Microdetermination of tryptophan in compounded poultry rations.

A reliable method for the microdetermination of tryptophan in compounded poultry rations has been developed. Samples are hydrolyzed with Ba (OH)2, and the hydrolysate is passed through a Dowex-50 column to remove the salts and soluble carbohydrates. N-1-Naphthylethylenediamine is added to the purified feed hydrolysate, and color is read at 530 nm.