AQUEOUS ALKYLCHLOROFORMATE DERIVATIZATION AND SOLID-PHASE MICROEXTRACTION - DETERMINATION OF AMPHETAMINES IN URINE BY CAPILLARY GAS-CHROMATOGRAPHY

The alkylchloroformate derivatisation and solid-phase microextraction of amphetamine and methamphetamine directly in urine samples prior to capillary gas chromatographic analysis is described. The alkylchlorofo rmate reagent was added to the urine sample, which was adjusted to pH 10.8, and an internal standard was added. The resulting products were water-stable carbamates that were extracted without organic solvent. T he polydimethylsiloxane coated fibre was inserted into the modified sa mple and agitated for 14 min. The fibre with the extracted derivatisat ion products was injected into the capillary gas chromatograph. The ex tracted carbamates were evaporated at 300 degrees C in the split-split less injection port of the gas chromatograph, separated on a methylsil icone capillary column and detected by either a nitrogen-phosphorus de tector or by mass spectrometry. The method was shown to be reproducibl e with a detection limit of 50 ng/ml of amphetamine and methamphetamin e in urine. (C) 1997 Elsevier Science B.V.