Analysis of volatile metabolites in biological fluids by high resulution gas chromatography-mass spectrometry

The work described here includes the development of a new method for concentrating and analysing organic volatiles in body fluids (urine and blood). The concentrating was accomplished by using a suitable solid adsorbent, Tenax GC, to adsorb the volatiles which are present in very small amounts. The analysis was done using high resolution gas-chromatography. The purpose behind the development of such a method is to provide early indications of trace metabolic disorders resulting from pathological conditions. However, certain guidelines had to be established before the analysis and interpretation of profiles from pathological cases could be made. Such guidelines were established by analysing body fluids, urine in particular, of three healthy individuals before, during and after an 80 day period of controlled diet, during which, the different physiological activities of the three individuals were carefully monitored. Results indicated that there were no changes in the profiles of each individual for the period in question. Such "normal" profiles were used for comparison with profiles obtained from pathological samples. Comparison of the "normal" profiles with profiles obtained from the analysis of over fifty samples from diabetic patients gave a clear indication that differences do exist. The complexity of the profiles obtained from analysing urine prompted the analysis of organic volatiles in blood (serum and plasma) which, as was expected had less volatlies and presented a more simplified picture. Simple profiles were also obtained from urine samples by using specific detectors.