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Journal of Separation Science

Cristina Cruz-Hernandez, Sagar K Thakkar, Isabelle Masserey-Elmelegy, William Bousi, Patric Fontannaz, Francesca Giuffrida
As a result of the heterogeneous nature of lipid classes in complex biological matrices such as plasma and erythrocytes, it is imperative to have a robust and validated methodology for fatty acid quantification. The effective method presented here combines available methodology of fast gas chromatography and an improvement of the sample preparation methodology before injection into the gas chromatograph. This methodology ensures complete transesterification and quantification of total and individual fatty acids (and not only in relative amounts) by addition of internal standards...
June 21, 2017: Journal of Separation Science
B L Abhijith, Moolya Mohan, David Joseph, Simimole Haleema, Hassan Y Aboul-Enein, Ibrahim Ibnusaud
A simple capillary zone electrophoresis method with direct ultraviolet detection has been developed for the analysis of naturally occurring diastereomeric 2-hydroxycitric acid lactones. Using 50 mM sodium phosphate buffer of pH 7, a baseline resolution Rs > 3.0 was observed for all organic acids selected for the present study. This method was employed for the quantitative determination of title acids present in the plant sources namely G. cambogia fruit rinds and H. sabdariffa calyx. Conversion of 2-hydroxycitric acids to their lactones on heating above plant sources is deliberated...
June 21, 2017: Journal of Separation Science
Wenying Wu, Yu Chen, Binjie Wang, Xiaoyang Sun, Ping Guo, Xiaohui Chen
Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography with mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform-ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkyne, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furan, pyrrole, acid amide, heterocycle and oxide were detected from Baidianling Capsule by gas chromatography with mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index...
June 20, 2017: Journal of Separation Science
Abolghasem Jouyban, Samin Hamidi
A dispersive micro solid phase extraction procedure coupled with CE-UV detection was developed for determination of verapamil in plasma samples. Graphene oxide/polydopamin was synthesized by a one-step polymerization method, and graphene oxide/Fe3 O4 nanocomposite was prepared by co-precipitation method. Moreover, they were fully characterized. The use of hazardous and water-immiscible solvents was scaled down, and only 500 μL of acetone was required as the desorption solvent. The detector response-concentration plots were linear in the range of 5-500 ng/mL, and the proposed method was validated according to guidelines...
June 20, 2017: Journal of Separation Science
Wanwan Ma, Tangand Baokun, Kyung Ho Row
A methyltriphenylphosphonium bromide/chalcone/formic acid as a green ternary deep eutectic solvent was applied as a functional monomer and dummy template simultaneously in the synthesis of a new molecularly imprinted polymer. Ternary deep eutectic solvent based molecularly imprinted polymers were used as a solid-phase extraction sorbent in the separation and purification of rutin and quercetin from Herba Artemisiae Scopariae combined with high-performance liquid chromatography. FTIR spectroscopy and field-emission scanning electron microscopy were applied to characterize the deep eutectic solvent based molecularly imprinted polymers synthesized using different molar ratios of chalcone...
June 20, 2017: Journal of Separation Science
Yonghua Wang, Min Rui, Guanghua Lu
Metal-organic frameworks are promising materials in diverse analytical applications especially in sample pretreatment by virtue of their diverse structure topology, tunable pore size, permanent nanoscale porosity, high surface area and good thermostability. According to hydrostability, metal-organic frameworks are divided into moisture-sensitive and water-stable types. In the actual application, both kinds of metal organic frameworks are usually engineered into hybrid composites containing magnetite, silicon dioxide, graphene or directly carbonized to metal-organic-frameworks-derived carbon...
June 19, 2017: Journal of Separation Science
Hongyan Zhao, Yizhou Wang, Heyong Cheng, Yuanchao Wang
Single-walled carbon nanohorns have received great interest for their unique properties and diverse potential applications. Herein, we demonstrated the feasibility of a single-walled carbon nanohorns incorporated poly(styrene-divinylbenzene) monolith as the stationary phase for capillary electrochromatography, which was prepared by one-step in situ copolymerization. Single-walled carbon nanohorns were dispersed in styrene to give a stable and homogeneous suspension. The monolithic column gave effective separation for a wide range of aromatic compounds, which was based on hydrophobicity and π-π electrostatic stacking of single-walled carbon nanohorns...
June 19, 2017: Journal of Separation Science
Rong Yi, Sarah Zhao, Noel Kong, Julia Zhang, Devan Loganathan, Sandrine Mérette, Barbara Morrissey
γ-Aminobutyric acid is the principal inhibitory neurotransmitter in the central nervous system and regulates the neuronal excitability. There has been anecdotal evidence that γ-aminobutyric acid has been used within a few hours prior to competition in equine sports to calm down nervous horses. However, regulating the use of γ-aminobutyric acid is challenging because it is an endogenous substance in the horse. γ-Aminobutyric acid is usually present at low ng/mL levels in equine plasma; therefore, a sensitive method has to be developed to quantify these low background levels...
June 19, 2017: Journal of Separation Science
Jingqing Mu, Xun Gao, Qing Li, Xiaomei Yang, Wenling Yang, Xu Sun, Kaishun Bi, Huifen Zhang
Guanxin Shutong Capsule, an effective traditional Chinese medicine, is widely used for coronary heart disease clinically. Volatile components are one of its important bioactive constituents. To better understand the material basis for the therapeutic effects, the components of Guanxin Shutong Capsule absorbed into the blood and their metabolites were identified based on gas chromatography with mass spectrometry coupled with vortex-ultrasound-assisted dispersive liquid-liquid microextraction. As a result, three prototypes and 15 metabolites were identified or tentatively characterized in rat plasma...
June 19, 2017: Journal of Separation Science
Gyula Lajkó, Tímea Orosz, Imre Ugrai, Zsolt Szakonyi, Ferenc Fülöp, Wolfgang Lindner, Antal Péter, István Ilisz
The eight stereoisomers of limonene-based carbocyclic β-amino acids containing three chiral centers have been directly separated on chiral stationary phases containing Cinchona alkaloid-based zwitterionic selectors. The effects of bulk solvent composition of the mobile phase, the nature of base additives, counter-ion concentration, and the structure of selector on the enantiorecognition were studied. Experiments were performed at constant mobile phase composition in the temperature range 5-40°C to study the effect of temperature...
June 16, 2017: Journal of Separation Science
Jing Li, Si Hun Roh, Jia Shaodong, Ji Yeon Hong, Dong-Kyu Lee, Byong-Kyu Shin, Jeong Hill Park, Jeongmi Lee, Sung Won Kwon
A novel analytical method for the simultaneous determination of the concentration of sildenafil and its five analogues in dietary supplements using solid-phase-extraction-assisted reversed-phase dispersive liquid-liquid microextraction based on solidification of floating organic droplet combined with ion-pairing liquid chromatography with an ultraviolet detector was developed. Parameters that affect extraction efficiency were systematically investigated, including the type of solid-phase extraction cartridge, pH of the extraction environment and the type and volume of extraction and dispersive solvent...
June 15, 2017: Journal of Separation Science
Long Pang, Peijie Yang, Rong Pang, Shunyi Li
1-hexadecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is a solid-phase ionic organic material under ambient temperature, and is considered as a kind of "frozen" ionic liquid. Because of their solid-state and ultra-hydrophobicity, "frozen" ionic liquids are able to be confined in the pores of hollow fiber, based on which a simple method was developed for the hollow-fiber solid-phase microextraction of dichlorodiphenyltrichloroethane and its main metabolites. Under optimized conditions, the proposed method results in good linearity (R(2) > 0...
June 15, 2017: Journal of Separation Science
Dzema Daria, Kartsova Liudmila, Emelianov Gennady
Highly fluorinated polymers are promising materials in separation methods due to combination of high chemical and thermally stability, hydro- and oleophobicity and weak intermolecular forces. However, application of these polymers in chromatography is limited because of their low solubility in aqueous-organic solvents. In our research, the highly fluorinated water soluble polymers with -SO3(-) N(Et)4(+) , -SO2 NH2 and -N(Et)2 terminal groups were synthesized and applied as additives to the background electrolyte for the separation of steroid hormones and proteins by capillary electromigration methods...
June 15, 2017: Journal of Separation Science
Bichao Yang, Huaxia Xin, Feier Wang, Jianfeng Cai, Yanfang Liu, Qing Fu, Yu Jin, Xinmiao Liang
As a common traditional Chinese medicine, Fructus Arctii has important clinical medical values. Its main components are lignans, which are difficult to separate and analyze because of the complex composition, similar chemical structures, and close properties. In this study, an off-line two-dimensional supercritical fluid chromatography/reversed-phase liquid chromatography method as well as an effective sample pretreatment method based on hydrophilic interaction chromatography material was developed to enrich the minor lignan fractions and obtain high-purity compounds...
June 15, 2017: Journal of Separation Science
Minghui Meng, Zeying He, Yaping Xu, Lu Wang, Yi Peng, Xiaowei Liu
The increasing use of antibiotics has caused substantial environmental problems, which proved to be a matter of great concern. The aim of this work was to develop a quick, easy, cheap, effective, rugged and safe method for 20 antibiotics residues in soil. The developed method was based on extraction with acetonitrile and phosphate buffer, clean-up with dispersive solid-phase extraction adsorbent using primary secondary amine, octadecylsilane, followed by liquid chromatography with tandem mass spectrometry determination...
June 13, 2017: Journal of Separation Science
Yifeng Zeng, Liang Luo, Waner Hou, Biyu Lu, Jing Gong, Jiahui Chen, Xiaojun Zhang, Bo Han, Zhiyong Xie, Qiongfeng Liao
Gut microbiota-host co-metabolites are closely related to various diseases. Monitoring dynamic changes of co-metabolites can provide a more comprehensive understanding of pathophysiology. Here, a novel liquid chromatography-tandem mass spectrometry method was performed for the analysis of aromatic amino acids and their gut microbiota-host co-metabolites in rat serum and urine. In the developed method, seven key gut microbiota-host co-metabolites were chromatographically separated on a Kinetex Phenyl-Hexyl column by gradient elution, and the run time was 6 min...
June 12, 2017: Journal of Separation Science
Alexander Brandis, Eran Partouche, Tamar Yechezkel, Yoseph Salitra, Vladimir Shkoulev, Avigdor Scherz, Flavio Grynszpan
A practical and relatively simple method to identify molecularly imprinted polymers capable of binding proteins via the molecular tagging (epitope-like) approach has been developed. In our two step method we first challenge a previously obtained anti-tag molecularly imprinted polymer with a small molecule including the said tag of choice (a biotin derivative as shown here or other) connected to a linker bound to a second biotin moiety. An avidin molecule partially decorated with fluorescent labels is then allowed to bind the available biotin derivative associated to the polymer matrix...
June 12, 2017: Journal of Separation Science
Xin-Jie Wang, Zhen-Lin Li, Xu-Hui Lv, Qi-Yan Zuo, Yan-Min Zhao, Yong-Fang Ding, She-Ban Pu, Shi-Hui Qian, Yun-Ru Peng
The root of Cynanchum auriculatum (C. auriculatum) Royle ex Wight has been shown to possess various pharmacological effects and has recently attracted much attention with respect to the potential role in antitumor activity. The C-21 steroidal glycosides were commonly accepted as the major active ingredients of C. auriculatum. In this study, the antitumor abilities of different extracted-fractions of the root bark and the root tuber of C. auriculatum were investigated by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in human cancer cell lines HepG2 and SMMC-7721...
June 8, 2017: Journal of Separation Science
Lingfei Han, Desheng Hou, Congyu Ma, Na Fu, Jing Liu, Feng Feng, Wenyuan Liu, Feng Zheng
Short-chain aliphatic amines are a class of hazardous impurities in drug substances. A simple method, involving derivatization followed by high-performance liquid chromatography with diode array detection, has been developed for residue determination of eight aliphatic amines simultaneously in drug substances. Different halonitrobenzenes derivatization reagents were systematically compared. As a result, 1-fluoro-2-nitro-4-(trifluoromethyl)benzene was selected since the derivatization effectively shifted the absorption wavelength to the visible region (400-450 nm), where most drug substances, impurities and even the derivatization reagent absorb very weakly...
June 8, 2017: Journal of Separation Science
Jianhao Wang, Yaqin Gu, Li Liu, Cheli Wang, Jianpeng Wang, Shumin Ding, Jinping Li, Lin Qiu, Pengju Jiang
The dynamic binding status between the thrombin and its G-quadruplex aptamers and the stability of its interaction partners were probed using our previously established fluorescence-coupled capillary electrophoresis method. A 29-nucleic acid thrombin-binding aptamer was chosen as a model to study its binding affinity with the thrombin ligand. Firstly, the effects of the cations on the formation of G-quadruplex from unstructured 29-nucleic acid thrombin-binding aptamer were examined. Secondly, the rapid binding kinetics between the thrombin and 6-carboxyfluorescein labeled G-quadruplex aptamer was measured...
June 8, 2017: Journal of Separation Science
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