DEVELOPMENT OF A SCREENING METHOD FOR THE DETERMINATION OF VOLATILE ORGANIC-COMPOUNDS IN BODY-FLUIDS AND ENVIRONMENTAL-SAMPLES USING PURGE-AND-TRAP GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

A sensitive screening method with low sample consumption is presented for the simultaneous determination of 48 volatile organic compounds (VOCs) by capillary gas chromatography with flame ionization detection (FID) or mass spectrometric ion trap detection (ITD). The method is applicable to body fluids (blood, urine and human milk) and environmental samples (well water and waste water). Sample preparation and introduction are performed with a purge and trap system. For low-concentration analytes this has the advantage of including an enrichment step prior to gas chromatographic separation. Four different media in combination are used for the adsorption of the VOCs. The carrier gas purges the compounds through these media during the adsorption step and the subsequent thermodesorption step is performed in the reversed direction. From whole blood the VOCs are adsorbed within 15 min at 40-degrees-C with helium as a purge gas. For desorption the tube is heated to 250-degrees-C. Forty-eight compounds, both non-halogenated aromatic and chlorinated and brominated aliphatic and aromatic VOCs, were separated by two capillary columns with both FID and an ITD instruments in parallel with a chromatographic run time of 28 min per sample. Detailed reproducibility, precision and accuracy data are given. Applications to both body fluids and water samples are presented. The limit of detection is better than 0.1 mug l-1 for most of the compounds. Compared with the static headspace technique for some VOCs this method is 100 times more sensitive.