journal
MENU ▼
Read by QxMD icon Read
search

Chromatographia

journal
https://www.readbyqxmd.com/read/27885300/rebooting-the-franchise-the-2015-international-symposium-on-gpc-sec-and-related-techniques
#1
André M Striegel
No abstract text is available yet for this article.
August 2016: Chromatographia
https://www.readbyqxmd.com/read/27867207/purification-of-bioactive-lipopeptides-produced-by-bacillus-subtilis-strain-bia
#2
Muaaz Alajlani, Abid Shiekh, Shahida Hasnain, Adelheid Brantner
Bacillus subtilis strain BIA was used for the production of bioactive lipopeptides. Different extraction and purification methods were assayed as liquid-liquid extraction, and acid and ammonium sulfate precipitation followed by TLC, SPE, and gel filtration. Active fractions were further purified using RP-HPLC. The molecular mass of the purified product from HPLC was determined through Tris-Tricine SDS-PAGE and MALDI-TOF-MS. The results revealed that Bacillus subtilis strain BIA produced surfactin and iturin like compounds...
2016: Chromatographia
https://www.readbyqxmd.com/read/27738352/combining-chemometric-models-with-adsorption-isotherm-measurements-to-study-omeprazole-in-rp-lc
#3
Dennis Åsberg, Marek Leśko, Jörgen Samuelsson, Anders Karlsson, Krzysztof Kaczmarski, Torgny Fornstedt
The adsorption of the proton-pump inhibitor omeprazole was investigated using RP-LC with chemometric models combined with adsorption isotherm modelling to study the effect of pH and type of organic modifier (i.e., acetonitrile or methanol). The chemometric approach revealed that omeprazole was tailing with methanol and fronting with acetonitrile along with increased fronting at higher pH. The increased fronting with higher pH for acetonitrile was explored using a pH-dependent adsorption isotherm model that was determined using the inverse method and it agreed well with the experimental data...
2016: Chromatographia
https://www.readbyqxmd.com/read/27738351/liquid-crystals-as-stationary-phases-in-chromatography
#4
H Grajek, Z Witkiewicz, M Purchała, W Drzewiński
The most correct analysis of the compositions of diverse analytes mixtures is significant for analytical studies in different fields; however, many prevalent analytes cannot be identified employing traditional partition gas chromatographic methods. Thus, the increasing requirements on analytes of isomeric compounds and the problems encountered in their separation demand a study of more diverse analytical systems which are characterised by higher selectivity. Therefore, the selectivity and polarities of various liquid crystals (rod-like, banana-shape, biforked, oxygen, sulphur, nitrogen, and metal containing molecules, Schiff-base, and polymeric dendrimers) employed as liquid crystalline stationary phases (LCSPs) have been discussed from both points of views, namely, their analytical applications and thermodynamic characteristics of infinitely diluted probes with different acceptor-donor properties...
2016: Chromatographia
https://www.readbyqxmd.com/read/27616782/development-and-validation-of-a-uhplc-uv-method-for-the-in-process-control-of-bosentan-monohydrate-synthesis
#5
Marta Jatczak, Katarzyna Sidoryk, Magdalena Kossykowska, Wojciech Łuniewski, Joanna Zagrodzka, Elżbieta Lipiec-Abramska
Bosentan monohydrate (4-tert-butyl-N-[6-(2-hydroxyethoxy)-5-(2-methoxyphenoxy)-2-(pyrimidin-2-yl) pyrimidin-4-yl]benzene-1-sulfonamide monohydrate) is a dual endothelin receptor antagonist (ERA) applied in the treatment of pulmonary arterial hypertension. To achieve effective process control of the bosentan monohydrate synthesis, it was necessary to develop a selective and not highly time-consuming method for ultra-high performance liquid chromatography (UHPLC). The method is characterized by adequate sensitivity, reproducibility and selectivity for the determination of bosentan monohydrate and related compounds from all synthetic stages...
2016: Chromatographia
https://www.readbyqxmd.com/read/27616781/automated-mini-column-solid-phase-extraction-cleanup-for-high-throughput-analysis-of-chemical-contaminants-in-foods-by-low-pressure-gas-chromatography-tandem-mass-spectrometry
#6
Steven J Lehotay, Lijun Han, Yelena Sapozhnikova
This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography-tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. Cleanup efficiencies and breakthrough volumes using different mini-SPE sorbents were compared using avocado, salmon, pork loin, and kale as representative matrices. Optimum extract load volume was 300 µL for the 45 mg mini-cartridges containing 20/12/12/1 (w/w/w/w) anh...
2016: Chromatographia
https://www.readbyqxmd.com/read/27512157/comparison-of-the-multiple-reaction-monitoring-and-enhanced-product-ion-scan-modes-for-confirmation-of-stilbenes-in-bovine-urine-samples-using-lc-ms-ms-qtrap-%C3%A2-system
#7
Iwona Matraszek-Zuchowska, Barbara Wozniak, Andrzej Posyniak
In accordance with Commission Decision 2002/657/EC, confirmatory methods for the detection of prohibited substances should comply with specific requirements, including the criteria for confirmation. Two strategies: multiple reaction monitoring (MRM) and enhanced product ion (EPI) scanning functions were compared for confirming the anabolic compounds from synthetic stilbenes group in bovine urine samples. In the research, twenty samples fortified at the Recommended Concentration (RC) of 1 µg L(-1) with diethylstilbestrol, dienestrol and hexestrol were analyzed by liquid chromatography-tandem mass spectrometry on a QTRAP 5500 instrument...
2016: Chromatographia
https://www.readbyqxmd.com/read/27429473/determination-of-bendamustine-in-human-plasma-and-urine-by-lc-fl-methods-application-in-a-drug-monitoring
#8
Alina Plenis, Agnieszka Frolow, Natalia Rekowska, Ilona Olędzka, Piotr Kowalski, Ewa Bień, Małgorzata Anna Krawczyk, Elżbieta Adamkiewicz-Drożynska, Tomasz Bączek
Simple and sensitive liquid chromatography (LC) methods with fluorescence (FL) detection for the determination of bendamustine (BM) in human plasma and urine were developed and validated. The procedure of BM extraction from a plasma sample involved solid-phase extraction with a C18 SPE column, while liquid-liquid extraction with dichloromethane was applied for a urine sample. In both methods, cinoxacin was used as the internal standard. Chromatographic separations were performed on a Synergi Max-RP column, while FL detector was set at the excitation wavelength of 328 nm and the emission wavelength of 420 nm...
2016: Chromatographia
https://www.readbyqxmd.com/read/27069275/application-of-inverse-liquid-chromatography-for-surface-characterization-of-biomaterials
#9
Katarzyna Adamska, Karol Kadlec, Adam Voelkel
In the present study, a novel approach for surface characterization of ceramic biomaterials is proposed. Two ceramic biomaterials-hydroxyapatite and β-tricalcium phosphate-were examined by means of inverse liquid chromatography. The Abraham LFER model was applied for physicochemical characteristics of the surface. Different compounds, characterized by different polarity and different donor-acceptor properties of functional group, were used as test solutes. The chromatographic experiments were carried out with two compositions of the mobile phase: pure acetonitrile (MeCN) and the mixture of acetonitrile and water in 80:20 ratio (MeCN/H2O)...
2016: Chromatographia
https://www.readbyqxmd.com/read/25892741/applications-of-multiple-reaction-monitoring-to-clinical-glycomics
#10
L Renee Ruhaak, Carlito B Lebrilla
Multiple reaction monitoring or MRM is widely acknowledged for its accuracy of quantitation. The applications have mostly been in the analysis of small molecules and proteins, but its utility is expanding. Protein glycosylation was recently identified as a new paradigm in biomarker discovery for health and disease. A number of recent studies have now identified differential glycosylation patterns associated with health and disease states, including aging, pregnancy, rheumatoid arthritis and different types of cancer...
March 1, 2015: Chromatographia
https://www.readbyqxmd.com/read/26435545/choice-of-model-for-estimation-of-adsorption-isotherm-parameters-in-gradient-elution-preparative-liquid-chromatography
#11
Marek Leśko, Dennis Åsberg, Martin Enmark, Jörgen Samuelsson, Torgny Fornstedt, Krzysztof Kaczmarski
The inverse method is a numerical method for fast estimation of adsorption isotherm parameters directly from a few overloaded elution profiles and it was recently extended to adsorption isotherm acquisition in gradient elution conditions. However, the inverse method in gradient elution is cumbersome due to the complex adsorption isotherm models found in gradient elution. In this case, physicochemically correct adsorption models have very long calculation times. The aim of this study is to investigate the possibility of using a less complex adsorption isotherm model, with fewer adjustable parameters, but with preserved/acceptable predictive abilities...
2015: Chromatographia
https://www.readbyqxmd.com/read/25814696/high-throughput-analysis-and-automation-for-glycomics-studies
#12
Archana Shubhakar, Karli R Reiding, Richard A Gardner, Daniel I R Spencer, Daryl L Fernandes, Manfred Wuhrer
This review covers advances in analytical technologies for high-throughput (HTP) glycomics. Our focus is on structural studies of glycoprotein glycosylation to support biopharmaceutical realization and the discovery of glycan biomarkers for human disease. For biopharmaceuticals, there is increasing use of glycomics in Quality by Design studies to help optimize glycan profiles of drugs with a view to improving their clinical performance. Glycomics is also used in comparability studies to ensure consistency of glycosylation both throughout product development and between biosimilars and innovator drugs...
2015: Chromatographia
https://www.readbyqxmd.com/read/25750457/lipid-analysis-of-airway-epithelial-cells-for-studying-respiratory-diseases
#13
Nicole Zehethofer, Saskia Bermbach, Stefanie Hagner, Holger Garn, Julia Müller, Torsten Goldmann, Buko Lindner, Dominik Schwudke, Peter König
Airway epithelial cells play an important role in the pathogenesis of inflammatory lung diseases such as asthma, cystic fibrosis and COPD. Studies concerning the function of the lipid metabolism of the airway epithelium are so far based only on the detection of lipids by immunohistochemistry but quantitative analyses have not been performed. Although recent advances in mass spectrometry have allowed to identify a variety of lipid classes simultaneously in isolated tissue samples, up until now, these methods were not suitable to analyze lipids in the airway epithelium...
2015: Chromatographia
https://www.readbyqxmd.com/read/25750456/clinical-glycomics-employing-graphitized-carbon-liquid-chromatography-mass-spectrometry
#14
Kathrin Stavenhagen, Daniel Kolarich, Manfred Wuhrer
Glycoconjugates and free glycan are involved in a variety of biological processes such as cell-cell interaction and cell trafficking. Alterations in the complex glycosylation machinery have been correlated with various pathological processes including cancer progression and metastasis. Mass Spectrometry (MS) has evolved as one of the most powerful tools in glycomics and glycoproteomics and in combination with porous graphitized carbon-liquid chromatography (PGC-LC) it is a versatile and sensitive technique for the analysis of glycans and to some extent also glycopeptides...
2015: Chromatographia
https://www.readbyqxmd.com/read/25568463/thermodynamics-study-of-solvent-adsorption-on-octadecyl-modified-silica
#15
Szymon Bocian, Jan Soukup, Pavel Jandera, Bogusław Buszewski
Elution and solvation processes in liquid chromatography may be controlled by temperature changes. In the case of solvent adsorption, the temperature influences the amount of adsorbed solvent as well as the enthalpy and entropy of the solvation process. In this work, the thermodynamic parameters of organic solvents used as organic modifiers in the reversed-phase high-performance liquid chromatography elution process were determined. The changes of enthalpy and entropy in a series of chemically bonded stationary phases were measured to determine the effects of the temperature and surface coverage density of octadecyl ligands on the thermodynamic parameters of the solvation...
2015: Chromatographia
https://www.readbyqxmd.com/read/24855323/a-stability-indicating-hplc-method-for-the-determination-of-nitrosylcobalamin-no-cbl-a-novel-vitamin-b12-analog
#16
Michael J Dunphy, Annette M Sysel, Joseph A Lupica, Kristie Griffith, Taylor Sherrod, Joseph A Bauer
Nitrosylcobalamin (NO-Cbl), a novel vitamin B12 analog and anti-tumor agent, functions as a biologic 'Trojan horse', utilizing the vitamin B12 transcobalamin II transport protein and cell surface receptor to specifically target cancer cells. a stability-indicating HPLC method was developed for the detection of NO-Cbl during forced degradation studies. This method utilized an ascentis(®) RP-amide (150 mm × 4.6 mm, 5 μm) column at 35 °C with a mobile phase (1.0 mL min(-1)) combining a gradient of methanol and an acetate buffer at pH 6...
April 1, 2014: Chromatographia
https://www.readbyqxmd.com/read/25477555/development-of-an-analytical-method-for-the-rapid-quantitation-of-peptides-used-in-microbicide-formulations
#17
Yufei Chen, Sidi Yang, Emmanuel A Ho
Recently, a growing number of macromolecules such as peptides and proteins have been formulated into various microbicide formulations for the prevention of sexually transmitted infections. However, a fast and reliable high-throughput method for quantitating peptide/protein in polymer-based microbicide formulations is still lacking. As a result, we developed and validated a reversed-phase high-performance liquid chromatography method for the quantitation of gp120 fragment and LL-37 simultaneously in various microbicide gel formulations...
2014: Chromatographia
https://www.readbyqxmd.com/read/25477554/the-effects-of-stationary-phases-on-retention-and-selectivity-of-oligonucleotides-in-ip-rp-hplc
#18
Sylwia Studzińska, Lidia Pietrzak, Bogusław Buszewski
There is a growing demand for the separation and identification of short nucleic acid fragments, such as oligonucleotides. There were two main goals of the present investigation, namely, evaluation of the impact of stationary phase type and the influence of various ion-pair reagents on the retention behavior of oligonucleotides in ion-pair liquid chromatography. Three types of ion-pair reagents were studied: triethylammonium acetate, dimethylbuthylammonium acetate and mixtures of 1,1,1,3,3,3-hexafluoro-2-propanol and triethylamine...
2014: Chromatographia
https://www.readbyqxmd.com/read/25400289/the-development-and-validation-of-a-stability-indicating-uhplc-dad-method-for-determination-of-perindopril-l-arginine-in-bulk-substance-and-pharmaceutical-dosage-form
#19
Magdalena Paczkowska, Przemysław Zalewski, Piotr Garbacki, Alicja Talaczyńska, Anna Krause, Judyta Cielecka-Piontek
A stability-indicating ultra-high-performance liquid chromatography (UHPLC) method with a diode array detector was developed and validated for the determination of cis/trans isomers of perindopril l-arginine in bulk substance and pharmaceutical dosage form. The separation was achieved on a Poroshell 120 Hilic (4.6 × 150 mm, 2.7 µm) column using a mobile phase composed of acetonitrile-0.1 % formic acid (20:80 v/v) at a flow rate of 1 mL min(-1). The injection volume was 5.0 µL and the wavelength of detection was controlled at 230 nm...
2014: Chromatographia
https://www.readbyqxmd.com/read/25400288/assay-of-diastereoisomers-of-cefuroxime-axetil-in-amorphous-and-crystalline-forms-using-uhplc-dad
#20
Piotr Garbacki, Artur Teżyk, Przemysław Zalewski, Anna Jelińska, Magdalena Paczkowska, Alicja Talczyńska, Irena Oszczapowicz, Judyta Cielecka-Piontek
A sensitive UHPLC-DAD method was developed for determination of diastereoisomers of cefuroxime axetil in bulk substance in amorphous and crystalline forms as well as in pharmaceutical preparations. Chromatographic separation was achieved on Kinetex C-18 (100 mm × 2.1 mm, 1.7 µm) column with mobile phase consisting of 0.1 % formic acid:methanol (88:12, v/v), at the flow rate of 0.7 mL min(-1) and total run time of 3 min. The wavelength of the DAD detector was set at 278 nm. Inter-day precision (RSD) was less than 3 % and accuracy level ranged between 98...
2014: Chromatographia
journal
journal
22744
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"