Determination of rhodanese enzyme activity by capillary zone electrophoresis

A new sensitive method has been developed for the determination of rhodanes e activity. The enzymatic reactions were carried out directly in thermostat ted autosampler vials and the formation of SCN- was monitored by sequential capillary zone electrophoretic runs. The determinations were performed in a 75-mu m fused-silica capillary using 0.1 M beta-alanine-HCl (pH 3.50) as a background electrolyte, a separation voltage of 18 kV (negative polarity) , a capillary temperature of 25 degrees C and direct detection at 200 nm. S hort-end injection or long-end injection procedures were used for sample ap plication. The method is rapid, able to be automated and requires only smal l amounts of sample and substrates, which is especially important in the ca se of highly toxic cyanide. The developed capillary electrophoretic method also has great potential for thiocyanate determinations in other applicatio ns. (C) 1999 Elsevier Science B.V. All rights reserved.