Abstract Galactosemia is a potentially fatal disease resulting from a deficiency of galactose-1- phosphate uridyl transferase. In order to perform mechanistic studies designed to elucidate further the etiology of the disease, we required a method to monitor 13 C enrichment in plasma galactose following a single oral dose or intravenous infusion of [1-13 C] galactose. Determinations of plasma [13 C] galactose enrichment requires methodolgy with ...