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Journal of Separation Science

Limeng Zhuo, Jingjing Peng, Yunli Zhao, Dongxiang Li, Xiuman Xie, Ling Tong, Zhiguo Yu
Traditional Chinese medicine consists of complex phytochemical constituents. Selecting appropriately analytical markers of traditional Chinese medicine is a critical step in quality control. Currently, the combination of fingerprinting and efficacy evaluation is considered as a useful method for screening active ingredients in complex mixtures. This study was designed to develop an orthogonal partial least squares model for screening bioactive quality control markers of QishenYiqi dripping pills based on the fingerprint-efficacy relationship...
August 12, 2017: Journal of Separation Science
Se Young Han, Kyung Min Jeong, Da Eun Yoo, Yan Jin, Eun Mi Kim, Su Hyun Kim, Seok-Yong Lee, Se-Hyung Kim, Jing Zhao, Jeongmi Lee
A readily applicable method was developed to determine the concentration level of zaltoprofen, a non-steroidal anti-inflammatory drug from the propionic acid family, in human plasma. This method is based on manual shaking-assisted dispersive liquid-liquid microextraction coupled with liquid chromatography with UV detection. Factors affecting the extraction efficiency were screened and optimized by experimental design using fractional factorial and central composite designs, respectively. Optimal conditions were: 220 μL of C2 H4 Cl2 (extraction solvent), 5 mL of 3...
August 12, 2017: Journal of Separation Science
Julie R McGettrick, Christopher P Palmer
Capillary electrophoresis and electrokinetic chromatography are typically carried out in unmodified fused silica capillaries under conditions that result in a strong negative zeta potential at the capillary wall and a robust cathodic electroosmotic flow. Modification of the capillary wall to reverse the zeta potential and mask silanol sites can improve separation performance by reducing or eliminating analyte adsorption, and is essential when conducting electrokinetic chromatography separations with cationic latex nanoparticle pseudo-stationary phases...
August 12, 2017: Journal of Separation Science
Chan Jin, Jibin Guan, Dong Zhang, Bing Li, Hongzhuo Liu, Zhonggui He
We present a technique to rapid determine taxane in blood samples by supercritical fluid chromatography together with mass spectrometry. The aim of this study was to develop a supercritical fluid chromatography with mass spectrometry method for the analysis of paclitaxel, cabazitaxel and docetaxel in whole-blood samples of rats. Liquid-dry matrix spot extraction was selected in sample preparation procedure. Supercritical fluid chromatography separation of paclitaxel, cabazitaxel, docetaxel and glyburide (internal standard) was accomplished within 3 min by using the gradient mobile phase consisted of methanol as the compensation solvent and carbon dioxide at a flow rate of 1...
August 11, 2017: Journal of Separation Science
Amir Shamloo, Ali Kamali
In this study, a dielectrophoresis field-flow fractionation device was analyzed using a numerical simulation method and the behaviors of a set of different cells were investigated. By reducing the alternating current frequency of the electrodes from the value used in the original setup configuration and increasing the number of exit channels, total discrimination in cell trajectories and subsequent separation of four cell types were achieved. Cells were differentiated based on their size and dielectric response which are represented in their real part of Clausius-Mossotti factor at different frequencies...
August 10, 2017: Journal of Separation Science
Lin Hao, Jiayi Wei, Ruixue Zheng, Chun Wang, Qiuhua Wu, Zhi Wang
Metal-organic frameworks-5 (MOF-5) was explored as a template to prepare porous carbon due to its high surface area, large pore volume, and permanent nanoscale porosity. Magnetic porous carbon, Co@MOF-5-C, was fabricated by the one-step direct carbonization of Co-doped MOF-5. After carbonization, the magnetic cobalt nanoparticles are well dispersed in the porous carbon matrix, and Co@MOF-5-C displays strong magnetism (with the saturation magnetization intensity of 70.17emu g(-1) ), high specific surface area, and large pore volume...
August 10, 2017: Journal of Separation Science
Roman Kaliszan, Małgorzata Waszczuk-Jankowska, Danuta Siluk, Bartosz Wielgomas
It was sensation when Dr. J. Beneviste reported alleged experimental biological evidence of the water memory effect (E. Dayenas et al. Nature 333, 816-818, 1988; These experiments have never been reproduced in controlled conditions, however. Instead, the hypothesis that water can be imprinted with the memory of past solutes was ruled out (J. Maddox et al. Nature 334, 287-290, 1988; At present, so-called "molecular imprinting" is a technology of preparing polymer matrices as affinity-based analyte separation media (J...
August 10, 2017: Journal of Separation Science
Mingfang Wang, Yuerong Wang, Pei Luo, Hongyang Zhang, Min Zhang, Ping Hu
The content of styrene units in non-hydrogenated and hydrogenated styrene-butadiene-styrene and styrene-isoprene-styrene triblock copolymers significantly influences product performance. A size exclusion chromatography method was developed to determine the average styrene content of triblock copolymers blended with tackifier in adhesives. A complete separation of the triblock copolymer from the other additives was realized with size exclusion chromatography. The peak area ratio of the UV and refraction index signals of the copolymers at the same effective elution volume was correlated to the average styrene unit content using NMR spectroscopy with commercial copolymers as standards...
August 10, 2017: Journal of Separation Science
Qingxiang Zhou, Yongyong Yuan, Yalin Wu, Yongli Liu
A novel magnetic core-shell material polyaniline@SiO2@Fe (PANI@SiO2@Fe) has been successfully synthesized and investigated as an effective adsorbent for the magnetic solid-phase extraction of typical endocrine disrupting compounds such as bisphenol A, tetrabromobisphenol A and 4-nonylphenol from water samples. The morphology of the as-prepared PANI@SiO2@Fe was characterized by transmission electron microscopy and X-ray diffraction. The main parameters that influenced the enrichment performance such as the kind of eluent, amount of adsorbent, volume of eluent, adsorption time, elution time, ionic strength, pH, concentration of humic acid and sample volume were investigated...
August 9, 2017: Journal of Separation Science
Yuxin Ma, Lingling Liu, Weiyang Tang, Tao Zhu
Sulfonated poly(styrene-divinylbenzene) modified with five kinds of amine functional groups had been efficiently applied to the determination of carbendazim in apple samples with pipette-tip solid-phase extraction method. The structures of the polymers were characterized by scanning electron microscopy, FTIR spectroscopy and thermogravimetric analysis. Five different modifications of the solid-phase extraction sorbent based on sulfonated poly(styrene-divinylbenzene) were tested under static and pipette-tip solid-phase extraction conditions...
August 9, 2017: Journal of Separation Science
Niels van Boxtel, Kris Wolfs, Marta Guillén Palacín, Ann Van Schepdael, Erwin Adams
To discourage consumption, ethanol is often denatured using both volatile (e.g. methyl ethyl ketone and isopropanol) and non-volatile (e.g. denatonium benzoate) chemical substances. As a result, the analysis of denatured ethanol samples is usually performed by multiple techniques such as gas chromatography for the volatile denaturants and liquid chromatography for the non-volatile ones. However, the need for multiple techniques increases the cost of analysis and forms a severe obstruction for on-site product control...
August 9, 2017: Journal of Separation Science
Shengnan Duan, Wen Qi, Siwen Zhang, Kunkun Huang, Dan Yuan
An ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry method in both positive and negative ion modes was established in order to comprehensively investigate the major constituents in Wu-Ji-Bai-Feng-Pill. Briefly, a Waters ACQUITY UPLC HSS C18 column was used to separate the aqueous extract of Wu-Ji-Bai-Feng-Pill. 0.1% formic acid in acetonitrile and 0.1% aqueous formic acid v/v were used as the mobile phase. All analytes were determined using quadrupole time-of-flight mass spectrometry with electrospray ionization source in positive and negative ion modes...
August 9, 2017: Journal of Separation Science
Hong Wan, Bo Zhang, Xiao-Lin Bai, Yan Zhao, Meng-Wei Xiao, Xun Liao
A new, rapid, green, and cost-effective magnetic solid-phase extraction of ochratoxin A from red wine samples was developed using polydopamine-coated magnetic multi-walled carbon nanotubes as the absorbent. The polydopamine-coated magnetic multi-walled carbon nanotubes were fabricated with magnetic multi-walled carbon nanotubes and dopamine by an in situ oxidative self-polymerization approach. Transmission electron microscopy, dynamic light scattering, X-ray photoelectron spectroscopy and vibrating sample magnetometry were used to characterize the absorbents...
August 7, 2017: Journal of Separation Science
Tiziana Nardin, Chiara Barnaba, Franco Abballe, Gianmaria Trenti, Mario Malacarne, Roberto Larcher
A fast separation based on cation-exchange liquid chromatography coupled with high-resolution mass spectrometry is proposed for simultaneous determination of chlormequat, difenzoquat, diquat, mepiquat and paraquat in several food and beverage commodities. Solid samples were extracted using a mix of water/methanol/formic acid (69.6:30:0.4 v/v/v), while liquid samples were ten-times diluted with the same solution. Separation was carried out on an experimental length-modified IonPac CS17 column (2 × 15 mm) which allowed the use of formic acid and acetonitrile as mobile phase...
August 5, 2017: Journal of Separation Science
Saeed Nojavan, Mahsa Sirani, Sakine Asadi
In this study, electromembrane extraction from a flowing sample solution, termed continuous-flow electromembrane extraction, was developed and compared with conventional procedures for the determination of four basic drugs in real samples. Experimental parameters affecting the extraction efficiency were further studied and optimized. Under optimum conditions, linearity of continuous flow procedure was within 8.0-500 ng mL(-1) , while it was wider for conventional procedures (2.0-500 ng mL(-1) ). Moreover, repeatability (%RSD) was found to range between 5...
August 5, 2017: Journal of Separation Science
Edyta Nalewajko-Sieliwoniuk, Julita Malejko, Paulina Twarowska, Magdalena Timoszuk, Jolanta Nazaruk
Novel methods for the determination of polyphenolic antioxidants present in extracts from inflorescences of Cirsium vulgare (Savi) Ten. based on ultra high performance liquid chromatography with photodiode array and chemiluminescence detection have been developed. Under the optimized conditions of chromatographic separation the analytical characteristic of the method was performed. The proposed method was successfully applied to the determination of ten polyphenols present in inflorescences of Cirsium vulgare...
August 5, 2017: Journal of Separation Science
Rune Graesbøll, Hans-Gerd Janssen, Jan H Christensen, Nikoline J Nielsen
The linear solvent strength model was used to predict coverage in online comprehensive two-dimensional reversed-phase liquid chromatography. The prediction model uses a parallelogram to describe the separation space covered with peaks in a system with limited orthogonality. The corners of the parallelogram are assumed to behave like chromatographic peaks and the position of these pseudo-compounds predicted. A mix of 25 polycyclic aromatic compounds were used as a test. The precision of the prediction, span 0-25, was tested by varying input parameters, and was found to be acceptable with root mean square errors of 3...
August 3, 2017: Journal of Separation Science
Katarzyna Tyśkiewicz, Agnieszka Dębczak, Roman Gieysztor, Tomasz Szymczak, Edward Rój
Vitamins are compounds that take part in all basic functions of an organism but also are subject of number of studies performed by different researchers. Two groups of vitamins are distinguished taking into consideration their solubility. Chromatography with supercritical CO2 has found application in determination, separation and quantitative analyses of both fat- and water-soluble vitamins. The methods of vitamins separation have developed and improved throughout the years. Both groups of compounds were separated using supercritical fluid chromatography with different detection on different stationary phases...
August 3, 2017: Journal of Separation Science
Wilmer H Perera, Ion Ghiviriga, Douglas L Rodenburg, Raquel Carvalho, Kamilla Alves, James D McChesney
As an aid for structure elucidation of new steviol glycosides, reversed-phase C18 high-performance liquid chromatography method was developed with several previously characterized diterpene glycosides, to identify known and detect novel aglycone-C13 oligosaccharide moieties and indirectly identify C-19 interlinkages. Elution order of several diterpene glycosides and their aglycone-C13 oligosaccharide substituted with different sugar arrangements were also summarized. Comparison of the retention time of a product obtained after alkaline hydrolysis with the alycone-C-13 portions of known compounds reported herein allowed us to deduce the exact positions of the sugars in the C-13 oligosaccharide portion...
August 1, 2017: Journal of Separation Science
Mariosimone Zoccali, Daniele Giuffrida, Paola Dugo, Luigi Mondello
Recently, supercritical fluid chromatography coupled to mass spectrometry has gained attention as a fast and useful technology applied to the carotenoids analysis. However no reports are available in the literature on the direct on-line extraction and determination, by supercritical fluid extraction with chromatography and mass spectrometry. The aim of this research was focused on the development of an online method coupling supercritical fluid extraction and supercritical fluid chromatography for a detailed targeted native carotenoids characterization in red habanero peppers...
July 31, 2017: Journal of Separation Science
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