The role of the laboratory in the investigation of solvent abuse.

1 A wide range of compounds which may be abused by inhalation such as butane, the halons, 1,1,1-trichloroethane, trichloroethylene and toluene can be detected and identified in blood specimens by means of headspace gas chromatography. Quantitative analysis of a number of the less volatile compounds of interest may also be accomplished. 2 The measurement of the urinary concentrations of benzoic and hippuric acids (metabolites of toluene) and of the toluric acids (metabolites of the xylenes) by high performance liquid chromatography may provide useful information. In general, a hippurate/creatinine ratio of greater than 1 is indicative of recent toluene exposure. 3 Analysis of the product abused by vapor-phase infra-red spectrophotometry and/or gas chromatography may also be valuable, especially since manufacturers' data as to the constituents of a given product are not always accurate. 4 Toxicological analyses can provide clinically valuable diagnostic information where inhalational abuse of volatile substances is suspected, and provide the only unequivocal means of defining the agent(s) abused by a given population.