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Journal of Chromatography. A

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https://www.readbyqxmd.com/read/30017222/development-and-validation-of-a-method-for-direct-underivatized-analysis-of-free-amino-acids-in-rice-using-liquid-chromatography-tandem-mass-spectrometry
#1
G V V Liyanaarachchi, K R R Mahanama, H P P S Somasiri, P A N Punyasiri
Inspired by the apparent relationship of free amino acids (FAAs) which are present in minute quantities with the organoleptic characteristics of food, there is an increased demand for analytical methods sensitive in trace level detection. This study presents the validation results of a simple and rapid method developed for direct, underivatized analysis of FAAs in rice using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). The method demonstrated satisfactory selectivity for twenty FAAs with minimum matrix effect...
July 7, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30017221/direct-injection-analysis-of-polar-micropollutants-in-natural-drinking-water-sources-with-biphenyl-liquid-chromatography-coupled-to-high-resolution-time-of-flight-mass-spectrometry
#2
Vittorio Albergamo, Rick Helmus, Pim de Voogt
A method for the trace analysis of polar micropollutants (MPs) by direct injection of surface water and groundwater was validated with ultrahigh-performance liquid chromatography using a core-shell biphenyl stationary phase coupled to time-of-flight high-resolution mass spectrometry. The validation was successfully conducted with 33 polar MPs representative for several classes of emerging contaminants. Identification and quantification were achieved by semi-automated processing of full-scan and data-independent acquisition MS/MS spectra...
July 7, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30001901/direct-chromatographic-study-of-the-enantioselective-biodegradation-of-ibuprofen-and-ketoprofen-by-an-activated-sludge
#3
Laura Escuder-Gilabert, Yolanda Martín-Biosca, Mireia Perez-Baeza, Salvador Sagrado, María José Medina-Hernández
The quantification of the enantiomeric fraction (EF) during the biodegradation process is essential for environmental risk assessment. In this paper the enantioselective biodegradation of ibuprofen, IBU, and ketoprofen, KET, two of the drugs most consumed, was evaluated. Biodegradation experiments were performed in batch mode using a minimal salts medium inoculated with an activated sludge (collected from a Valencian Waste Water Treatment Plant) and supplemented with the racemate of each compound. The inoculum activity was verified using fluoxetine as reference compound...
July 7, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30001899/axial-heterogeneities-in-capillary-ultrahigh-pressure-liquid-chromatography-columns-chromatographic-and-bed-morphological-characterization
#4
Arved E Reising, Justin M Godinho, Janek Bernzen, James W Jorgenson, Ulrich Tallarek
We study axial heterogeneities in capillary ultrahigh pressure liquid chromatography (UHPLC) columns through kinetic performance and bed morphological analysis. Two columns are used in this work, a 75 μm i.d. × 100 cm column packed with 1.3 μm C18-silica particles and a 75 μm i.d. × 45 cm column packed with 1.9 μm C18-silica particles. The long column is chromatographically characterized and is afterwards sectioned into three segments, each analyzed individually. The column packed with the 1...
July 7, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30007792/multi-residue-enantiomeric-analysis-of-18-chiral-pesticides-in-water-soil-and-river-sediment-using-magnetic-solid-phase-extraction-based-on-amino-modified-multiwalled-carbon-nanotubes-and-chiral-liquid-chromatography-coupled-with-tandem-mass-spectrometry
#5
Pengfei Zhao, Zhaokun Wang, Kunjie Li, Xingjie Guo, Longshan Zhao
This manuscript describes, for the first time, the multi-residue analysis of 18 chiral pesticides at enantiomeric levels in both environmental liquid (river water, influent and effluent wastewater) and solid matrices (agricultural soil, forestal soil and river sediment) based on magnetic solid-phase extraction (MSPE) and chiral liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Magnetic amino modified multiwalled carbon nanotubes (m-MWCNTs-NH2 ) were prepared and firstly applied to adsorb pesticides from complex matrices...
July 6, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30005943/magnetic-beads-based-neuraminidase-enzyme-microreactor-as-a-drug-discovery-tool-for-screening-inhibitors-from-compound-libraries-and-fishing-ligands-from-natural-products
#6
Yu-Mei Zhao, Lv-Huan Wang, Si-Fan Luo, Qi-Qin Wang, Ruin Moaddel, Ting-Ting Zhang, Zheng-Jin Jiang
Neuraminidase (NA) is a glycoside hydrolase that has been proposed as a potential therapeutic target for influenza. Thus, the identification of compounds that modulate NA activity could be of great therapeutic importance. The aim of this study is to develop a drug discovery tool for the identification of novel modulators of NA from both compound libraries and natural plant extracts. NA was immobilized onto the surface of magnetic beads and the inherent catalytic activity of NA-functionalized magnetic beads was characterized...
July 6, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30005941/development-of-a-retention-time-interpolation-scale-rti-for-liquid-chromatography-coupled-to-mass-spectrometry-in-both-positive-and-negative-ionization-modes
#7
Alberto Celma, Lubertus Bijlsma, Francisco J López, Juan V Sancho
The accuracy and sensitivity of high resolution mass spectrometry (HRMS) enables the identification of candidate compounds with the use of mass spectrometric databases among other tools. However, retention time (RT) data in identification workflows has been sparingly used since it could be strongly affected by matrix or chromatographic performance. Retention Time Interpolation scaling (RTi) strategies can provide a more robust and valuable information than RT, gaining more confidence in the identification of candidate compounds in comparison to an analytical standard...
July 6, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30007793/lipidomic-alterations-in-lipoproteins-of-patients-with-mild-cognitive-impairment-and-alzheimer-s-disease-by-asymmetrical-flow-field-flow-fractionation-and-nanoflow-ultrahigh-performance-liquid-chromatography-tandem-mass-spectrometry
#8
San Ha Kim, Joon Seon Yang, Jong Cheol Lee, Ji-Yeon Lee, Jun-Young Lee, Eosu Kim, Myeong Hee Moon
Alzheimer's disease (AD) is an irreversible neurodegenerative disorder with the clinical symptom of the progressive loss of cognitive function and mild cognitive impairment (MCI) is a translational state between cognitive changes of normal aging and AD. Lipid metabolism and pathogenesis of Alzheimer's disease (AD) are closely linked. Despite obviously discrete lipidome constitutions across lipoproteins, lipidomic approaches of AD has been mostly conducted without considering lipoprotein-dependent alterations...
July 5, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30007791/quantification-of-run-order-effect-on-chromatography-mass-spectrometry-profiling-data
#9
Izabella Surowiec, Erik Johansson, Hans Stenlund, Solbritt Rantapää-Dahlqvist, Sven Bergström, Johan Normark, Johan Trygg
Chromatographic systems coupled with mass spectrometry detection are widely used in biological studies investigating how levels of biomolecules respond to different internal and external stimuli. Such changes are normally expected to be of low magnitude and therefore all experimental factors that can influence the analysis need to be understood and minimized. Run order effect is commonly observed and constitutes a major challenge in chromatography-mass spectrometry based profiling studies that needs to be addressed before the biological evaluation of measured data is made...
July 5, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30005942/chiral-capillary-zone-electrophoresis-in-enantioseparation-and-analysis-of-cinacalcet-impurities-use-of-quality-by-design-principles-in-method-development
#10
Benedetta Pasquini, Serena Orlandini, Mercedes Villar-Navarro, Claudia Caprini, Massimo Del Bubba, Michal Douša, Alessandro Giuffrida, Roberto Gotti, Sandra Furlanetto
A capillary electrophoresis method for the simultaneous determination of the enantiomeric purity and of impurities of the chiral calcimimetic drug cinacalcet hydrochloride has been developed following Quality by Design principles. The scouting phase was aimed to select the separation operative mode and to identify a suitable chiral selector. Among the tested cyclodextrins, (2-carboxyethyl)-β-cyclodextrin and (2-hydroxypropyl)-γ-cyclodextrin (HPγCyD) showed good chiral resolving capabilities. The selected separation system was solvent-modified capillary zone electrophoresis with the addition of HPγCyD and methanol...
July 5, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30001900/an-untargeted-lipidomic-strategy-combining-comprehensive-two-dimensional-liquid-chromatography-and-chemometric-analysis
#11
Meritxell Navarro-Reig, Joaquim Jaumot, Romà Tauler
Untargeted lipidomic samples are extremely complex and often exceed the limits of peak capacity achievable by one-dimensional liquid chromatography (LC). Comprehensive two-dimensional liquid chromatography (LC × LC) appears as a promising alternative to overcome this drawback. Unfortunately, this approach generates highly complex datasets which untargeted analysis is challenging. In this work, a global methodological strategy combining LC × LC-MS/MS with chemometric data analysis is proposed for untargeted lipidomic studies...
July 5, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30017223/qualitative-and-quantitative-comparison-of-cyclic-phosphatidic-acid-and-its-related-lipid-species-in-rat-serum-using-hydrophilic-interaction-liquid-chromatography-with-tandem-mass-spectrometry
#12
Keiko Fukasawa, Shingo Nakajima, Mari Gotoh, Seiya Tanaka, Hiromu Murofushi, Kimiko Murakami-Murofushi
Cyclic phosphatidic acid (cPA) is a simple lipid containing a fatty acid attached at the sn-1 position and a cyclic phosphate ring structure at the sn-2 and sn-3 positions of the glycerol backbone. The pharmacological effects of cPA have been demonstrated in several diseases such as cancer and neuropathic pain; however, the composition of the molecular species of cPA in relative to other lipid species in biological samples is still unclear. Recently, hydrophilic interaction liquid chromatography (HILIC) has demonstrated the ability to perform lipidomic analyses of biological samples...
July 4, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30005940/metabolomic-analysis-of-mammalian-cells-and-human-tissue-through-one-pot-two-stage-derivatizations-using-sheathless-capillary-electrophoresis-electrospray-ionization-mass-spectrometry
#13
Tianjiao Huang, Michael Armbruster, Richard Lee, Dawn S Hui, James L Edwards
Analysis of metabolites is often performed using separations coupled to mass spectrometry which is challenging due to their vast structural heterogeneity and variable charge states. Metabolites are often separated based on their class/functional group which in large part determine their acidity or basicity. This charge state dictates the ionization mode and efficiency of the molecule. To improve the sensitivity and expand the coverage of the mammalian metabolome, multifunctional derivatization with sheathless CE-ESI-MS was undertaken...
July 4, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/30007794/removal-of-bias-in-c-37-alkenone-based-sea-surface-temperature-measurements-by-high-performance-liquid-chromatography-fractionation
#14
Oscar Rama-Corredor, Aleix Cortina, Belen Martrat, Jordi F Lopez, Joan O Grimalt
Sea surface temperature determinations based on marine sedimentary C37 alkenone distributions have provided a wealth of data for paleoclimatic studies, including those performed at high resolution. The success of this approach results from several characteristics of alkenone compounds, e.g. their geochemical properties (such as unequivocal synthesis by certain widespread haptophyte algae, plus chemical stability/preservation of the original alkenone distributions during sedimentation), and their analytical properties (such as fast clean up procedures using alkaline hydrolysis of sediment extracts, followed by robust instrumental methods allowing large scale sample processing)...
July 3, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29983167/separation-of-highly-charged-compounds-using-competing-ions-with-hydrophilic-interaction-liquid-chromatography-application-to-assay-of-cellular-nucleotides
#15
Amitha K Hewavitharana, Vicrant Narayan, John A Duley
Separation of highly charged compounds has always been a challenge in chromatography. Ion-pair reversed phase chromatography has been the most successful approach to date. Although polar reversed phase and HILIC columns have been introduced, they have limitations with highly charged compounds. Competing ions have been used, in addition to ion-pair reagent, to achieve better resolution with reversed phase columns. Herein, we explored the use of competing ions with HILIC columns to demonstrate the effects on retention and separation of mono-, di-, and tri-nucleotides, introducing a new tool to improve resolution with HILIC columns...
July 3, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29983169/preparation-of-porous-zinc-ferrite-carbon-as-a-magnetic-assisted-dispersive-miniaturized-solid-phase-extraction-sorbent-and-its-application
#16
Shujun Xia, Zhixiong Cai, Jing Dong, Shuya Wang, Yiru Wang, Huaizhi Kang, Xi Chen
In this study, porous ZnFe2 O4 /carbon, derived from Zn-Fe zeolitic imidazolate framework (Zn-Fe-ZIF), was employed as a novel sorbent for magnetic-assisted dispersive miniaturized solid phase extraction (M-DμSPE). The Zn-Fe-ZIF derived magnetic porous ZnFe2 O4 /carbon was easily prepared using a one-pot solvothermal method, and its morphology, structure and magnetic characteristics were evaluated via scanning electron microscopy, powder X-ray diffraction, Raman spectroscopy and vibrating sample magnetometry...
July 2, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29983168/resolution-and-signal-to-noise-in-analysis-of-carbohydrate-isomers-by-graphitised-carbon-chromatography-with-charged-aerosol-detection
#17
Aleksander Lie, Lars Haastrup Pedersen
The effects of co-eluents and additives on separation and signal-to-noise ratio in analyses of monosaccharides by graphitised carbon chromatography (GCC) in combination with charged aerosol detection were studied. Design of experiments was used to model and predict the elution of two monosaccharide isomers, galactose and glucose and the corresponding amine at varying isocratic conditions, including concentration of water-soluble co-eluent, flow and temperature. The study confirmed the well-known order of eluent strength of the co-eluents investigated but showed that the eluent strength of MeOH was significantly lower than that of ACN, and at co-eluent concentrations ≥5% (v/v) IPA approached that of THF...
June 30, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29983166/separation-and-identification-of-phospholipids-by-hydrophilic-interaction-liquid-chromatography-coupled-to-tandem-high-resolution-mass-spectrometry-with-focus-on-isomeric-phosphatidylglycerol-and-bis-monoacylglycero-phosphate
#18
Christian Vosse, Carina Wienken, Cristina Cadenas, Heiko Hayen
Changes in lipid composition of cells or tissue are often linked to various diseases. Studies indicate alterations of bis(monoacylglycero)phosphate (BMP) species in diseases such as cancer. Therefore, an extended phospholipid profiling method based on hydrophilic interaction liquid chromatography (HILIC) coupled to high-resolution mass spectrometry (MS) and data-dependent MS/MS acquisition was developed to separate and unambiguously identify BMP species. Lipid species identification was based on retention time, accurate mass and specific MS/MS fragments...
June 30, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29961651/challenging-pharmaceutical-analyses-by-gas-chromatography-with-vacuum-ultraviolet-detection
#19
Jinjian Zheng, Chunli Huang, Simon Wang
Vacuum ultraviolet (VUV) detector for gas chromatography (GC) provides qualitative spectral information from 125 nm to 240 nm. In this article, this information was applied to facilitate the development of a GC method for challenging pharmaceutical applications. Seven organic solvents were screened for trace level water content using VUV detection at 168 nm, and the results were used to identify n-hexane as a suitable diluent for 4-ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO), a water reactive compound...
June 28, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29961650/quantification-of-inorganic-anions-and-organic-acids-in-apple-and-orange-juices-using-novel-covalently-bonded-hyperbranched-anion-exchanger-with-improved-selectivity
#20
A S Uzhel, A V Zatirakha, A D Smolenkov, O A Shpigun
Chromatographic analysis of orange and apple juices is provided using novel covalently-bonded poly(styrene-divinylbenzene)-based (PS-DVB) hyperbranched anion exchanger for suppressed ion chromatography (IC) with improved selectivity toward inorganic anions and organic acids. The obtained stationary phase provides baseline resolution of weakly retained organic acids such as glycolate, acetate, lactate, and formate, which are not separated to baseline with modern commercially available anion exchangers. The proposed method is validated with respect to linearity, recovery, limits of detection, and intra-day and inter-day precision...
June 28, 2018: Journal of Chromatography. A
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