Determination of six amphetamine-type stimulants in urine samples using electro-enhanced single drop microextraction-gas chromatography

: A method for the simultaneous determination of six amphetamine-type stimulants (ATSs) in urine by electro-enhanced single drop microextraction-gas chromatography (EE-SDME-GC) with a flame ionization detector (FID) was developed. The influences of the EE-SDME parameters on the extraction efficiencies were investigated. The 5 mL-samples at pH 7 were extracted with 2 mu L dichloromethane for 3 min under an applied potential of -2.5 V. The analysis was performed on a HP-5 capillary column (30 mx0. 32 mmx0. 25 mu m) using a flame ionization detector. The six ATSs were linear in the range of 20-1 000 mu g/L with correlation coefficients (r) between 0.989 and 0. 997. The limits of detection (S/N= 3) of the six ATSs ranged from 3. 2 to 7. 6 mu g/L. The recoveries of the six ATSs in the spiked urine samples were 91. 6%-111. 2%, and the relative standard deviations were 2. 9%-6. 2% (n=3) at three spiked levels of 50, 100 and 500 mu g/L. This method was rapid, sensitive, reliable, easily-operated and environment-friendly for the determination of the ATSs in urine samples.