Determination of organic acids and phosphate in soil aqueous extracts by capillary zone electrophoresis

Abstract

Organic acids and phosphate were determined in soil aqueous extracts by capillary zone electrophoresis using indirect UV detection. The electrolyte system was 10 mM sodium benzoate with 0.5 mM tetradecyltrimetyl-ammonium bromide as flow modifier at pH 4.0, pH 4.5, or pH 5.0. This methodology was adequate to determine organic acids and phosphate in soil samples, but the major inorganic anions interfered in the determination. In all the samples of soil extracts, the presence of phosphate was detected. Acetate was found in most of the samples and lactate and formate in some of them.