Determination of S-nitrosoglutathione in erythrocytes by capillary zone electrophoresis

A method for separation and quantification of S-nitrosoglutathione in red c ell extracts by capillary electrophoresis is reported. The method is based on the direct analysis of the metaphosphoric acid erythrocyte extract conta ining diethylenetriaminepentaacetic acid. Optimization of the method is bri efly discussed. Best results in the shortest time were obtained at 25 degre es C, using a coated capillary, 7 kV applied voltage and phosphate sodium 4 0 mmol/L (pH 2.2) as running buffer. Reproducibility, detection limits, and recoveries of S-nitrosoglutathione analyses were checked. The results evid enced that S-nitrosoglutathione is formed in erythrocytes treated with S-ni trosocysteine, a transnitrosating agent. Under our experimental conditions, the contemporaneous detection and quantification of reduced and oxidized g lutathione present in cell extract could also be performed.