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Journal of Chromatography. A

Heyong Cheng, Wenwen Zhang, Yuanchao Wang, Jinhua Liu
Metal speciation analysis of microsamples in the clinical, biological and forensic fields is important for elucidating the metals' toxicity, mobility and metabolic behaviors of metals. Such analysis may be achieved by nanoliter high-performance liquid chromatography (nanoHPLC) hyphenated with inductively coupled plasma mass spectrometry (ICP-MS). In this work, an in-column high-pressure nebulizer (ICHPN) was developed to enhance the sensitivity and the separation efficiency of the sheathless nanoHPLC-ICP-MS coupling...
September 17, 2018: Journal of Chromatography. A
Xiao-Li Yin, Hui-Wen Gu, Ali R Jalalvand, Ya-Juan Liu, Ying Chen, Tian-Qin Peng
The quantification of preservatives in cosmetics has attracted great attentions for their controversial and widespread use. HPLC is a prevailing method for preservatives determination among various analytical methods. However, it takes long time to fully separate these compounds because of the complexity of cosmetic matrices. In this study, a fast and green HPLC-DAD strategy assisted with second-order multivariate calibration methods based on alternating trilinear decomposition (ATLD) and multivariate curve resolution-alternating least squares (MCR-ALS) was developed for the simultaneous determination of eight selected preservatives in complex facial mask samples...
September 12, 2018: Journal of Chromatography. A
Yanxiao Jiang, Pinyi Ma, Xinpei Li, Huilan Piao, Dan Li, Ying Sun, Xinghua Wang, Daqian Song
In this work, a metal-organic framework material MIL-101(Cr) was prepared and used as the sorbent for a laboratory-made semi-automated microextraction in packed syringe (MEPS). Six triazine herbicides, including desmetryn, prometon, ametryn, prometryn, atraton, and dipropetryn, that are commonly found in corn samples, were extracted and determined by the MEPS method and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Key parameters affecting the extraction efficiencies, including type of extraction solvent, type and amount of sorbent, time of ultrasonic extraction and adsorption, and type, volume and flow rate of elution solvent, were investigated...
September 10, 2018: Journal of Chromatography. A
Mohammad Saraji, Hoda Ghambari
For the first time, the possibility of the use of liquid anion exchangers in dispersive liquid-liquid microextraction for the direct extraction of some inorganic anions (nitrite, nitrate, and iodide) was evaluated. In this technique, chloroform containing a liquid anion exchanger (trioctylamine) was used as extractant. The mixture of the extractant and disperser solvent (acetonitrile) was injected into the acidic sample solution. The protonated trioctylamine formed a water-insoluble salt with the inorganic anions (analytes)...
September 10, 2018: Journal of Chromatography. A
José Luis Ordóñez, Gema Pereira-Caro, Iziar Ludwig, José Manuel Muñoz-Redondo, María José Ruiz-Moreno, Alan Crozier, José Manuel Moreno-Rojas
The present study compared and validated two analytical methods, HPLC-HRMS, and GC-MS using MSTFA as derivatization agent, for the analysis of microbiota-derived phenolic acids and aromatic compounds accumulating in urine, collected over a 24 h period after the consumption of 500 mL of orange juice. In addition, purification procedures using SDB-L and HLB solid phase cartridges were compared when HPLC-HRMS technique was used. Both HPLC-HRMS and GC-MS methodologies were successfully validated in terms of specificity, sensitivity, limit of detection and quantification, recovery and matrix effects...
September 9, 2018: Journal of Chromatography. A
Sofia C Vardali, Victoria F Samanidou, Yannis P Kotzamanis
A UPLC-QTOF-MS method for the simultaneous determination of 20 veterinary drug residues and metabolites (tetracyclines, quinolones, sulfonamides and diaminopyrimidines) in edible muscle plus skin tissue of European sea bass (Dicentrarchus Labrax) was developed. For the identification of analytes a positive electrospray ionization quadropole time-of flight mass spectrometer operating in MSE mode (UPLC-QTOF-MSE ) was used. MSE mode provides high chromatographic resolution and accurate mass measurements in both MS and MS/MS modes simultaneously in a single run...
September 9, 2018: Journal of Chromatography. A
P-Shiqian Gao, Yutong Guo, Xinyue Li, Xuedong Wang, Junxia Wang, Feiyue Qian, Haidong Gu, Zhanen Zhang
A magnetic nano-adsorbent material was prepared by functionalizing carboxylic group onto the granule surface of magnetic graphene oxide nanoparticles (CMGO), using in-situ co-precipitating method. The surface morphology was characterized by SEM and TEM. The CMGO was selected as the adsorbent for the magnetic solid phase extraction (MSPE) of sulfonamides (SAs) from environmental water samples, and the eluted analytes were determined by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)...
September 8, 2018: Journal of Chromatography. A
Yang Zhang, Shanshan Wang, Jianguang Luo, Yaolan Lin, Xiao Xu, Chao Han, Lingyi Kong
Synephrine, a chiral adrenergic agonist, exists as R- (more active) and S-enantiomers (less active) that are difficult to separate because of their alkalinity and high polarity. Herein, we show that although this enantioseparation can hardly be achieved by high-performance liquid chromatography, acceptable preparative separation can be realized using high-speed counter-current chromatography (HSCCC) and pH-zone-refining counter-current chromatography (CCC) under optimal conditions. Specifically, 23.0 mg of S-synephrine and 25...
September 7, 2018: Journal of Chromatography. A
A Yanini, F A Esteve-Turrillas, M de la Guardia, S Armenta
A new drug trafficking trend has been observed in the last years by the introduction in the black market of new psychoactive substances (NPS) in order to difficult competent authority controls. In this study, ion mobility spectrometry (IMS) and high-resolution mass-spectrometry (HRMS) were proposed as vanguard and rearguard methodologies for the rapid identification of the last generation of NPS in seizures. The combined use of IMS and HRMS has been evaluated through the analysis of 24 NPS seized from 2016 to 2018 in Valencia (Spain) to demonstrate the utility of this approach...
September 7, 2018: Journal of Chromatography. A
Walter B Wilson, Lane C Sander
The research presented here describes the development of two analytical methods for use in the certification of a ginsenoside calibration solution Standard Reference Material (SRM) 3389 consisting of seven ginsenosides: Rg1, Re, Rf, Rb1, Rc, Rb2, and Rd. The new methods utilized the liquid chromatographic (LC) separation of ginsenoside mixtures with absorbance detection (UV) and mass spectrometry (MS). Ginsenosides Rb3, Rg2, Rg3, Rh1, and Rh2 were evaluated for use as internal standards for LC/MS measurements...
September 7, 2018: Journal of Chromatography. A
J A Navarro-Huerta, J R Torres-Lapasió, M C García-Alvarez-Coque
Peak capacity (PC ) is a key concept in chromatographic analysis, nowadays of great importance for characterising complex separations as a criterion to find the most promising conditions. A theoretical expression for PC estimation can be easily deduced in isocratic elution, provided that the column plate count is assumed constant for all analytes. In gradient elution, the complex dependence of peak width with the gradient program implies that an integral equation has to be solved, which is only possible in a limited number of situations...
September 7, 2018: Journal of Chromatography. A
Xiaohui Yan, Yingying Zhan, Dongdong Zhong, Yanshuo Li, Dapeng Wu
In order to achieve ultrafast solid phase micro-extraction (SPME) of trace organics in water samples, the robust polyimide/polyvinylpyrrolidone (PI/PVP) composite nanofiber was prepared by electrospinning. Unlike the nonwoven electrospun membrane bulk widely used for SPME, the hydrophilic PI/PVP nanofibers here can be easily dispersed into and recovered from water sample like a cloud, so nanofiber cloud SPME (NC-SPME) was proposed in this work. The extraction performance of the NC-SPME method was evaluated using phthalates and organochlorine pesticides as model analytes...
September 7, 2018: Journal of Chromatography. A
Franck Merlier, Nabila Imatoukene, Stéphane Octave, Jean-Marc Nicaud, Brigitte Thomasset
Fatty acid methyl esters (FAMEs), which are commonly used to characterize lipids, have several limitations to conclude on many structures. 3-Pyridylcarbinol esters (3-PCE) are used to characterize fatty acid structures [1], in particular, to identify ring and double bond positions on the carbon chain. Chromatographic separation of these esters is complex due to their polarity and high boiling points. In this study, we used a column with high resolutive power based on ionic liquids to increase the separation quality in gas chromatography (GC)...
September 7, 2018: Journal of Chromatography. A
Michael W C Kwan, Jason P Weisenseel, Nicholas Giel, Alexander Bosak, Christopher D Batich, Bradley J Willenberg
A rapid thermal desorption-gas chromatography-electron ionization-mass spectrometry (TD-GC-EI-MS) method for airborne transfluthrin detection is studied. Active air sampling of 9 L over 1 h at 23 °C through a Tenax®-loaded tube resulted in efficient capture of airborne transfluthrin. Subsequent thermal desorption was employed to achieve an LOD of 2.6 ppqv (parts per quadrillion by volume). A minimum primary desorption temperature of 300 °C is necessary for optimal recovery of sample from the Tenax® adsorbent...
September 5, 2018: Journal of Chromatography. A
Colin T Mant, Andrew Byars, Sean Ankarlo, Ziqing Jiang, Robert S Hodges
We are currently examining the potential of amphipathic cationic α-helical peptides as a new generation of peptide standards for both cation-exchange high-performance liquid chromatography and reversed-phase chromatography. Thus, amphipathic peptides are particularly suitable for high-performance liquid chromatography standards due to the preferred binding of the non-polar face to the hydrophobic stationary phase of reversed-phase packings or the preferred binding of the polar face to the charged/hydrophilic stationary phase of cation-exchange packings...
September 5, 2018: Journal of Chromatography. A
Elena Stekolshchikova, Polina Turova, Oleg Shpigun, Igor Rodin, Andrey Stavrianidi
The lack of standard substances is a bottleneck for quality control in traditional and alternative medicine. Development of the HPLC-UV approaches combined with single standard for quantitative analysis of multi-component system (QAMS) allowed determination of several plant biomarkers by implementation of the relative response factors (RRFs). Robustness and ruggedness of such methods are commonly demonstrated by performing the analysis in changing analytical conditions on the different HPLC equipment and columns...
September 5, 2018: Journal of Chromatography. A
Nyi Nyi Naing, Hian Kee Lee
Determination of α-dicarbonyl compounds, glyoxal (Gly) and methyl glyoxal (Mgly), in atmospheric fine particulate matter PM2.5 (particulate matter with an aerodynamic diameter of less than 2.5 μm) which play vital roles in generating secondary organic aerosols in the ambient air, was carried out by vortex-assisted micro-solid phase extraction (VA-μ-SPE)-liquid chromatography-diode array detection (LC-DAD), with on-sorbent derivatization by 2,4-dinitrophenylhydrazine (DNPH). This is the first time such an approach of combining on-sorbent derivatization and extraction in one step together with LC analysis has been applied to PM2...
September 5, 2018: Journal of Chromatography. A
E Lesellier, C West
Many different sorts of bonded phase chemistries may be used in high-performance liquid chromatography (HPLC) in the reversed-phase mode: C8, C18 (type A or B), polar-embedded C18, phenyl, pentafluorophenyl, or cyanopropyl. To assess their retention and selectivity properties, chromatographic tests exist. The data obtained from these tests may be presented in three ways. First, simple classification diagrams may be plotted, when only two or three parameters are studied. Secondly, chemometric treatments such as principal component analyses (PCA) or hierarchical cluster analyses (HCA) may be computed, when at least 4 parameters are studied...
September 3, 2018: Journal of Chromatography. A
Wei Huang, Panpan Wang, Ping Jiang, Xiangchao Dong, Shen Lin
A novel restricted access material (RAM) was prepared through combination of hydrophilic polymer poly(glycerol mono-methacrylate) and cross-linking bovine serum albumin (BSA) for direct biological analysis. In the material preparation, the poly(styrene-co-divinylbenzene) and poly(glycerol mono-methacrylate) were grafted on silica successively by atom transfer radical polymerization. Then the BSA was adsorbed on the material and cross-linked through an in-column process. The BSA recoveries of the resulted RAM were higher than 99...
September 3, 2018: Journal of Chromatography. A
Sandrine Huclier-Markai, Alicia Grivaud-Le Du, Estelle N'tsiba, Gilles Montavon, Marie Mougin-Degraef, Jacques Barbet
Alpha-particle-emitting radionuclides have been the subject of considerable investigation as cancer therapeutics, since they have the advantages of high potency and specificity. Among α-emitting radionuclides that are medically relevant and currently available, the lead-212/bismuth-212 radionuclide pair could constitute an in vivo generator. Considering its short half-life (T1/2  = 60.6 min), 212 Bi can only be delivered using labelled carrier molecules that would rapidly accumulate in the target tumor...
September 1, 2018: Journal of Chromatography. A
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