Automated determination of ‘Ecstasy’ and amphetamines in urine by SPME and capillary gas chromatography after propylchloroformate derivatisation

Abstract

The determination of amphetamines and their methylenedioxylated analogs in urine by propylchloroformate derivatisation and automated solid-phase microextraction is described. The urine sample was adjusted to pH 10.8 and added propylchloroformate reagent and an internal standard. Derivatisation resulted in water-stable carbamates which were automatically extracted by solid-phase microextraction. A fiber coated with polydimethylsiloxane was inserted into the urine matrix and agitated for 16 min. The fibre with the extracted carbamates was injected into the heated split-splitless injection port of the gas chromatograph where the analytes were evaporated at 300°C, separated on a methylsilicone capillary column and detected by either a nitrogen–phosphorous detector or by mass spectrometry. The method was shown to be highly reproducible and robust with respect to variations in the urine matrices. The detection limits were 5 ng ml −1 of methamphetamine, MDMA and MDEA and 15 ng ml −1 of amphetamine and MDA in urine. The method is a solvent free, automated alternative to traditional methods for determination of the amphetamine and their methylendioxylated analogs in urine.