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Journal of Separation Science

Tamara Alvarez-Segura, Carolina Camacho-Molinero, José Ramón Torres-Lapasió, M Celia García-Alvarez-Coque
Single conventional columns in reversed-phase LC are insufficient for analysing the isoindoles of primary amino acids, due to their limited functionality. An interesting possibility for increasing the separation power is the combination of several columns of different nature, where the length is modified by coupling small segments. This approach may require a considerable investment to have multiple lengths for each stationary phase. However, the combination of only two columns of fixed length can be enough to resolve satisfactorily relatively complex mixtures, provided that an optimised gradient program is applied...
May 18, 2017: Journal of Separation Science
Yanhui Ge, Pengqi Guo, Xinya Xu, Guoning Chen, Xuemei Zhang, Hua Shu, Bilin Zhang, Zhimin Luo, Chun Chang, Qiang Fu
In this study, surface molecularly imprinted polymers were prepared as the selective sorbents for separation of aristolochic acid I in herbal medicine extracts by a facile approach. A less toxic dummy-template, ofloxacin, was used to create specific molecule recognition sites for aristolochic acid I in the synthesized polymers. The polymers were characterized by Fourier-transfer infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, elemental analysis and nitrogen adsorption-desorption test...
May 18, 2017: Journal of Separation Science
Shuai Chen, Guoxiang Sun, Lanping Yang, Jing Zhang
An approach combining micellar electrokinetic chromatography (MEKC) fingerprinting with chemometrics was developed to evaluate the quality consistency of Lianqiao Baidu pills (LQDBPs), which are a traditional Chinese patent medicine composed of nineteen herbs used mainly to treat skin ulcers, the common cold, rheumatism, herpes, and constipation. The triangle optimization method was employed to choose a satisfactory background electrolyte, with the information index, I, as an objective function for assessing the capillary electrophoresis conditions...
May 18, 2017: Journal of Separation Science
Mohammad Bazregar, Maryam Rajabi, Yadollah Yamini, Alireza Asghari
In this work, an efficient sample clean-up method named in-tube electro-membrane extraction is modified to resolve the formation of bubbles in the extraction process. This modified method is applied for the extraction of two model analytes including tartrazine and sunset yellow from food samples. The method is based upon the electro-kinetic migration of ionized compounds by the application of an electrical potential difference, and on this basis, the analytes under investigation, as anionic compounds, simply migrate from the donor phase, and are concentrated in the acceptor phase...
May 17, 2017: Journal of Separation Science
Kyle B Lynch, Apeng Chen, Yu Yang, Joann J Lu, Shaorong Liu
This paper discusses the construction and performance of a HPLC cartridge we have developed that resulted from a culmination of previous research. We have recently developed an innovative approach to creating gradient elutions through the use of dual electroosmotic pumps and a series of three valves. This method has been proved to be the most reproducible and robust in producing gradients compared to our previously tested methods. Through the use of this approach, we have assembled a HPLC cartridge powered and controlled via a computer...
May 17, 2017: Journal of Separation Science
Shuang Hu, Xiao Yang, Jiao Xue, Xuan Chen, Xiao-Hong Bai, Zhi-Hui Yu
A novel graphene/dodecanol floating solidification microextraction followed by HPLC with diode-array detection has been developed to extract trace levels of four cinnamic acid derivatives in traditional Chinese medicines. Several parameters affecting the performance were investigated and optimized. Also, possible microextraction mechanism was analyzed and discussed. Under the optimum conditions (amount of graphene in dodecanol: 0.25 mg/mL; volume of extraction phase: 70 μL; pH of sample phase: 3; extraction time: 30( ) min; stirring rate: 1000 rpm; salt amount: 26...
May 17, 2017: Journal of Separation Science
Junhui Chen, Yanlong Wang, Lei Pan, Huihui Shen, Dan Fu, Boqiang Fu, Chengjun Sun, Li Zheng
A novel method was developed for the purification of two typical diarrhetic shellfish poisoning toxins from toxin-producing marine microalgae using macroporous resin, high-speed counter-current chromatography-mass spectrometry, and semi-preparative high-performance liquid chromatography-mass spectrometry (HPLC-MS). Analytical HPLC-MS was used for identification and purity analysis of okadaic acid and dinophysistoxin-1 because they exhibit no visible or ultraviolet absorption. First, four kinds of macroporous resins were investigated, and HP-20 macroporous resin was selected for the pre-enrichment and cleanup of the two target toxins...
May 17, 2017: Journal of Separation Science
Imran Ali, Mohd Suhail, Leonid Asnin
The quinolones are derivatives of oxoquinolines and mostly known for their antibacterial and antiviral activities. Many quinolones are chiral compounds having asymmetric centers and important due to their enantioselective biological activities. In order to study the biological activities of quinolone enantiomers, to control the manufacturing of homochiral drugs and to prepare necessary quantities of pure enantiomers for pre-clinical or clinical trials, respective chiral separation methods are urgently needed...
May 16, 2017: Journal of Separation Science
Qing Wang, Zhiwei Lu, Li Zhang, Qingqing Zhang, Meiling Wang, Huizhen Zhao, Yuehong Liu, Shuang Fu, Zhenghai Huang, Ziye Xie, Honghong Yu, Zhixin Zhang, Xiaoyan Gao
Chemical characteristic fragment filtering in MS(n) chromatograms was proposed to detect and identify the components in rhubarb rapidly using high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry. Characteristic fragments consist of diagnostic ions and neutral loss fragments. Characteristic fragment filtering is a post-acquisition data mining method for the targeted screening of groups with specific structures, including three steps: first, in order to comprehensively summarize characteristic fragments for global identification of the ingredients in rhubarb, representative authentic standards of dominant chemical categories contained in rhubarb were chosen, from which fragmentation rules and a characteristic fragments schedule were proposed; second, characteristic fragment filtering was used to rapidly recognize analogous skeletons; finally, combined with retention time, accurate mass, characteristic fragments and previous literature, the structures of the filtered compounds were identified or tentatively characterized...
May 12, 2017: Journal of Separation Science
Yulei Cui, Na Shen, Jun Dang, Lijuan Mei, Yanduo Tao, Zenggen Liu
Bioactive equivalent combinatorial components play a critical role in herbal medicines. However, how to discover and enrich them efficiently is a desirable question for all the herbal pharmaceuticals researchers. In our work, a novel two-dimensional reversed-phase/hydrophilic interaction high-performance liquid chromatography method was established to perform real-time components trapping and combining for preparation and isolation of co-eluting components. A. kansuensis was taken as an example and solid-phase extraction coupled with liquid-liquid extraction as a simple and efficient method for enriching trace components, reversed phase column coupled with hydrophilic interaction liquid chromatography XAmide column as two-dimensional chromatography technology for isolation and preparation of co-eluting constituents, enzyme-linked immune-sorbent assay as bio-guided assay and anti-inflammatory bioactivity evaluation for bioactive constituents...
May 11, 2017: Journal of Separation Science
Shengnan Wang, Yujiao Hua, Ying Lin, Lisi Zou, Xunhong Liu, Ying Yan, Hui Zhao, Yiyuan Luo, Juanxiu Liu
Scrophulariae Radix is one of the most popular traditional Chinese medicines. The harvesting time of Scrophulariae Radix is closely related to the quality of products in this traditional Chinese medicine. The goal of the study is to analyze the dynamic changes of metabolite accumulation in Scrophulariae Radix. The difference of constituents in Scrophulariae Radix harvested at different times was analyzed by liquid chromatography with triple quadrupole-time of flight tandem mass spectrometry coupled with principal component analysis and partial least-square discriminant analysis...
May 11, 2017: Journal of Separation Science
Rui Su, Dan Li, Lijie Wu, Jing Han, Wenhui Lian, Keren Wang, Hongmei Yang
A novel microextraction method, termed microwave-assisted ionic liquid/ionic liquid dispersive liquid-liquid microextraction has been developed for the rapid enrichment and analysis of triazine herbicides in fruit juice samples by high-performance liquid chromatography. Instead of using hazardous organic solvents, two kinds of ionic liquids, a hydrophobic ionic liquid (1-hexyl-3-methylimidazolium hexafluorophosphate) and a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate), were used as the extraction solvent and dispersion agent, respectively, in this method...
May 11, 2017: Journal of Separation Science
Weiyu Zhai, Jianhua Liu, Qi Liu, Yumei Wang, Dezhu Yang
The root of Dictamnus dasycarpus Turcz., also known as Cortex Dictamni, is a Chinese herbal medicine commonly used in the treatment of inflammation, microbial infection, cancer and other diseases in China for thousands of years. Recently, the essential oil of Cortex Dictamni has been widely studied and a large number of volatile constituents have been discovered. However, the research of the essential oil of Cortex Dictamni in vivo remains unknown, especially the constituents absorbed into blood after oral administration...
May 11, 2017: Journal of Separation Science
Ting Zhou, Jing Zeng, Ting Zhao, Qisheng Zhong, Yang Yang, Wen Tan
In this study, an enantioselective analytical method based on microwave-assisted chiral derivatization coupled with ultra high performance liquid chromatography and tandem mass spectrometry was developed for the determination of bambuterol enantiomers in human plasma. The chiral derivatization reaction was greatly accelerated by microwave irradiation. Under the optimized conditions, both the derivatization time and separation time on column was only 3 min, and the lower limit of quantification was 2.5 pg mL(-1) ...
May 11, 2017: Journal of Separation Science
Xunlong Zhong, Yanmei Zhong, Kangqi Yan, Xuerong Xiao, Lian Duan, Ruolun Wang, Laiyou Wang
Er-Zhi-Pill, which consists of Ligustri lucidi fructus and Ecliptae prostratae herba, is a classical traditional Chinese medicinal formulation widely used as a liver-nourishing and kidney-enriching tonic. To identify the bioactive ingredients of Er-Zhi-Pill and characterize the variation of chemical constituents between codecoction and mix of individually decocted L. lucidi fructus and E. prostratae herba, a novel metabolomics approach based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry in both positive and negative ion modes, was established to comprehensively analyze chemical constituents and probe distinguishable chemical markers...
May 9, 2017: Journal of Separation Science
Zhe Yang, Guo-Xiang Sun
A fingerprint method was developed and combined with chemometrics for the quality evaluation of Tianma Toutong tablets, which are herbal medicine tablets used to treat migraine. Samples were analyzed by high-performance liquid chromatography, where five single-wavelength profiles (203, 232, 254, 280 and 310 nm) were fused to generate a five-wavelength fusion fingerprint and were also used for the quantitative analysis of seven chemical markers (gastrodin, caffeic acid, hesperidin, isoimperatorin, chlorogenic acid, ferulic acid and imperatorin)...
May 8, 2017: Journal of Separation Science
Jia-Ling Dai, Li-Hua Zhao, Jie-Hua Shi
1-Butyl-3-[(3-trimethoxysilyl)propyl]imidazolium chloride ionic liquid was synthesized and chemically modified onto the inner wall of a fused capillary column as a stationary phase for gas chromatography. The 1-butyl-3-[(3-trimethoxysilyl)propyl]imidazolium chloride ionic liquid bonded capillary column was evaluated in detail. The results revealed that the ionic liquid bonded capillary column exhibited high column efficiency of 1.08 × 10(4) plates/m, and good chromatographic separation selectivity (α) for polar and nonpolar substances, and a good thermal stability between room temperature and 400°C...
May 8, 2017: Journal of Separation Science
Ashraf Ali, Won Jo Cheong
A specially designed long open tubular capillary column (50 μm internal diameter and 112 cm effective length) was prepared by fabrication of a thin tri-component copolymer layer on the inner surface of silica capillary. A pretreated silica capillary was reacted with 4-(chloromethyl)phenyl isocyanate in the presence of dibutyltin dichloride as catalyst followed by sodium diethyl dithiocarbamate. Then a thin polymer layer was made on the inner surface of capillary by reversible addition-fragmentation transfer polymerization of styrene, N-phenylacrylamide, and methacrylic acid...
May 5, 2017: Journal of Separation Science
Miguel García-Fernández, Myriam Díaz-Álvarez, Antonio Martín-Esteban
The preparation of molecularly imprinted core-shell magnetic nanoparticles and their subsequent use in the solid-phase extraction of thiabendazole from citrus sample extracts is described. Molecularly imprinted core-shell magnetic nanoparticles were prepared by the precipitation copolymerization of the imprinting polymerization mixture on the surface of vinyl-modified silica magnetic nanoparticles and were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The obtained molecularly imprinted core-shell magnetic nanoparticles exhibited a high selectivity for thiabendazole and were easily collected and separated by an external magnetic field without additional centrifugation or filtration steps...
May 5, 2017: Journal of Separation Science
Rakesh Roshan Jha, Nivedita Singh, Rupender Kumari, Devendra Kumar Patel
Antibiotics that are used excessively and disposed of improperly are categorized as emerging pollutants. The determination of micropollutants in water with an accurate and precise method is always a big challenge. Hence, a simple, rapid, sensitive, economical and almost eco-friendly method is proposed for the quantitative determination of 19 antibiotics. The proposed method, ultrasound-assisted emulsification microextraction and solidified floating organic droplet coupled with liquid chromatography and triple quadrupole mass spectrometry, has only a 3 min chromatographic run time for the determination of the 19 antibiotics...
May 5, 2017: Journal of Separation Science
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