted using 196 μL 50% methanol solution and quantified against calibrators prepared in the extraction solvent given negligible matrix effects across three concentrations...

Fangwen Jiuwei Decoction is a traditional Chinese medicine preparation for the treatment of pneumonia developed by Shenzhen Bao'an Chinese Medicine Hospital, which shows remarkable clinical responses. Qualitative and quantitative analyses of the main active compounds are crucial for the quality control of traditional Chinese medicine prescription in clinical application. In this study, we identified nine active compounds essential for the pharmacological effects of Fangwen Jiuwei Decoction based on the analysis of the Network Pharmacology and relevant literature...