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Journal of Separation Science

Hailin Cong, Bing Yu, Chao Tian, Shuai Zhang, Hua Yuan
Monodisperse silica particles with average diameters of 1.9-2.9 μm were synthesized by a modified Stöber method, in which tetraethyl orthosilicate was continuously supplied to the reaction mixture containing KCl electrolyte, water, ethanol and ammonia. The obtained silica particles were modified by self-assembly with positively charged photosensitive diazoresin on the surface. After treatment with ultraviolet light, the ionic bonding between silica and diazoresin was converted into covalent bonding through a unique photochemistry reaction of diazoresin...
September 13, 2017: Journal of Separation Science
Xiaojing Liang, Licheng Wang, Shuai Wang, Yijing Li, Yong Guo
Packed cartridges have been widely used in solid-phase extraction. However, there are still some drawbacks, such as they are blocked easily and the method is time-consuming. In view of the advantages of monoliths, a monolithic extraction material has been directly synthesized in a glass syringe without any gap between the monolith and syringe's inner wall. The monolithic syringe was modified with graphene oxide by loading a graphene oxide dispersion onto it. The content of graphene oxide and the surface topography of the monolith have been evaluated by elemental analysis and scanning electron microscopy, respectively, which confirmed the successful modification...
September 12, 2017: Journal of Separation Science
Yang Chen, Li-Zi Yin, Ling Zhao, Gang Shu, Zhi-Xiang Yuan, Hua-Lin Fu, Cheng Lv, Ju-Chun Lin
The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box-Behnken design was used to analyze the effects of ethanol concentration, liquid-solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high-performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1-,diphenyl-2-picrylhydrazyl, hydroxyl radical scavenging test and reduction force)...
September 12, 2017: Journal of Separation Science
Xiaoling Yu, Shouer Lin, Jinque Zhang, Liying Huang, Hong Yao, Shaoguang Li
To establish a systematic method for the extraction, purification, characterization and antitumor activity study of polysaccharide from artificially cultivated Anoectochilus roxburghii(wall.) Lindl. (AC-ARPS). High-speed counter current chromatography with two-phase aqueous systems was successfully applied to purify AC-ARPS after one-step separation. The purity of the AC-ARPS obtained by phenol/sulfuric acid method was 95.01%. The chemical structures of AC-ARPS were identified by a series analytical methods including high-performance liquid chromatography and liquid chromatography with mass spectrometry...
September 11, 2017: Journal of Separation Science
Ding-Tao Wu, Yong Deng, Jing Zhao, Shao-Ping Li
To accurately characterize branched polysaccharides with high molecular weights from medicinal and edible mushrooms and identify the limitations of size exclusion chromatography, molecular characteristics of polysaccharides from Tremella fuciformis were determined and compared by asymmetrical flow field-flow fractionation coupled with multi-angle laser light scattering and refractive index detection, and size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detection, respectively...
September 11, 2017: Journal of Separation Science
Tobias M Richter, Graham T Eyres, Patrick Silcock, Phil J Bremer
The volatile organic compound profile in beer is derived from hops, malt, yeast, and interactions between the ingredients, making it very diverse and complex. Due to the range and diversity of the volatile organic compounds present, the choice of the extraction method is extremely important for optimal sensitivity and selectivity. This study compared four extraction methods for hop-derived compounds in beer late hopped with Nelson Sauvin. Extraction capacity and variation were compared for headspace solid phase micro extraction, stir bar sorptive extraction, headspace sorptive extraction, and solvent assisted flavour evaporation...
September 9, 2017: Journal of Separation Science
Jitka Caslavska, Wolfgang Thormann
Work dealing with the monitoring of transferrin isoforms in human serum and other body fluids by capillary electrophoresis is reviewed. It comprises capillary zone electrophoresis and capillary isoelectric focusing efforts that led to the exploration and use of assays for the determination of carbohydrate-deficient transferrin as marker for excessive alcohol intake, genetic variants of transferrin, congenital disorders of glycosylation and β-2-transferrin, which is a marker for cerebrospinal fluid leakage...
September 8, 2017: Journal of Separation Science
Nani Wang, Qiaoyan Zhang, Hailiang Xin, Dan Shou, Luping Qin
A method using osteoblast membrane chromatography coupled with liquid chromatography and time-of-flight mass spectrometry was developed to recognize and identify the specific active components from traditional Chinese medicines. Primary rat osteoblasts were used for the preparation of the stationary phase in the cell chromatography method. Retention components from the cell chromatography were collected and analyzed by liquid chromatography with time-of-flight mass spectrometry. This method was applied in screening active components from extracts of four traditional Chinese medicines...
September 8, 2017: Journal of Separation Science
Alexander Schriewer, Cristina Cadenas, Heiko Hayen
Cofactors such as coenzyme A and its derivatives acetyl-coenzyme A and malonyl-coenzyme A are involved in many metabolic pathways. Due to trace level concentrations in biological samples and the high reactivity of cofactors, a fast, sensitive and selective method for quantification is mandatory. In this study, online solid-phase extraction was coupled successfully to hydrophilic interaction liquid chromatography with tandem mass spectrometry for analytes' isolation in complex matrix and quantification by external calibration...
September 6, 2017: Journal of Separation Science
Xiong Shen, Jian Liang, Luxia Zheng, Qianzhou Lv, Hong Wang
A simple and sensitive method for the simultaneous determination of eight parabens in human plasma and urine samples was developed. The samples were preconcentrated using dispersive liquid-liquid microextraction based on the solidification of floating organic drops and determined by high-performance liquid chromatography with UV detection. The influence of variables affecting the extraction efficiency was investigated and optimized using Placket-Burman design and Box-Behnken design. The optimized values were: 58 μL of 1-decanol (as extraction solvent), 0...
September 6, 2017: Journal of Separation Science
Datong Wu, Pengfei Cai, Xiaoyong Zhao, Yong Kong, Yuanjiang Pan
Ionic liquids have been functionalized for modern applications. The functional ionic liquids are also called task-specific ionic liquids. Various task-specific ionic liquids with certain groups have been constructed and exploited widely in the field of separation. To take advantage of their properties in separation science, task-specific ionic liquids are generally used in techniques such as liquid-liquid extraction, solid-phase extraction, gas chromatography, high-performance liquid chromatography and capillary electrophoresis...
September 6, 2017: Journal of Separation Science
Jolanta Flieger, Hanna Trębacz, Magdalena Pizoń, Anna Kowalska, Agnieszka Szczęsna, Tomasz Plech
Basic thermodynamic functions responsible for retention of new 1,2,4-triazole derivatives exhibiting varied antiepileptic activity on cholesterol-based stationary phase were determined. Evaluation of the Gibbs energy change, the change in enthalpy and the change in entropy was based on the van 't Hoff relationship representing ln k vs. 1/T. A detailed discussion of the van 't Hoff equation, exploring the influence of the phase ratio on deviations from linearity in a Van 't Hoff plot is presented. We show chromatographic evidence to the question of how a varied mobile phase composition may cause different thermodynamic phase ratios...
September 4, 2017: Journal of Separation Science
Lei Chen, Meng Mei, Xiaojia Huang
A simple and sensitive method for the simultaneous extraction and determination of six aminoglycosides in honey and milk samples has been developed using multiple monolithic fiber solid-phase microextraction and liquid chromatography with tandem mass spectrometry. The multiple monolithic fibers based on poly (methacrylic acid-co-ethylenedimethacrylate) monolith as extractive medium was used to concentrate target analytes. Because there were abundant carboxyl groups in the monolith, the monolithic fibers could extract aminoglycosides effectively through cation-exchange and hydrophobic interactions...
September 4, 2017: Journal of Separation Science
Yimin Zhang, Zhiyong Chen, Xiaokun Xu, Qiang Zhou, Xiaolong Liu, Liping Liao, Zijia Zhang, Zhengtao Wang
Psoraleae Fructus is one of the most popular traditional Chinese medicines. Coumarins, flavonoid and meroterpenes are the main contributors to the biological activity of Psoraleae Fructus. In this study, a new method for the quality control of Psoraleae Fructus was developed, through the quantitative analysis of multi-components by single marker with diode array detector. Thirteen components, including psoralenoside, isopsoralenoside, psoralen, isopsoralen, psoralidin, neobavaisoflavone, bavachin, corylin, isobavachalcone, corylifol A, bavachinin, bavachalcone and bakuchiol were rapidly separated and identified within 12 min by the newly developed method...
September 4, 2017: Journal of Separation Science
Congcong Xu, Bing Wang, Yiqiong Pu, Jiansheng Tao, Tong Zhang
Triterpenes are a major class of chemical compounds found in natural plants and can be categorized into acyclic triterpenoids, monocyclic triterpenoids, tricyclic triterpenoids, tetracyclic triterpenoids, and pentacyclic triterpenoids. Among them, pentacyclic triterpenoids have gained more extensive attention due to their biological activities, including anti-inflammation, antibacterial, antioxidation, antitumor, anti-HIV, hepatoprotection, and immunological adjuvant properties. In this review we summarize the extraction and analytical methods for pentacyclic triterpenoids, where more than 56 triterpenes from 49 kinds of plants were involved...
September 1, 2017: Journal of Separation Science
Ting Hu, Jin-Lan Zhang
Lipids, which have core functions in energy storage, signalling and biofilm structures, play important roles in a variety of cellular processes because of the great diversity of their structural and physiochemical properties. Lipidomics is the large-scale profiling and quantification of biogenic lipid molecules, the comprehensive study of their pathways and the interpretation of their physiological significance based on analytical chemistry and statistical analysis. Lipidomics will not only provide insight into the physiological functions of lipid molecules but will also provide an approach to discovering important biomarkers for diagnosis or treatment of human diseases...
August 31, 2017: Journal of Separation Science
Magdalena Skoczylas, Szymon Bocian, Tomasz Kowalkowski, Bogusław Buszewski
The surface excess adsorption isotherms of water, acetonitrile, and methanol from binary hydro-organic mobile phases were investigated on nine home-made stationary phases with chemically bonded amino acids, dipeptides, and tripeptides using the dynamic minor disturbance method. The stationary phases were modified by the following amino acids: glycine, alanine, phenylalanine, leucine, and aspartic acid. It allows investigating the influence of the type of immobilized amino acids, in particular their different side chains, on the solvent adsorption...
August 31, 2017: Journal of Separation Science
Lu Wang, Yanan Wu, Qi Bei, Kan Shi, Zhenqiang Wu
Flavonoids are the main active components in Psidium guajava leaves and have many multi-physiological functions. In this study, the flavonoid compositions were identified in the Psidium guajava leaves samples using a high-performance liquid chromatography with time-of-flight electrospray ionization mass spectrometry method. A high-performance liquid chromatography fingerprint method, combined with chemometrics, was used to perform a quality assessment of the Psidium guajava leaves samples. The eight identified flavonoid compounds including rutin, isoquercitrin, quercetin-3-O-β-d-xylopyranoside, quercetin-3-O-α-l-arabinopyranoside, avicularin, quercitrin, quercetin, and kaempferol were used as the chemical markers...
August 31, 2017: Journal of Separation Science
Jinyang Fang, Bo Yang, Zhiwei Ge, Xue Bai, Binjun Yan
Xingnaojing Injection is a traditional Chinese medicine extensively used for stroke and cerebral ischemia. For better in-process quality control of Xingnaojing Injection, a method for the analysis of its intermediate (i.e., the distillate of Fructus Gardeniae and Radix Curcumae) is needed to monitor and optimize the hydrodistillation extraction process. In this work, nine major volatile components in the intermediate were identified: isophorone, 4-methylene-isophorone, curcumenone, curcumenol, curdione, curzerenone, furanodienone, curcumol, and germacrone...
August 31, 2017: Journal of Separation Science
Jing Wang, Dongfang Shi, Meizhu Zheng, Bing Ma, Jing Cui, Chunming Liu, Chengyu Liu
Natural products have become one of the most important resources for discovering novel xanthine oxidase inhibitors, which are commonly employed in the treatment of hyperuricemia and gout. However, to date, few reports exist regarding the use of monoterpene glycosides as xanthine oxidase inhibitors. Thus, we herein report the use of ultrafiltration coupled with liquid chromatography in the screening of monoterpene glycoside xanthine oxidase inhibitors from the extract of Paeonia lactiflora (P. lactiflora), and both high-performance counter-current chromatography and medium-pressure liquid chromatography were employed to separate the main constituents...
August 30, 2017: Journal of Separation Science
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