Simultaneous determination of methamphetamine, 3,4-methylenedioxy-N-methylamphetamine, 3,4-methylenedioxy-N-ethylamphetamine, N,N-dimethylamphetamine, and their metabolites in urine by liquid chromatography-electrospray ionization-tandem mass spectrometry.
A liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) method was developed and validated for the simultaneous detection and quantification of seven amphetamine derivatives (amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxy-N-amphetamine (MDA), 3,4-methylenedioxy-N-methamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), N,N-dimethylamphetamine (DMA), and N,N-dimethylamphetamine-N-oxide (DMANO)) in human urine. Seven deuterium-labeled compounds were prepared for use as internal standards to quantify the analytes. One milliliter of urine was combined with 1 mL of 0.2 M sodium carbonate buffer solution (pH 9.0) before solid phase extraction (SPE). An Oasis HLB SPE column followed by chromatographic separation on a Capcell Pak C18 MG-II column (150 x 2.0 mm I.D., 5 microm) and electrospray mass spectrometry with multiple reaction monitoring were used for selective and sensitive detection. The use of ammonium formate (5 mM, pH adjusted to 4.0 with formic acid, Solvent A) and acetonitrile (Solvent B) as the mobile phase at a flow rate of 230 microL/min was found to be the most effective for the separation. The linear ranges were 5.0-1000 ng/mL for AP, MDA, MDMA, MDEA, DMA, and DMANO and 10.0-1000 ng/mL for MA, with good correlation coefficients (r2 > 0.996). The intra-day, inter-day, and interperson precisions were within 14.6%, 12.1% and 15.5%, respectively. The intra-day, inter-day, and interperson accuracies were between -11.6 and 9.0%, -7.9 and 2.3%, and -13.2 and 4.3%, respectively. The limits of detection (LODs) for each analytical compound were lower than 1.95 ng/mL. The recovery ranged from 72.3 to 103.3%. The applicability of the developed method was examined by analyzing several urine samples from confirmed drug abusers.
Kim
Jin Young
JY
Drug Analysis Laboratory, Forensic Science Division, Supreme Prosecutors' Office, Seoul, 137-730, Korea. paxus@spo.go.kr
Cheong
Jae Chul
JC
Ko
Beom Jun
BJ
Lee
Sang Kyu
SK
Yoo
Hye Hyun
HH
Jin
Changbae
C
In
Moon Kyo
MK
D015104:3,4-Methylenedioxyamphetamine / Q000031:analogs & derivatives / Q000652:urine; D000662:Amphetamines / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008694:Methamphetamine / Q000031:analogs & derivatives / Q000652:urine; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000652:urine; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization
D000662:Amphetamines; D007202:Indicators and Reagents; D008694:Methamphetamine; D015104:3,4-Methylenedioxyamphetamine; C003714:dimethylamphetamine; D018817:N-Methyl-3,4-methylenedioxyamphetamine; C051800:3,4-methylenedioxyethamphetamine