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Journal of Chromatography. A

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https://www.readbyqxmd.com/read/27923477/hydrophilic-interaction-chromatography-multiple-reaction-monitoring-mass-spectrometry-method-for-basic-building-block-analysis-of-low-molecular-weight-heparins-prepared-through-nitrous-acid-depolymerization
#1
Xiaojun Sun, Zhimou Guo, Mengqi Yu, Chao Lin, Anran Sheng, Zhiyu Wang, Robert J Linhardt, Lianli Chi
Low molecular weight heparins (LMWHs) are important anticoagulant drugs that are prepared through depolymerization of unfractionated heparin. Based on the types of processing reactions and the structures of the products, LMWHs can be divided into different classifications. Enoxaparin is prepared by benzyl esterification and alkaline depolymerization, while dalteparin and nadroparin are prepared through nitrous acid depolymerization followed by borohydride reduction. Compositional analysis of their basic building blocks is an effective way to provide structural information on heparin and LMWHs...
November 30, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27914606/erratum-to-simulation-of-elution-profiles-in-liquid-chromatography-i-gradient-elution-conditions-and-with-mismatched-injection-and-mobile-phases-solvents-j-chromatogr-a-1457-2016-41-49
#2
Lena N Jeong, Ray Sajulga, Steven G Forte, Dwight R Stoll, Sarah C Rutan
No abstract text is available yet for this article.
November 30, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27919519/investigation-of-the-acid-base-and-electromigration-properties-of-5-azacytosine-derivatives-using-capillary-electrophoresis-and-density-functional-theory-calculations
#3
Denisa Geffertová, Syed Tahir Ali, Veronika Šolínová, Marcela Krečmerová, Antonín Holý, Zdeněk Havlas, Václav Kašička
Capillary electrophoresis (CE) and quantum mechanical density functional theory (DFT) were applied to the investigation of the acid-base and electromigration properties of important compounds: newly synthesized derivatives of 5-azacytosine - analogs of efficient antiviral drug cidofovir. These compounds exhibit a strong antiviral activity and they are considered as potential new antiviral agents. For their characterization and application, it is necessary to know their acid-base properties, particularly the acidity constants (pKa) of their ionogenic groups (the basic N(3) atom of the triazine ring and the acidic phosphonic acid group in the alkyl chain)...
November 29, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27916391/liquid-chromatography-electrospray-ionization-mass-spectrometry-for-the-simultaneous-quantitation-of-collagen-and-elastin-crosslinks
#4
Rafea Naffa, Geoff Holmes, Meekyung Ahn, David Harding, Gillian Norris
We have developed a novel chromatographic analytical method for the simultaneous quantitation of collagen crosslinks. Seven non-derivatised crosslinks could be separated on a Cogent Diamond Hydride HPLC column using either isocratic or gradient conditions then detected by mass spectrometry. The total run time was less than 10min which is significantly shorter than that previously reported. This is the first method in which histidinohydroxylysinonorleucine (HHL) and histidinohydroxymero-desmosine (HHMD) were separated and identified by mass spectrometry without the need for pre- or post-column derivatization...
November 29, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27916390/chromatographic-behavior-of-selected-antibiotic-drugs-supported-by-quantitative-structure-retention-relationships
#5
Malgorzata Szultka-Mlynska, Boguslaw Buszewski
As antibiotic drugs have a wide variety of applications, there is a growing demand for their selective determination, a task for which chromatographic methods seem to be appropriate. With this end in view, chromatographic measurements were performed with the use of six different HPLC columns (ACE 5C18, IAM.PC.DD.2, octadecyl, phenyl, alkylamide and cholesteryl-alkylamide) to determine the logkw of selected antibiotic drugs (amoxicillin, cefatoxime, ciprofloxacin, fluconazole, gentamicin, clindamycin, linezolid and metronidazole)...
November 29, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27916389/system-maps-for-retention-of-small-neutral-compounds-on-a-biphenylsiloxane-bonded-silica-stationary-phase-in-reversed-phase-liquid-chromatography
#6
Sanka N Atapattu, Colin F Poole, Mike B Praseuth
The system constants of the solvation parameter model are used to prepare system maps for the retention of small neutral compounds on a biphenylsiloxane-bonded superficially porous silica stationary phase (Kinetex Biphenyl) for aqueous-organic solvent mobile phases containing 10-70% (v/v) methanol or acetonitrile. The retention properties of the biphenylsiloxane-bonded phase are shown to be complementary to an octadecylsiloxane-bonded silica (Kinetex C-18) and a pentafluorophenylpropylsiloxane-bonded silica stationary phases (Discovery HS F5)...
November 29, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27914609/determination-of-diamondoids-in-crude-oils-using-gas-purge-microsyringe-extraction-with-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#7
Wanfeng Zhang, Shukui Zhu, Liling Pang, Xuanbo Gao, Gang-Tian Zhu, Donghao Li
Based on a homemade device, gas purge microsyringe extraction (GP-MSE) of crude oil samples was developed for the first time. As a simple, fast, low-cost, sensitive and solvent-saving technique, GP-MSE provides some outstanding advantages over the widely used sample preparation methods for crude oils such as column chromatography (ASTM D2549). Several parameters affecting extraction efficiency were optimized, including extraction temperature, extraction time, extraction solvent, condensing temperature and purge gas flow rate...
November 27, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27914608/evaluation-of-size-exclusion-chromatography-columns-packed-with-sub-3%C3%AE-m-particles-for-the-analysis-of-biopharmaceutical-proteins
#8
Alexandre Goyon, Alain Beck, Olivier Colas, Koen Sandra, Davy Guillarme, Szabolcs Fekete
The aim of this study was to evaluate the practical possibilities and limitations of several recently introduced size exclusion chromatographic (SEC) columns of 150×4.6mm, sub-3μm (Agilent AdvanceBioSEC 2.7μm, Tosoh TSKgel UP-SW3000 2.0μm, Phenomenex Yarra SEC X-150 1.8μm and Waters Acquity BEH200 1.7μm) for the separation of biopharmaceutical proteins. For this purpose, some model proteins were tested, as well as several commercial therapeutic monoclonal antibodies (mAbs) and antibody-drug-conjugates (ADCs)...
November 27, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27912968/validation-of-a-thin-layer-chromatography-densitometry-method-for-the-characterization-of-invertase-activity
#9
Justine Ferey, David Da Silva, Sophie Bravo-Veyrat, Pierre Lafite, Richard Daniellou, Benoît Maunit
This paper presents a kinetic study of invertase, a specific fructofuranosidase cloned from the Leishmania major genome. The kinetic parameters of the β-d-fructofuranosidase from Leishmania major (BfrA) were determined using Thin-Layer Chromatography (TLC) and UV-densitometry (TLC@UV) specifically developed for the separation and detection of three carbohydrates namely sucrose, glucose and fructose. Separation was performed on TLC silica gel 60 F254 plates impregnated with sodium bisulphate and citrate and heated prior to development...
November 25, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27908498/hydrophilic-interaction-and-reversed-phase-mixed-mode-liquid-chromatography-coupled-to-high-resolution-tandem-mass-spectrometry-for-polar-lipids-analysis
#10
Sara Granafei, Pietro Azzone, Vito Alessandro Spinelli, Ilario Losito, Francesco Palmisano, Tommaso R I Cataldi
A hydrophilic interaction liquid chromatography (HILIC) fused-core column (150×2.1mm ID, 2.7μm particle size) and a short reversed-phase liquid chromatography (RPLC) column (20mm×2.1mm ID, 1.9μm) were serially coupled to perform mixed-mode chromatography (MMC) on complex mixtures of phospholipids (PL). Mobile phase composition and gradient elution program were, preliminarily, optimized using a mixture of phosphatidylcholines (PC), phosphatidylethanolamines (PE), their corresponding lyso-forms (LPC and LPE), and sphingomyelins (SM)...
November 25, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27908494/simultaneous-microextraction-of-inorganic-iodine-and-iodinated-amino-acids-by-miniaturized-matrix-solid-phase-dispersion-with-molecular-sieves-and-ionic-liquids
#11
Jun Cao, Li-Qing Peng, Jing-Jing Xu, Li-Jing Du, Qi-Dong Zhang
This study presents an effective method of using miniaturized matrix solid phase dispersion (MSPD) for the microextraction of inorganic iodine and iodinated amino acids from seaweed samples. Quantification of the target analytes was performed by ultrahigh performance liquid chromatography with UV detection. Molecular sieve (SBA-15) was chosen as the dispersing adsorbent with an ionic liquid (1-dodecyl-3-methylimidazolium bromide) as the elution solvent. The experimental conditions for the MSPD, such as the type of sorbent, ratio of sorbent to sample, type and concentration of the elution solvent, and grinding time were evaluated and optimized...
November 25, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27903405/separation-of-44-ti-from-proton-irradiated-scandium-by-using-solid-phase-extraction-chromatography-and-design-of-44-ti-44-sc-generator-system
#12
V Radchenko, C A L Meyer, J W Engle, C M Naranjo, G A Unc, T Mastren, M Brugh, E R Birnbaum, K D John, F M Nortier, M E Fassbender
Scandium-44g (half-life 3.97h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, (18)F, due to its favorable decay parameters. One source of (44g)Sc is the long-lived parent nuclide (44)Ti (half-life 60.0 a). A (44)Ti/(44g)Sc generator would have the ability to provide radionuclidically pure (44g)Sc on a daily basis. The production of (44)Ti via the (45)Sc(p,2n) reaction requires high proton beam currents and long irradiation times...
November 24, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27908499/a-strategy-to-modulate-the-electrophoretic-behavior-in-plastic-microchips-using-sodium-polystyrene-sulfonate
#13
Jinxiu Guo, Yu Chen, Lizhi Zhao, Ping Sun, Hongli Li, Lei Zhou, Xiayan Wang, Qiaosheng Pu
Plastic microchips have been broadly used as disposable microfluidic devices, but the poorly defined surface properties limit their application. Herein, we proved that an anionic polymer could be used as the background electrolyte (BGE) to provide a strong and stable cathodic electroosmotic flow (EOF) and modulate the electrophoretic behavior for efficient separation in relative thicker microchannels (∼75μm id). A cathodic EOF of ∼3.3×10(-4)cm(2)V(-1)s(-1) was maintained using sodium polystyrene sulfonate (PSSNa) with a molecular weight of 5×10(5) as the BGE, which ensured fluorescein isothiocyanate labeled biogenic amines (BAs) appeared ahead of other components in the electropherograms obtained with microchips of cyclic olefin copolymer...
November 23, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27908497/the-use-of-an-inkjet-injection-technique-in-immunoassays-by-quantitative-on-line-electrophoretically-mediated-microanalysis
#14
Weifei Zhang, Sifeng Mao, Jianmin Yang, Hulie Zeng, Hizuru Nakajima, Shungo Kato, Katsumi Uchiyama
The paper describes a new online quantitative electrophoretically mediated microanalysis (EMMA) for use in immunoassays based on the unique drop-by-drop introduction of a sample by means of an inkjet for capillary electrophoresis (CE). Plugs of a fluorescein-labeled antibody (Anti-humanIgG-DyL550) and human IgG were alternately injected into a capillary using the inkjet, followed by the merging of the plugs and the subsequent immune reaction. The antigen-antibody complex that was formed in the merged zone was then separated by CE...
November 23, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27899179/capillary-methacrylate-based-monoliths-by-grafting-from-to-%C3%AE-ray-polymerization-on-a-tentacle-type-reactive-surface-for-the-liquid-chromatographic-separations-of-small-molecules-and-intact-proteins
#15
Patrizia Simone, Giuseppe Pierri, Donatella Capitani, Alessia Ciogli, Giancarlo Angelini, Ornella Ursini, Gennaro Gentile, Alberto Cavazzini, Claudio Villani, Francesco Gasparrini
Capillary methacrylate-based monoliths were prepared for the high performance liquid chromatography (HPLC) separation of both small molecules and large biomolecules. An efficient grafting from/to synthetic approach was adopted introducing a network of activated sites in the inner wall surface using the new silanization agent (N-trimethoxysilylpropyl)-polyethylenimine. Copolymerization of lauryl methacrylate monomer and 1,6-hexanediol dimethacrylate cross-linker in the presence of porogenic solvents was obtained under continuous γ-ray exposure with high conversion yield...
November 23, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27894697/an-innovative-ultrasound-assisted-extraction-micro-scale-cell-combined-with-gas-chromatography-mass-spectrometry-in-negative-chemical-ionization-to-determine-persistent-organic-pollutants-in-air-particulate-matter
#16
E Beristain-Montiel, R Villalobos-Pietrini, G E Arias-Loaiza, S L Gómez-Arroyo, O Amador-Muñoz
New clean technologies are needed to determine concentration of organic pollutants without generating more pollution. A method to extract Persistent Organic Pollutants (POPs) from airborne particulate matter was developed using a novel technology recently patented called ultrasound assisted extraction micro-scale cell (UAE-MSC). This technology extracts, filters, collects the sample, and evaporates the solvent, on-line. No sample transfer is needed. The cell minimizes sample manipulation, solvent consumption, waste generation, time, and energy; fulfilling most of the analytical green chemistry protocol...
November 23, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27912967/qualitative-analysis-of-copaifera-oleoresin-using-comprehensive-two-dimensional-gas-chromatography-and-gas-chromatography-with-classical-and-cold-electron-ionisation-mass-spectrometry
#17
Yong Foo Wong, Thais M Uekane, Claudia M Rezende, Humberto R Bizzo, Philip J Marriott
Improved separation of both sesquiterpenes and diterpenic acids in Copaifera multijuga Hayne oleoresin, is demonstrated by using comprehensive two-dimensional gas chromatography (GC×GC) coupled to accurate mass time-of-flight mass spectrometry (accTOFMS). GC×GC separation employs polar phases (including ionic liquid phases) as the first dimension ((1)D) column, combined with a lower polarity (2)D phase. Elution temperatures (Te) of diterpenic acids (in methyl ester form, DAME) increased as the (1)D McReynolds' polarity value of the column phase decreased...
November 22, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27912966/structure-related-related-new-approach-in-the-gc-ms-analysis-of-cathinone-type-synthetic-drugs
#18
Borbála Molnár, Blanka Fodor, Antal Csámpai, Előd Hidvégi, Ibolya Molnár-Perl
A novel, structure-related derivatization principle has been developed in order to quantify cathinone-type synthetic drugs (CTSDs), focusing on the most common pentedrone (PENT), including also 4-fluoromethcathinone (4-FMC), methcathinone (MCTN), 4-methylethcathinone (4-MEC), 3,4-dimethylmethcathinone (3,4-DMMC), and 4-ethylmethcathinone (4-EMC). Firstly, oximated and, secondly, trimethylsilylated CTSD derivatives were characterized by mass fragmentation patterns using GC/MS that led to the development of a harmonized, quantitative, two-steps derivatization methodology...
November 22, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27894696/complex-analysis-of-concentrated-antibody-gold-nanoparticle-conjugates-mixtures-using-asymmetric-flow-field-flow-fractionation
#19
Irina V Safenkova, Elvira S Slutskaya, Vasily G Panferov, Anatoly V Zherdev, Boris B Dzantiev
Conjugates of gold nanoparticles (GNPs) with antibodies are powerful analytical tools. It is crucial to know the conjugates' state in both the concentrated and mixed solutions used in analytical systems. Herein, we have applied asymmetrical flow field-flow fractionation (AF4) to identify the conjugates' state. The influence of a conjugate's composition and concentration on aggregation was studied in a true analytical solution (a concentrated mixture with stabilizing components). GNPs with an average diameter of 15...
November 22, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27894695/the-performance-of-atmospheric-pressure-gas-chromatography-tandem-mass-spectrometry-compared-to-gas-chromatography-high-resolution-mass-spectrometry-for-the-analysis-of-polychlorinated-dioxins-and-pcbs-in-food-and-feed-samples
#20
Guillaume Ten Dam, Igor Cabreira Pussente, Georges Scholl, Gauthier Eppe, Alexander Schaechtele, Stefan van Leeuwen
Recently, gas chromatography tandem mass spectrometry (GC-MS/MS) has been added in European Union (EU) legislation as an alternative to magnetic sector high resolution mass spectrometry (HRMS) for the analysis of dioxins and dioxin like polychlorinated biphenyls (dl-PCB) in food and feed. In this study the performance of APGC-MS/MS compared to GC-HRMS is investigated and compared with EU legislation. The study includes the legislative parameters, relative intermediate precision standard deviation (SRw,rel), trueness, sensitivity, linear range and ion ratio tolerance...
November 22, 2016: Journal of Chromatography. A
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