Determination of aldehydes in water samples by capillary electrophoresis after derivatization with hydrazino benzene sulfonic acid

A method has been developed for the analysis of environmentally important aldehydes in rain water. The method is based on the derivatization of the aldehydes with hydrazino benzene sulfonic acid, separation of the hydrazones formed by capillary electrophoresis and UV detection at 280 nm. Derivatization was shown to be complete in 15 min at 50 degrees C. The aldehyde derivatives could be separated from each other and from the excess of reagent using a pH 9 berate buffer as background electrolyte, with an analysis time of less than 6 min. The repeatability was better than 0.5 % for the peak mobilities and in the order of 2-5 % for the peak areas. Detection limits of 0.8-3 mu mol L-1 (0.02-0.2 ppm) were obtained. The method was applied for the determination of formaldehyde and acetaldehyde in rain water samples.