Search results for "Electrophoresi"

A novel cholesterol-based detergent

2005

Design, synthesis and characterization of CHAPSTEROL, a novel cholesterol-based detergent developed for functional solubilization of cholesterol-dependent membrane proteins are described. To validate CHAPSTEROL, we employed the oxytocin receptor, a G protein-coupled receptor requiring cholesterol for its high-affinity binding state. Using the photoactivatable cholesterol analogue [3H]6,6-azocholestan-3beta-ol[3alphaH], we demonstrate that solubilization by CHAPSTEROL leads to an enrichment of cholesterol-binding proteins whereas the widely used bile acid derivative CHAPSO leads to a significant depletion of cholesterol-binding proteins. Similar to Triton X-100 and CHAPS, CHAPSTEROL maintain…

Partial vinylphenol reductase purification and characterization from Brettanomyces bruxellensis

2008

International audience; Brettanomyces is the major microbial cause for wine spoilage worldwide and causes significant economic losses. The reasons are the production of ethylphenols that lead to an unpleasant taint described as 'phenolic odour'. Despite its economic importance, Brettanomyces has remained poorly studied at the metabolic level. The origin of the ethylphenol results from the conversion of vinylphenols in ethylphenol by Brettanomyces hydroxycinnamate decarboxylase. However, no information is available on the vinylphenol reductase responsible for the conversion of vinylphenols in ethylphenols. In this study, a vinylphenol reductase was partially purified from Brettanomyces bruxe…

Determination of the Stability Constants of the Acetate Complexes of the Actinides Am(III), Th(IV), Np(V), and U(VI) Using Capillary Electrophoresis-…

2019

Capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) was used to determine the stability constants of the actinides Am(III), Th(IV), Np(V), and U(VI) at an ionic strength of I = 0.3 M. The obtained stability constants were extrapolated to zero ionic strength by means of the Davies equation. For both U(VI) and Am(III), three consecutive acetate complexes with log(β

A new ionic liquid dimethyldinonylammonium bromide as a flow modifier for the simultaneous determination of eight carboxylates by capillary electroph…

2005

Two new methods of capillary zone electrophoresis based on aqueous phosphate running buffers with UV spectrophotometric detection were developed and optimized for the determination of eight carboxylates as copper complexes. Metalcomplexes are negatively charged, so measurements were made as anion analyses with flow reversal in the capillary. Two flow modifiers were used: a common tetradecyltrimethylammonium bromide (TTAB) and a new ionic liquid dimethyldinonylammonium bromide (DMDNAB). The methods were compared to each other. Better separation was achieved with DMDNAB as the flow modifier. Method development was done using a fused silica capillary (61 cm x 50 microm i.d.). Optimization was …

Evaluation of dynamic microbial communities in a styrene-degrading biotrickling filter using 16S rDNA tag pyrosequencing and denaturing gradient gel …

2014

Accurately characterizing microbial communities within bioreactors undergoing dynamic operating conditions is an essential first step towards understanding the relationship between microbial community structure and bioreactor performance. A detailed assessment of the changes in microbial populations within a styrene-degrading biotrickling filter was carried out using samples collected at multiple time points ranging from 21 to 155 days of biotrickling filter operation. Examination of microbial populations was conducted by 16S rDNA tag pyrosequencing and denaturing gradient gel electrophoresis (DGGE). Validation of pyrosequencing results was performed by quantitative polymerase chain reactio…

CAPILLARY ELECTROPHORESIS | Crop-Protecting Agents

2007

Capillary eletrophoresis (CE) is becoming an advantageous technique for determining crop protecting agents as a result of its simplicity and high separation efficiency. Controversely, inappropriate limits of detection (LODs) and a lack of selective detectors restrict its applications. The present article provides a general idea of recent advances in off-column and on-column approaches to trace enrichment in analyzing real samples, and recapitulates the determination of crop-protecting agents by conventional CE as well as by emerging techniques, such as CE-laser induced fluorescence (LIF) or CE-mass spectrometry (MS). The usefulness of these approaches in food and environmental applications …

Analytical Techniques for Furosemide Determination

2006

Abstract Due to the clinical importance of furosemide, a large number of analytical procedures to detect the presence of this drug in pharmaceutical and physiological samples has been developed. In this manuscript, a review of the most frequent analytical techniques described to determine furosemide is presented. Special attention has been paid to spectrophotometric and chromatographic techniques, but also to relevant methods using capillary electrophoresis or flow‐injection analysis, as well as the detection modes coupled to these techniques. The review also focuses on the different degradation pathways of the drug and cautions to prevent it, otherwise rarely or confusedly mentioned in the…

Analysis of Alkaloids by Capillary Electrophoresis and Capillary Electrophoresis - Electrospray Mass Spectrometry

1998

Improvement of analytical methods in post‐market monitoring of food additives and testing of the improved methods (OC/EFSA/DCM/2012/04): Interim repo…

2014

Miniaturized liquid chromatography coupled on-line to in-tube solid-phase microextraction for characterization of metallic nanoparticles using plasmo…

2018

Abstract This tutorial aims at providing guidelines for analyzing metallic nanoparticles (NPs) and their dispersions by using methods based on miniaturized liquid chromatography with diode array detection (MinLC-DAD) and coupled on-line to in-tube solid-phase microextraction (IT-SPME). Some practical advice and considerations are given for obtaining reliable results. In addition, this work outlines the potential applications that set these methodologies apart from microscopy-related techniques, dynamic light scattering, single particle ICP-MS, capillary electrophoresis, field-flow fractionation and other chromatographic configurations, which are discussed and mainly seek to accomplish size …