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Journal of Separation Science

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https://www.readbyqxmd.com/read/30028075/quantification-of-eight-active-ingredients-in-crude-and-processed-radix-polygoni-multiflori-applying-miniaturized-matrix-solid-phase-dispersion-microextraction-followed-by-uhplc
#1
Kun-Ze Du, Ying Chen, Jin Li, Ge Tang, Fei Tian, Jun He, Yan-Xu Chang
A rapid, efficient and green sample preparation method has been developed to extract eight active ingredients (gallic acid, catechins, epicatechin, polydatin, 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside, resveratrol, emodin and physcion) in Radix polygoni multiflori by miniaturized matrix solid-phase dispersion microextraction. Simple and sensitive ultra high performance liquid chromatography combined with ultraviolet detection has been applied to analyze the multiple compounds. The best results were obtained by adding 25 mg sample into 25 mg adsorbent and grinding for 2 min with disorganized silica as adsorbent and 1 mL 150 mM 1-dodecyl-3-methylimidazolium bromide as a green eluting solvent...
July 20, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30027558/surface-molecularly-imprinted-polymers-prepared-by-two-step-precipitation-polymerization-for-the-selective-extraction-of-oleanolic-acid-from-grape-pomace-extract
#2
Chunxia Lu, Zonggui Tang, Xiaomei Ma, Changbin Liu
Surface molecularly imprinted polymers were successfully prepared by a novel two-step precipitation polymerization method. The first-step allowed the formation of 4-vinylpyridine divinylbenzene and trimethylolpropane trimethacrylate copolymeric microspheres. In the second-step precipitation polymerization, microspheres were modified with a molecularly imprinting layer of oleanolic acid as template, methacrylic acid as functional monomer, and divinylbenzene/ethylene glycol dimethacrylate as cross-linker. The obtained polymers had an average diameter of 4...
July 20, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30022588/dispersive-liquid-liquid-microextraction-with-in-situ-derivatization-coupled-with-gc-ms-for-the-determination-of-4-methylimidazole-in-red-ginseng-products-containing-caramel-colors
#3
Jangho Lee, Yunyeol Lee, Tae Gyu Nam, Hae Won Jang
A rapid analytical method for the determination of 4-methylimidazole from red ginseng products containing caramel colors was developed by using dispersive liquid-liquid microextraction with in situ derivatization followed by gas chromatography with mass spectrometry. Chloroform and acetonitrile were selected as the extraction and dispersive solvents, respectively, and based on the extraction efficiency, their optimum volumes were 200 and 100 μL, respectively. The optimum volumes of the derivatizing agent (isobutyl chloroformate) and catalyst (pyridine), pH, and concentration of NaCl in the sample solution were determined to be 25 μL, 100 μL, pH 7...
July 19, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30019392/synthesis-and-characterization-of-a-poly-p-phenylenediamine-based-electrospun-nanofiber-for-the-micro-solid-phase-extraction-of-organophosphorus-pesticides-from-drinking-water-and-lemon-and-orange-juice-samples
#4
Zahra Mehrani, Homeira Ebrahimzadeh, Ali Akbar Asgharinezhad
A new micro-solid-phase extraction sorbent was synthesized by electrospinning poly(p-phenylenediamine)/poly(vinyl alcohol) in the presence of cetyltrimethylammonium bromide. The modified nanofiber was prepared by removing the majority of the poly(vinyl alcohol) from the nanofiber blend by exposing it to the hot water. Scanning electron microscopy and surface analysis were performed to study the homogeneity and porosity of the electrospun nanofiber. In addition, Fourier transform infrared spectroscopy was applied for more characterization...
July 18, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30016573/simultaneous-hplc-with-diode-array-detection-and-hplc-with-time-of-flight-mass-spectrometric-confirmation-of-the-ten-bioactive-compounds-in-semen-sojae-preparatum
#5
Feng Qiu, Linyi Shi, Siqi Wang, Sha Wu, Manyuan Wang
Semen Sojae Preparatum is one of the most widely used traditional Chinese medicines. A reliable and accurate high-performance liquid chromatography with diode array detection method has been developed and validated for the quantitative determination of the ten bioactive compounds contained in Semen Sojae Preparatum. The samples were first extracted by pressurized liquid extraction using 80% ethanol at 100°C for 15 min and three static extraction cycles. Chromatographic separation was conducted on a C18 column using a mobile phase consisting of water and acetonitrile under gradient elution, and the detection wavelength was set at 210 nm...
July 17, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30015411/determination-of-the-softening-point-of-rosin-by-a-simple-and-automated-headspace-gas-chromatographic-technique
#6
Yi Dai, Zhen-Hua Yu, Jian-Bo Zhan, Bao-Shan Yue, Jiao Xie, Hao Wang, Xin-Sheng Chai
We report a simple and automated headspace gas chromatographic technique for the determination of the softening point of rosin. A lumpy solid of rosin is added into a headspace vial, then an automated step-wise temperature ramping and headspace sampling was performed at each temperature stage and gas chromatography measurement. By plotting the gas chromatography signal for an impurity in rosin vs. the temperature, a transition point (corresponding to the rosin softening point) was determined. The results show that the present method has a good precision (less than 0...
July 17, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30014601/simultaneous-determination-of-total-homocysteine-cysteine-glutathione-and-n-acetylcysteine-in-brain-homogenates-by-hplc
#7
Adrianna Kamińska, Patrycja Olejarz, Kamila Borowczyk, Rafał Głowacki, Grażyna Chwatko
We have developed a simple, fast, accurate and cheap method for simultaneous determination of total cysteine, homocysteine, glutathione and N-acetylcysteine in brain homogenates based on the reduction of disulfide bonds tris(2-carboxyethyl) phosphine, pre-column derivatization of free thiol groups with 2-chloro-1-methylquinolinium tetrafluoroborate followed by ion-pair reversed-phase high-performance liquid chromatography separation with ultraviolet detection. The separation of thiol derivatives was achieved in 10 min...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30011133/development-of-an-analytical-strategy-to-identify-and-classify-the-global-chemical-constituents-of-ziziphi-spinosae-semen-by-using-uhplc-with-quadrupole-time-of-flight-mass-spectrometry-combined-with-multiple-data-processing-approaches
#8
Xiaochai Zhu, Xiao Liu, Ke Pei, Yu Duan, Hui Zhu, Jia Ma, Yinghui Xu, Zejun Wu, Qigang Zhou, Baochang Cai
According to traditional Chinese medical theory, Ziziphi Spinosae Semen needs to be stir-fried before clinical application for its sedative-hypnotic effect enhancement. A rapid and comprehensive analysis strategy of ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and multiple data analysis platforms was developed for the efficient and sensitive identification of components in crude and parched Ziziphi Spinosae Semen to explore the composition changes that happen during the stir-frying process...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30011121/magnetic-solid-phase-extraction-of-pyrethroid-pesticides-in-environmental-water-samples-with-cofe-2-o-4-embedded-porous-graphitic-carbon-nanocomposites
#9
Kaixuan Ma, Meixing Zhang, Shengchao Miao, Xinyue Gu, Nan Li, Shihai Cui, Jing Yang
Magnetic CoFe2 O4 -embedded porous graphitic carbon nanocomposites were prepared through a facile solid-phase thermal reaction with NaCl as a template. The material was applied in the magnetic solid-phase extraction process coupled with high-performance liquid chromatography with a diode array detector to detect the trace fenpropathrin, cyhalothrin, S-fenvalerate and bifenthrin in different water samples. The synthesis conditions of nanomaterial including glucose concentration and calcination time on extraction performance for pyrethroid pesticides have been investigated...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30010247/magnetic-chitosan-functionalized-with-%C3%AE-cyclodextrin-as-ultrasound-assisted-extraction-adsorbents-for-the-removal-of-methyl-orange-in-wastewater-coupled-with-hplc
#10
Yunliang Dai, Kyung Ho Row
Three types of choline chloride based deep eutectic solvents were prepared and used to modify magnetic chitosan. The adsorption capacity of the three deep-eutectic-solvent-modified magnetic chitosan/carboxymethyl-β-cyclodextrin for removing methyl orange from wastewater was examined. The different deep eutectic solvents were used to strengthen the adsorption capacity of magnetic chitosan. Deep-eutectic-solvent-modified magnetic chitosan/carboxymethyl-β-cyclodextrin materials were characterized by Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller surface area measurements...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30010243/chromatographic-characterization-of-amphiphilic-di-and-tri-block-copolymers-of-poly-ethylene-oxide-and-poly-%C3%AE%C2%B5-caprolactone
#11
Muhammad Irfan, Adnan Murad Bhayo, Syed Ghulam Musharraf, Muhammad Imran Malik
Amphiphilic di- and tri-block copolymers based on poly(ethylene oxide) as a hydrophilic segment and poly(ε-caprolactone) as a hydrophobic part are synthesized by the ring-opening polymerization of ε-caprolactone while using poly(ethylene glycol)s and methoxy poly(ethylene glycol)s of varying molar masses as macro-initiators. The synthesized block copolymers are characterized with respect to their total relative molar mass and its distribution by size exclusion chromatography. Liquid chromatography at critical conditions of both blocks is established for analysis of individual block lengths and tracking presence of unwanted homopolymers of both types in the block copolymer samples...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30010238/miniaturised-capillary-ion-chromatograph-with-uv-light-emitting-diode-based-indirect-absorbance-detection-for-anion-analysis-in-potable-and-environmental-waters
#12
Eoin Murray, Yan Li, Sinead A Currivan, Breda Moore, Aoife Morrin, Dermot Diamond, Mirek Macka, Brett Paull
A miniaturised, flexible and low-cost capillary ion chromatography system has been developed for anion analysis in water. The ion chromatography has an open platform, modular design and allows for ease of modification. The assembled platform weighs ca. 0.6 kg and is 25 × 25 cm in size. Isocratic separation of common anions (F- , Cl- , NO2 - , Br- and NO3 - ) could be achieved in under 15 min using sodium benzoate eluent at a flow rate of 3 μL/min, a packed capillary column (0.150 × 150 mm) containing Waters IC-Pak 10 μm anion exchange resin, and light-emitting diode based indirect UV detection...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30009500/second-order-calibration-serves-as-a-remedial-measure-for-the-simultaneous-determination-of-andrographolide-and-dehydroandrographolide-in-andrographis-paniculata-and-its-preparations-by-hplc-without-complete-baseline-separation
#13
Xiao-Li Yin, Hui-Wen Gu, Qiao Wu, Tian-Qin Peng, Shan-Hui Zhang, Yang Liu
In this work, high-performance liquid chromatography with diode array detection was applied for the simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and its preparations. As a result of the incomplete baseline separation caused by complex backgrounds, classical univariate calibration method failed to determine accurate contents of the analytes. On this occasion, chemometric second-order calibration based on the well-known alternating trilinear decomposition algorithm was then explored to serve as an afterwards remedial tool to solve this problem...
July 16, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30009559/thermal-stability-of-poly-1-trimethylsilyl-1-propyne-and-the-gas-chromatographic-stationary-phase-based-on-it
#14
Valeriya Shiryaeva, Tamara Popova, Alexander Korolev, Anastasiia Kanateva, Alexander Kurganov
The thermal stability of poly[1-(trimethylsilyl)-1-propyne] is investigated by heating the capillary column with this polymer as the stationary phase with the subsequent separation of the test mixture of light hydrocarbons. It is shown that heating of the column up to 130°C does not cause a decrease in efficiency or in the retention time of solutes. A further increase of temperature results in both decrease of column efficiency and sorbate retention. However, a decrease of column retentivity goes in one way for all the tested hydrocarbons...
July 15, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30007006/hydrophobic-ionic-liquid-modified-thermo-responsive-molecularly-imprinted-monolith-for-the-selective-recognition-and-separation-of-tanshinones
#15
Weiyang Tang, Kyung Ho Row
A hydrophobic ionic liquid modified thermo-responsive molecularly imprinted monolith was synthesized using N-isopropylacrylamide as a thermo-responsive monomer and a long-chain hydrophobic ionic liquid as an auxiliary modification monomer. The ionic-liquid-modified thermo-responsive molecularly imprinted polymer was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. When the column temperature was 50°C, the synthesized monolithic column was successfully applied to the selective separation of homologue tanshinones within 7 min and eluted only by water (mobile phase) (theoretical plates more than 1...
July 14, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/30006947/chromatographic-method-for-the-simultaneous-quantification-of-dapsone-and-clofazimine-in-nanoformulations
#16
Sandia Machado, Sara R Fernandes, Luise L Chaves, Sofia A C Lima, Eduarda M P Silva, Luísa Barreiros, Salette Reis, Marcela Alves Segundo
The low bioavailability and non-specific distribution of dapsone and clofazimine, commonly applied in combination for the treatment of leprosy, can produce toxic effects. Nanotechnological approaches enhance the delivery of these drugs. Therefore, a high-performance liquid chromatography method was developed for the simultaneous determination of dapsone and clofazimine loaded in nanoformulations for quality control purposes. Chromatographic separation was achieved on a reversed-phase Kinetex core-shell C18 column, followed by spectrophotometric detection at 280 nm...
July 13, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/29999249/influence-of-acid-hydrolysis-saponification-and-sample-clean-up-on-the-measurement-of-phytosterols-in-dairy-cattle-feed-using-gc-ms-and-gc-with-flame-ionization-detection
#17
Samantha Duong, Norbert Strobel, Saman Buddhadasa, Katherine Stockham, Martin J Auldist, William J Wales, Peter J Moate, John D Orbell, Marlene Jane Cran
The fortification of processed foods including dairy products is increasingly commonplace with phytosterols among the many compounds used to improve the nutritional value of food products. It is also increasingly common practice for some dairy cattle feeds to be fortified for their potential to increase phytosterol levels in milk. In this study, a combined, streamlined protocol using acid hydrolysis, saponification and sample clean-up was developed to enable the rapid and reliable. The method was developed with focus on streamlining the overall technique to make it suitable for commercial laboratories, to reduce labor and consumable costs, while maintaining accuracy...
July 12, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/29998549/sensitive-high-throughput-and-eco-friendly-analysis-of-daidzein-and-its-valine-carbamate-prodrug-in-rat-plasma-by-supercritical-fluid-chromatography-with-tandem-mass-spectrometry
#18
Yingchao Li, Xingxing Zhang, Xiaochen Bai, Xiaoting Li, Qikun Jiang, Tianhong Zhang
A valine carbamate prodrug of daidzein was synthesized to improve its bioavailability because of the poor solubility and low permeability of daidzein. To evaluate the pharmacokinetic behavior of the prodrug, a sensitive and high-throughput method for the simultaneous determination of daidzein and its prodrug in rat plasma was developed and validated. The samples were extracted by ethyl acetate and then analyzed by a supercritical fluid chromatography with electrospray ionization tandem mass spectrometry method...
July 12, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/29995352/different-miniaturized-extraction-methodologies-followed-by-gc-ms-ms-analysis-for-the-determination-of-ultraviolet-filters-in-beach-sand
#19
Marlene Vila, Maria Llompart, Carmen Garcia-Jares, Thierry Dagnac
Four different miniaturized methodologies were developed and applied to the analysis of 11 UV filters in sand samples. These approaches were based on ultrasound and vortex extractions, on-column lixiviation, and ultrasound extraction followed by solid-phase microextraction. Gas chromatography with tandem mass spectrometry was used for quantitative analysis. The analytical performance provided by the four methods was evaluated in terms of linearity, accuracy, precision, and limits of quantification. Lixiviation was discarded since it provided the lowest recoveries and the highest limits of quantification...
July 11, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/29993191/poly-2-acryloyloxy-ethyl-trimethylammonium-chloride-co-ethylene-dimethacrylate-monolith-on-line-solid-phase-extraction-coupled-with-lc-ms-ms-for-the-fast-determination-of-salicylic-acid-in-foodstuffs
#20
Man-Man Wang, Na Li, Lian-Feng Ai, Li Li, Xue-Lei Chen, Ye-Qing Jia, Xue-Sheng Wang
We report the fabrication of an anion-exchange monolithic column in a stainless-steel chromatographic column (10 mm × 2.1 mm i.d.) using [2-(acryloyloxy) ethyl]trimethylammonium chloride as the monomer and ethylene dimethacrylate as the crosslinker. The prepared monolith was developed as the adsorbent for the on-line solid-phase extraction of salicylic acid in various animal-origin foodstuffs combined with liquid chromatography and tandem mass spectrometry. The monolith was characterized by using FTIR spectroscopy, scanning electron microscopy, nitrogen adsorption analysis and elemental analysis...
July 11, 2018: Journal of Separation Science
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