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Journal of Separation Science

Ting Sun, Hefeng Sun, Feng Zhao
In this work, reduced graphene oxide coated with ZnO nanocomposites was used as an efficient sorbent of dispersive solid-phase extraction and successfully applied to extraction of organochlorine pesticides from apple juice followed by gas chromatography with mass spectrometry. Several experimental parameters affecting the extraction efficiencies, including the amount of adsorbent, extraction time, and the pH of the sample solution, as well as the type and volume of eluent solvent, were investigated and optimized...
July 19, 2017: Journal of Separation Science
Murali Mohan Reddy Devalapalli, Hanumanth Srikanth Cheruvu, Thejaswi Yertha, Vijaya Bhaskar Veeravalli, Sunitha Sampathi, Savithri Shivakumar
A simple, specific, sensitive validated method was developed using liquid chromatography with tandem mass spectrometry with electrospray ionization of human plasma for the simultaneous estimation of drugs (simvastatin, ramipril, atenolol, hydrochlorothiazide and aspirin) of Polycap(TM) capsule used in cardiovascular therapy. The interaction of these actives including internal standards between the stationary and mobile phase were investigated using Hansen solubility parameters. Chromatographic separation was performed on Phenomenex Synergi Polar-RP (30 × 2 mm, 4 μm) column with a gradient mobile phase composition of acetonitrile and 5 mM ammonium formate for positive mode and 0...
July 19, 2017: Journal of Separation Science
Manal Eid, Yasser El-Shabrawy, Rania El-Shaheny
We present an environmentally friendly method for the analysis of three angiotensin-converting enzyme inhibitors and hydrochlorothiazide simultaneously using a green micellar eluent for the first time. The chromatographic separation of enalapril maleate, lisinopril dihydrate, benazepril hydrochloride, and hydrochlorothiazide was implemented on an octadecyl silica column with a solution containing sodium dodecyl sulfate (0.12 M), 1-propyl alcohol (10% v/v), triethylamine (0.3% v/v) and H3 PO4 (0.02 M) at pH 3...
July 19, 2017: Journal of Separation Science
Lei Zhou, Qiang Zhang, Wen Qi, Shuai Yan, Jialin Qu, Toshiaki Makino, Dan Yuan
Xiao-Qing-Long-Tang is a traditional Chinese formula used for the treatment of cold syndrome, bronchitis, and nasal allergies for thousands of years. However, the in vivo integrated metabolism of its multiple components and the active chemical constituents of Xiao-Qing-Long-Tang remain unknown. In this study, a method using ultra high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was established for the detection and identification of the metabolites in human and rat urine after oral administration of Xiao-Qing-Long-Tang...
July 18, 2017: Journal of Separation Science
Helena Prosen, Núria Fontanals, Francesc Borrull, Rosa Maria Marcé
A method based on liquid chromatography with electrospray ionization high-resolution mass spectrometry (Exactive Orbitrap) combined with solid-phase extraction using a strong cationic exchange mixed-mode sorbent has been developed for the determination of seven drugs of abuse, including two synthetic cathinones, as well as some of their metabolites in environmental water samples. The method provides low detection limits and a high confirmation power thanks to the diagnostic and two fragment ions monitored for each compound in high-resolution mass spectrometry, providing six identification points for each analyte...
July 18, 2017: Journal of Separation Science
Weidong Wang, Yanduo Tao, Lijin Jiao, Minxia Fan, Yun Shao, Qilan Wang, Lijuan Mei, Jun Dang
The separation of high-purity compounds from traditional Tibetan medicines plays an important role in investigating their bioactivity. Nevertheless, it is often quite difficult to isolate compounds with high purity because of the complexity of traditional Tibetan medicines. In this work, an offline two-dimensional reversed-phase preparative method was successfully developed for the separation of high-purity compounds from Oxytropis falcata. Based on the analysis results, an ODS C18 prep column was used for first-dimensional preparation, and 14...
July 18, 2017: Journal of Separation Science
Xu Ling, Li Zou, Zilin Chen
A polymeric column that contains a multiwalled carbon nanotubes-β-cyclodextrin composite was developed. The composite was wrapped into the poly(butyl methacrylate-ethylene dimethacrylate) monolith column (0.76 mm I.D. and 10 cm in length). The column was then applied for the online solid-phase microextraction of psoralen and isopsoralen from Fructus Psoraleae. Following microextraction, the coumarins were quantified by high-performance liquid chromatography with C18 separation column and UV detection. The effects of sample flow rate, sample volume and pH value were optimized...
July 17, 2017: Journal of Separation Science
Xinyu Liang, Juntao Wang, Juanjuan Wu, Qiuhua Wu, Chun Wang, Zhi Wang
A three-dimensional graphene was synthesized through a hydrothermal reaction of graphene oxide with phytic acid. The microstructure and morphology of the phytic acid induced three-dimensional graphene were investigated by nitrogen adsorption-desorption isotherms, scanning electron microscopy and transmission electron microscopy. With a large surface area and three-dimensional structure, the graphene was used as the solid-phase extraction adsorbent for the extraction of phthalate esters from bottled water and sports beverage samples before high-performance liquid chromatographic analysis...
July 17, 2017: Journal of Separation Science
Mohammadreza Taheri, Mohsen Bagheri, Roudabeh Sadat Moazeni-Pourasil, Alireza Ghassempour
Hydrophilic interaction liquid chromatography on bare silica presents some benefits for analysis and purification of ionizable basic alkaloids. This method was used to separate five major opium alkaloids: morphine, codeine, thebaine, papaverine, and noscapine. Central composite design based on response surface methodology was applied for experimental design, modeling, and optimization in a single-step gradient method. The main effects and their interactions (initial percentage of modifier, changing range of modifier in run time, pH of buffer, and its concentration) were investigated in 30 experiments...
July 17, 2017: Journal of Separation Science
Rahele Shamekhi, Homayon Ahmad Panahi, Haniyeh Sadat Alaei, Elham Moniri
In this study, a novel magnetic nanoadsorbent was synthesized by grafting β-cyclodextrin onto the modified surface of Fe3 O4 nanoparticles for the sorption and extraction of sertraline hydrochloride from human biological fluids. The extracted sertraline hydrochloride was measured by high-performance liquid chromatography. The grafted nanosorbent was confirmed by Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis and elemental analysis. The kinetic sorption of sertraline hydrochloride by magnetic nanosorbent was 1 h...
July 17, 2017: Journal of Separation Science
Yi Feng Lee, Simon Kluters, Mirjam Hillmann, Thomas von Hirschheydt, Christian Frech
The increasing demand for cost-efficient manufacturing of biopharmaceuticals has been the main driving force for the development of novel chromatography resins, which resulted in the development of multimodal or mixed-mode chromatographic resins. Most of them combine electrostatic and hydrophobic functionalities and are designed to deliver unique selectivity and increased binding capacities also at increased ionic strength. However, the mechanism of the protein-resin interaction in mixed-mode chromatography is still not fully understood...
July 17, 2017: Journal of Separation Science
Xuemei Li, Xiqian Li, Haijiao Zheng, Jiutong Ma, Guoxing Xu, Qiong Jia
Immobilized metal affinity chromatography has drawn great attention as a widespread separation and purification approach. In this work, ruthenium was firstly introduced into the preparation of immobilized metal affinity chromatography considering its affinity to N,O-donor ligands. A β-cyclodextrin-functionalized poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was designed and employed as the supporting material in immobilized metal affinity chromatography. Thiosemicarbazide was introduced into the synthesis process, which not only acted as a bridge between β-cyclodextrin and glycidyl methacrylate, but also chelated with ruthenium because of its mixed hard-soft donor characteristics...
July 14, 2017: Journal of Separation Science
Xiaoli Gu, Jiaojiao Huang, Lei Zhang, Yu Zhang, Chong-Zhi Wang, Chenghong Sun, Dandan Yao, Fei Li, Lina Chen, Chun-Su Yuan
In the scope of stroke treatment, new neuronal nitric oxide synthase-postsynaptic density protein-95 uncouplers from herbal medicines were discovered and captured. To do so, highly selective magnetic molecularly imprinted polymers with a core-shell structure were prepared as artificial antibodies. According to the results of computational simulations, we designed and synthesized various polymers with varying amounts and types of template, functional monomer, cross-linker and solvent. Characterization and performance tests revealed that the most appropriate artificial antibodies showed uniform spherical morphologies, large adsorption capacities, fast binding kinetics, high selectivity and quick separation...
July 13, 2017: Journal of Separation Science
Mengxia Lu, Xiaoping Wang, Zhisi Bu, Liqiong Lv, Shengqiang Tong
In this work, the anti-tumor constituent β-elemene was selectively separated from the volatile oil of the Curcumae Rhizoma by countercurrent chromatography with silver nitrate as selective reagent based on the formation of coordination complexes. A biphasic solvent system composed of n-hexane/methanol/water (2:1.5:0.5, v/v/v) was selected, in which 0.15 mol L(-1) of silver nitrate was added to the aqueous phase. The aqueous phase was used as the stationary phase for separation of β-elemene by countercurrent chromatography after it was partially purified from the volatile oil by silica gel column chromatography...
July 13, 2017: Journal of Separation Science
Sirwan Mohammadiazar, Nastaran Fallahpour, Ali Roostaie, Bahram Ebrahimi
In this study a novel technique is proposed for preparation of an efficient and unbreakable metal-wire-supported solid-phase microextraction fiber. A sol-gel film was deposited on electrophoretically deposited carbon nanotubes on a stainless-steel wire. The applicability of the fiber was evaluated through the extraction of some aromatic pollutants as model compounds from the headspace of aqueous samples in combination with gas chromatography and mass spectrometry. The parameters affecting the structure and extraction efficiency of the fiber (including the type of solvent, time and potential for electrophoretic deposition) and the parameters affecting the extraction efficiency (such as coating type, salt content, extraction temperature and time) were investigated...
July 10, 2017: Journal of Separation Science
Barbora Cervinkova, Lenka Kujovska Krcmova, Sava Klabackova, Dagmar Solichova, Petr Solich
A high-throughput miniaturized liquid-liquid extraction procedure followed by a simple ultra high performance liquid chromatography method coupled with fluorescence detection for bioanalytical analysis of all tocopherol isomers and retinol in human serum has been developed and validated. In extraction procedure, a synthetic internal standard tocol was used, which does not occur in the human body. The separation of structurally related vitamins was achieved using a new generation of pentafluorophenyl propyl core-shell stationary phase with elution using methanol and an aqueous solution of ammonium acetate...
July 8, 2017: Journal of Separation Science
Alexander Kurganov, Anastasiya Kanateva, Valeriya Shiryaeva, Tamara Popova, Alexander Korolev
Poly[oligo(ethylene glycol)diacrylate]s were investigated as potential candidates for application as stationary phases in capillary gas chromatography. Depending on the molar mass of the monomer, up to three different phase transitions were observed in calorimetric scans of the polymers. Two transitions have been identified as the glass transition and melting of crystallites while the nature of the third effect remains unknown. The new stationary phases demonstrate a good separating ability and selectivity in the viscous-elastic state i...
July 7, 2017: Journal of Separation Science
Lin Song, Zhen Zheng, Chen Liang, Xiujuan Chen, Runsheng Zhang, Zhanying Hong, Yifeng Chai
A rapid and sensitive gas chromatography with mass spectrometry method for the determination of venlafaxine in rat plasma has been developed and applied to a drug-drug interaction study of fluoxetine on pharmacokinetics of venlafaxine in rats. Rat plasma was spiked with 2% aqueous ammonia before subjected to preactivated C18 solid-phase extraction columns and eluted with methanol. No endogenous interferences were observed under optimal condition. The calibration curve was linear (R(2)  = 0.9994) in the range of 10-1000 ng/mL...
July 7, 2017: Journal of Separation Science
Baofei Yan, Weijie Xu, Shulan Su, Shaoqing Zhu, Zhenhua Zhu, Huiting Zeng, Ming Zhao, Dawei Qian, Jin-Ao Duan
Scutellaria baicalensis is a traditional Chinese herbal medicine containing multiple components, which has been extensively used in clinics to treat epidemic febrile disease and hyperactivity cough. To get a deeper understanding about Scutellaria baicalensis stem-leaf resources, we analyzed 15 chemical constituents in 35 batches of Scutellaria baicalensis stem-leaf from eight regions in China. A rapid, simple and sensitive method using ultra high performance liquid chromatography coupled with triple quadrupole electrospray tandem mass spectrometry has been developed for the first time to simultaneously determine 15 chemical constituents (including phenolic acids and flavonoids) in Scutellaria baicalensis stem-leaf...
July 7, 2017: Journal of Separation Science
Sunil Kumar, Awantika Singh, Vikas Bajpai, Bikarma Singh, Brijesh Kumar
Phyllanthus species are extensively used in traditional medicines for the treatment of hepatic diseases due to their bioactive hypophyllanthin and phyllanthin since ancient times. This work describes the development and validation of an ultra high performance liquid chromatography with tandem mass spectrometry method in polarity switching multiple reaction monitoring mode for the simultaneous detection and quantitation of 23 compounds using ultra performance liquid chromatography coupled with electrospray-hybrid triple quadrupole-linear ion trap mass spectrometer...
July 6, 2017: Journal of Separation Science
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