Identification of drugs, drug metabolites, and other compounds in urine by permethylation and gas-phase analysis.

A small aliquot of urine (50-200 mul) is evaporated to dryness, the residue permethylated with the methylsulfinylmethide carbanion and methyl iodide, and the product mixture separated and analyzed by GC and GC-MS. Certain drugs (especially the anticonvulsants), drug metabolites, mono-, di-, and trisaccharides, and organic acids, including fatty acids and glucuronides, can be identified in the mixture. The technique is probably useful mainly as a screening method for the detection of any of these types of compounds in urine.