Mixed-mode solid-phase extraction procedures for the determination of MDMA and metabolites in urine using LC-MS, LC-UV, or GC-NPD.
A solid-phase extraction (SPE) procedure was developed for the liquid chromatographic-mass spectrometric (LC-MS) analysis of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolites 3,4-methylenedioxyamphetamine (MDA) and N,alpha-dimethyl-(3-methoxy-4-hydroxybenzene) (HMMA) ethanamine in urine. The procedure, with modifications, was also demonstrated using LC-UV and GC-nitrogen-phosphorus detection (NPD). A mixed-mode cation exchange SPE cartridge was effective for both reducing matrix impurities and for preconcentrating the analytes for the analysis. The concentration range investigated spanned from 0.10 to 20 microg/mL with recoveries ranging from 88% to 108% for all analytes using LC-MS. Both LC methods and the GC method allow for complete resolution of MDMA, MDA, and HMMA, as well as the internal standards (MDMA-d5 and 3,4-methylenedioxypropylamphetamine) in less than 10 min. Lower limits of quantitation (LLOQ) for the LC-MS method were 0.1 microg/mL for MDMA and MDA and 0.04 microg/mL for HMMA. Compared with LC-UV and GC-NPD, the LC-MS method requires the least amount of sample manipulation and provided the highest sample throughput. GC-NPD gave comparable selectivity, but the extra sample manipulation steps required contributed to lower recovery, lower precision, and increased time for the analysis. LC-MS analysis demonstrated better selectivity for the determination of HMMA in incurred samples compared with LC-UV analysis.
Jenkins
Kevin M
KM
Waters Corporation, 34 Maple Street, Milford, Massachusetts 01757, USA.
Young
Michael S
MS
Mallet
Claude R
CR
Elian
Albert A
AA
D002849:Chromatography, Gas / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006213:Hallucinogens / Q000652:urine*; D006801:Humans; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000031:analogs & derivatives / Q000652:urine*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D015813:Substance Abuse Detection / Q000379:methods*
D006213:Hallucinogens; D018817:N-Methyl-3,4-methylenedioxyamphetamine