Headspace sampling and GC analysis of volatile urinary metabolites

A method requiring only 1 to 3 ml of sample is developed for the analysis of volatile metabolites in urine. Trace volatiles are stripped with helium and concentrated on Porapak Q and activated charcoal traps in series. Volatiles are thermally desorbed into a fused silica capillary column for analysis by gas chromatography. Variables affecting the process are studied. Profiles of untreated and acid hydrolyzed urine are presented.