A simple procedure for basic hydrolysis of proteins and rapid determination of tryptophan using a starch column

The use of an alkali resistant centrifuge tube as a liner for an evacuated glass apparatus for the hydrolysis of proteins by sodium hydroxide is deseribed. The analysis of tryptophan is made with an automatic amino acid analyzer in which the medium-length resin column is replaced by a potato starch column. Tryptophan in a basic hydrolyzate can be determined within 2 hr. This procedure gave high recoveries of free tryptophan and of tryptophan added to proteins. Some proteins and food stuffs were analyzed by this method to show its applicability. This method can be used for milligram quantities of protein.