Fluorometric determination of phenylpyruvic acid with 1,4-dimethyl-3-carbamoylpyridinium chloride.

Abstract
A fluorometric method for the determination of phenylpyruvic acid (PPA) has been established. Benzaldehyde formed from PPA by alkaline decomposition is quantified by means of its fluorogenic reaction with 1, 4-dimethyl-3-carbamoylpyridinium chloride. PPA can be determined in the range of 0.1-3 nmol/50 μl with the relative standard deviation of 4.0-4.1%. About 70% recovery was obtained when a urine sample (0.1 ml) added with 5 nmol of PPA was extracted and then determined by the proposed method. The method should be useful for the biochemical diagnosis of phenylketonuria.