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Journal of Chromatographic Science

Mir Mahdi Zahedi, Ahmad Rezaei
After complexation of Cr(III) and Cr(VI) species with diethyldithiocarbamate (0.2 mmol/L), effective parameters of emulsification-based dispersive liquid microextraction procedure was optimized for its preconcentration in artificial seawater. Triton X-305 as the emulsifying disperser and mixture of the chloroform and carbon tetrachloride as the extraction solvents show a better behavior at sample pH of 6.5. The method was applied for extraction and UV detection (λ = 254 nm) of chromium species of the Chabahar Bay seawater prior to high-performance liquid chromatography (conditions: C18, methanol: acetic acid solution 2% v (85:15), flow rate of 0...
October 13, 2016: Journal of Chromatographic Science
Xuan Zhou, Cen Chen, Xiaolan Ye, Fenyun Song, Guorong Fan, Fuhai Wu
In this paper, by coupling reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC), a two-dimensional liquid chromatography system was developed for separation and identification of the active ingredients in Gardenia jasminoides Ellis (GJE). By applying the semi-preparative C18 column as the first dimension and the core-shell column as the second dimension, a total of 896 peaks of GJE were separated. Among the 896 peaks, 16 active ingredients including geniposide, gardenoside, gardoside, etc...
October 13, 2016: Journal of Chromatographic Science
Juan Wang, Nan Wu, Yaling Yang
A vortex-assisted hollow fiber liquid-phase microextraction method using a mixed solvent as the extraction solvent followed by high performance liquid chromatography diode-array detection was developed for the extraction and determination of two carotenoids including lutein and β-carotene from egg yolk. The method is based on the microextraction of carotenoids from sample solution into extracting agent (20 μL), which is located in the lumen of hollow fiber followed by vortex-mixing. The mixed solvent (1-octanol+1-undecanol, 6:4, v:v) was employed as extracting agent for it has suitable viscosity and compatible with carotenoids via hollow fiber...
October 12, 2016: Journal of Chromatographic Science
A Veloso, J R Leiza
Cross-contamination from the polymeric material of the vial caps used in size exclusion chromatography (SEC) and high-performance liquid chromatography autosamplers in the low molar mass (LMM) range (<2000 Da) of polymer samples was demonstrated with the help of matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) analysis. It is shown that polyethylene (PE) caps, if exposed to either short or long periods in tetrahydrofuran solvent, might extract oligomers that contaminate the LMM end of the SEC chromatograms...
October 12, 2016: Journal of Chromatographic Science
Jie Xu, Rui Yan
This study aims to study the changes of metabolism of Ephedra sinica Stapf caused by processing. A sensitive and rapid high-performance liquid chromatographic tandem mass spectrometry (LC-MS-MS) method was developed for the quantitation of the major metabolite of ephedrine, 4-hydroxyephedrine, utilizing lidocaine as the internal standard in rat urine. Urine samples were precipitated with acetonitrile. Chromatographic separation was achieved on an Ultimate C18 analytical column. Detection was performed by a multiple reaction monitoring mode via an electrospray ionization source operating in the positive ionization mode...
October 12, 2016: Journal of Chromatographic Science
Minoo Sadri, Hossein Vatani
An ionic liquid-mediated multi-walled carbon nanotube (MWCNT)-polydimethylsiloxane (PDMS) sorbent was developed for headspace solid-phase microextraction (HS-SPME) of phenolic compounds from human urine samples. Sol-gel method was used to prepare this sorbent. For this purpose, MWCNTs were functionalized covalently and were attached chemically to the hydroxyl-terminated PDMS. Prepared fiber showed high thermal stability (over than 320°C) and good lifespan (>210 times). These good performances can be attributed to the performance of carbon nanotubes and sol-gel method...
October 12, 2016: Journal of Chromatographic Science
Natalija Nakov, Liljana Bogdanovska, Jelena Acevska, Jasmina Tonic-Ribarska, Rumenka Petkovska, Aneta Dimitrovska, Lilia Kasabova, Dobrin Svinarov
In this research, as a part of the development of fast and reliable HPLC-MS/MS method for quantification of ibuprofen (IBP) enantiomers in human plasma, the possibility of IBP acylglucoronide (IBP-Glu) back-conversion was assessed. This involved investigation of in source and in vitro back-conversion. The separation of IBP enantiomers, its metabolite and rac-IBP-d3 (internal standard), was achieved within 6 min using Chiracel OJ-RH chromatographic column (150 × 2.1 mm, 5 μm). The followed selected reaction monitoring transitions for IBP-Glu (m/z 381...
October 12, 2016: Journal of Chromatographic Science
Younis F Hamad Abiedalla, Karim Abdel-Hay, Jack DeRuiter, C Randall Clark
A combination of GC-MS, MS/MS and GC-IR techniques were used to characterize the ring substitution pattern, the alkyl side-chain and the cyclic tertiary amine portions of a series of six homologous and regioisomeric methylenedioxyphenyl-aminoketones related to the designer drug, 3,4-methylenedioxypyrovalerone (MDPV). Chromatographic retention increases with the hydrocarbon content of the alkyl side-chain and the 3,4-methylenedioxy substitution pattern shows higher retention than the corresponding 2,3-methylenedioxy isomer...
October 12, 2016: Journal of Chromatographic Science
Yayu Huo, Yang Gao, Jie Mi, Xinrui Wang, Huimin Jiang, Hailong Zhang
Rosa davurica Pall. has been used as a traditional Oroqen medicine to treat dyspepsia, gastroenterologia, menoxenia and other diseases. In this study, the chemical constituents research on the fruit pulp of R. davurica led to the isolation and identification of nine bioactive pentacyclic triterpenoids and five of them were isolated from the plant for the first time. Subsequently a simple and rapid high-performance liquid chromatography (HPLC) method was established for the simultaneous quantification of the nine triterpenoids...
October 12, 2016: Journal of Chromatographic Science
Yamin Ma, Haiyan Liu, Aile Wei, Junxiao Qin, Shiqi Zhang, Wen Zhang, Ligai Bai
Poly(N-isopropylacrylamide-co-hexanediol diacrylate-co-ethylene dimethacrylate) [poly(NIPAAm-co-HDDA-co-EDMA)] monolithic column was prepared via in situ polymerization reaction. In order to investigate the porous properties of the monoliths prepared, the morphology was characterized by the scanning electron microscopy; the chemical group of the monolithic column was confirmed by a Fourier transform infrared spectroscopy method. The surface area was 39.1 m(2)/g by the nitrogen adsorption-desorption experiment...
October 11, 2016: Journal of Chromatographic Science
Toshihiko Hanai, Masae Sekine, Hiroshi Homma
The retention mechanisms of nitrobenzofurazan (NBD)-amino acids in reversed-phase ion-pair liquid chromatography were quantitatively analyzed in silico The most contributed interaction for the retention is the Lewis acid-base interaction between an aromatic ring of NBD-amino acids and hydroxyl-group hydrogen of tetra-butyl-ammonium hydroxide coated on the hydrophobic phase. Solvent effects significantly improved the relation between the calculated molecular interaction (MI) energy values using a molecular mechanics program and log k values measured in chromatography...
September 27, 2016: Journal of Chromatographic Science
Norbert Rácz, Tibor Veress, Júlia Nagy, Balázs Bobály, Jenő Fekete
Cannabimimetic compounds have gained an increasing attention from the forensic community during the past few years. The present study was aimed to develop a liquid chromatographic separation method for the analysis of JWH-122 and its methyl isomers. In Hungary, JWH-122 is scheduled as a narcotic compound and its methyl isomers fall into the new psychoactive substance category, attracting significantly milder punishment than JWH-122 does. According to our best knowledge, gas chromatography or reversed phase liquid chromatography coupled with mass spectrometry could not be applied for separation and selective determination of methyl-naphthoyl indol isomers...
September 27, 2016: Journal of Chromatographic Science
Santosh K Gaykar, Ravindra B Shinde, Chetan M Bhalgat, Jayvant Harlikar, Manish Gangrade, Srinivas V Pullela
A sensitive and specific high-performance liquid chromatography (HPLC) method for the separation and quantification of 3-(S)-quinuclidinol in 3-(R)-quinuclidinol, precursor for active pharmaceutical ingredients (solifenacin, revatropate and talsaclidine), has been developed and validated by precolumn derivatization. Several chiral columns were tested in a normal phase system. Excellent enantioseparation with the resolution more than 11.4 was achieved on Chiralpak IC column using isocratic mobile phase consisting of n-hexane, ethanol, 2-propanol and diethylamine (80:8:12:0...
September 27, 2016: Journal of Chromatographic Science
Fawzia Ibrahim, Mohie K Sharaf El-Din, Asmaa Kamal El-Deen, Kuniyoshi Shimizu
An eco-friendly sensitive, rapid and less hazardous micellar liquid chromatographic method was developed and validated for the simultaneous analysis of ethamsylate (ETM) and mefenamic acid (MFA) in the presence of hydroquinone (HQ) and 2,3-dimethylaniline (DMA) the main impurities of ETM and MFA, respectively. Good chromatographic separation was attained using Eclipse XDB-C8 column (150 mm × 4.6 mm, 5 μm particle size) adopting UV detection at 300 nm with micellar mobile phase consisting of 0.12 M sodium dodecyl sulfate, 0...
September 27, 2016: Journal of Chromatographic Science
Mahmoud M Elkhoudary, Randa A Abdel Salam, Ghada M Hadad
A new simple, sensitive, rapid and accurate gradient reversed-phase high-performance liquid chromatography with photodiode array detector (RP-HPLC-DAD) was developed and validated for simultaneous analysis of Metronidazole (MNZ), Spiramycin (SPY), Diloxanidefuroate (DIX) and Cliquinol (CLQ) using statistical experimental design. Initially, a resolution V fractional factorial design was used in order to screen five independent factors: the column temperature (°C), pH, phosphate buffer concentration (mM), flow rate (ml/min) and the initial fraction of mobile phase B (%)...
September 12, 2016: Journal of Chromatographic Science
Ping Chen, Siping Wei, Li Wang, Bin Tang, Shu Wang, Qin Wang, Xi Du
A rapid and sensitive high performance liquid chromatography method was developed and validated for the determination of enantiomeric purity of 1-styrene-3-hexyl propynol. Baseline separation with resolution greater than 2.0 was achieved within 17 min on a CHIRALCEL OD-H (25 cm × 0.46 cm; particle size 5 μm) column using n-hexane:isopropanol (95:5 v/v) as mobile phase at a flow rate of 1 mL·min(-1) and 25°C as column temperature. The analytes were detected by UV absorbance at 210 nm. The effects of column, composition of mobile phase, temperature and flow rate on the chromatography were investigated...
September 12, 2016: Journal of Chromatographic Science
M E Fathy, S Abo El Abass Mohamed, H Elmansi, F Belal
A simple and selective reversed-phase high-performance liquid chromatography method was developed for the estimation of cromolyn sodium (CRM) with either oxymetazoline hydrochloride (OMZ) or xylometazoline hydrochloride (XMZ) in their binary mixtures. The method is based on the simultaneous separation of each drug in a reversed-phase Waters symmetry(®) C18 column (250 mm × 4.6 mm intradermally, 5-µm particle size) at 25°C. Elution was performed with a mobile phase consisting of methanol : 0.1 M phosphate buffer (60:40, v/v, pH 4...
September 12, 2016: Journal of Chromatographic Science
Yu Zhang, Yajie Ma, Hong Yu, Yongqiang Liu
A rapid analytical method of ion exchange chromatography with indirect ultraviolet detection was developed to determine morpholinium ionic liquid (IL) cations, i.e. N-methyl-N-ethyl morpholinium cation ([MEMo](+)) and N-methyl-N-propyl morpholinium cation ([MPMo](+)). Chromatographic separation of morpholinium cations was performed on a sulfonic acid base cation exchange column using imidazolium ionic liquid-organic solvent as mobile phase. The effects of chromatographic columns, ultraviolet absorption reagents, imidazolium ILs, detection wavelength, organic solvents, pH values of the mobile phase and column temperature on the retention of morpholinium cations were investigated...
September 12, 2016: Journal of Chromatographic Science
Sudarat Jan-E, Yanawath Santaladchaiyakit, Rodjana Burakham
An ultrasound-assisted surfactant-enhanced emulsification micro-extraction (UASEME) procedure has been developed for pre-concentration of benzoic acid (BA) and paraben preservatives, including methylparaben, ethylparaben, propylparaben and butylparaben, prior to high-performance liquid chromatography-ultraviolet (HPLC-UV) analysis. Separations were performed on a Lichrospher RP-18 endcapped 5 µm, using an isocratic mobile phase of 40% acetonitile, at a flow rate of 1 mL min(-1) The selected UASEME conditions comprised the use of 10 mL sample extract, 125 µL 1-octanol as extraction solvent and 0...
September 12, 2016: Journal of Chromatographic Science
Tadiboyina Sirisha, Bannimath Gurupadayya, Bharath Kumar Inturi, Madhusudhan Purohit
Hydroxyzine is the first generation H1 receptor antagonist drug that is now marketed as a racemic mixture. The paper describes a validated enantioselective liquid chromatography method for the resolution of hydroxyzine enantiomers and cyclizine (internal standard) from 200 µL of rabbit plasma by liquid-liquid extraction technique using n-hexane and isopropanol. Hydroxyzine enantiomers were resolved at 10.2 and 11.1 min with good baseline resolution (Rs = 1.9) on a Lux amylose-2 chiral column (250 mm × 4...
September 12, 2016: Journal of Chromatographic Science
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