The role of organic volatile profiles in clinical diagnosis.

The organic volatile constituents of biological fluids contain clinically useful diagnostic information for the recognition of metabolic disorders in man. To gain access to this information, it was necessary to develop the methodology for reproducibly stripping the trace concentrations of volatiles from biological fluids (dynamic headspace, gas phase-stripping, solvent extraction, and the transevaporator technique), to separate the complex extracts by high-resolution capillary column gas chromatography, and to develop computer-aided data-handling and pattern-recognition techniques for analyzing the immense amount of information generated. The normal and pathological organic volatiles identified by gas chromatography--mass spectrometry in urine, serum, and breast milk are tabulated. Clinical applications of the above techniques to the study and diagnosis of diabetes mellitus, respiratory virus infection, renal insufficiency, and cancer are described.