Phenylpyruvic acid in urine

Abstract

The method of The, Fleury And Vink for the determination of phenylpyruvic acid (PPA) in urine is modified by measuring the extinction after the green colour with ferric chloride has faded, and subtracting this extinction from that found initially. More accurate values are obtained and low PPA values can be measured. The determination of PPA by taking increasing quantities of urine (up to 5 ml) is an advantage over a single PPA determination. The graphs give detailed information on the PPA-contents of urine and on the amount of inhibitory substances.