Capillary electrophoresis coupled with chloroform-acetonitrile extraction for rapid and highly selective determination of cysteine and homocysteine levels in human blood plasma and urine.

A rapid and selective method has been developed for highly sensitive determination of total cysteine and homocysteine levels in human blood plasma and urine by capillary electrophoresis (CE) coupled with liquid-liquid extraction. Analytes were first derivatized with 1,1'-thiocarbonyldiimidazole and then samples were purified by chloroform-ACN extraction. Electrophoretic separation was performed using 0.

Plasma low-molecular-weight thiol/disulphide homeostasis as an early indicator of global and focal cerebral ischaemia.

Objective: Recent studies have shown that cerebral ischaemia causes not only local, but also systemic oxidative stress. This leads to oxidation of thiol-containing compounds, including low-molecular-weight thiols (cysteine, glutathione, homocysteine and others). Therefore, the aim of this work was to verify the hypothesis that the thiol/disulphide homeostasis of low-molecular-weight thiols is disturbed in the early stages of cerebral ischaemia.

Application of the capillary electrophoresis method for the study of plasma proteins homocysteinylation.

Purpose: Purpose. This article describes the use of capillary electrophoresis with UV detection to determine the ratio of protein-bound homocysteine and cysteine concentrations in human plasma.

Methods: Plasma samples were reduced with dithiothreitol and derivatized by thiocarbonyldiimidazole before being filtered again for purification of proteins.

Capillary electrophoresis and phenylboronic acid solid phase extraction for the determination of S-adenosylmethionine/S-adenosylhomocysteine ratio in human urine.

An approach that allows direct analysis of the ratio of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) by using CE is presented. The analytes were extracted on phenylboronic acid phase and eluted with 100 mmol/L HCl. CE separation of the analytes took place in the transient isotachophoresis mode with addition of NaCl and meglumine to the samples.

Capillary electrophoresis coupled with 1,1'-thiocarbonyldiimidazole derivatization for the rapid detection of total homocysteine and cysteine in human plasma.

A simple and rapid approach is described for the determination of total plasma cysteine and homocysteine using capillary electrophoresis. Human plasma samples were reduced with dithiothreitol and then processed with 1,1'-thiocarbonyldiimidazole in acetonitrile. After centrifugation, the sample supernatant was injected directly into a capillary by applying negative voltage and analytes were stacked after alkaline post-injection.