Colorimetric method for estimating methylmalonic acid in urine.

Abstract

A colorimetric method for the estimation of methylmalonic acid in urine is described. The method is suitable for use in clinical pathology laboratories. Acidified urine is saturated with ammonium sulfate and extracted with ethanol and ether, and the extract is purified using a strongly basic ion exchange resin. The methylmalonic acid is eluted and a color developed by coupling with diazotized p-nitroaniline.