Sensitive Gas Chromatography-Mass Spectrometry Method for Simultaneous Measurement of MDEA, MDMA, and Metabolites HMA, MDA, and HMMA in Human Urine

A sensitive gas chromatography-mass spectrometry method was developed and validated to simultaneously measure MDEA, MDMA, and its metabolites (HMA, MDA, HMMA) in human urine. The method involves acid hydrolysis of 1 mL urine, solid-phase extraction, and derivatization before analysis. Limits of quantification were 25 μg/L for all analytes, with linear calibration up to 5000 μg/L. Extraction efficiencies exceeded 85.5%, and imprecision (coefficient of variation) was below 15% at tested concentrations. The assay meets federal workplace drug testing guidelines for these substances.

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Abstract

Abstract Background: A sensitive gas chromatography-mass spectrometry method was developed and validated for the simultaneous measurement of MDEA, MDMA, and its metabolites, 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy), and its metabolites, 4-hydroxy-3-methoxyamphetamine (HMA), 3,4-methylenedioxyamphetamine (MDA), and 4-hydroxy-3-methoxyamphetamine (HMMA) in human urine. Methods: We hydrolyzed 1 mL urine, fortified with MDMA-d5, MDA-d5, and MDEA-d6, with 100 μL of concentrated hydrochloric acid at 120 °C for 40 min, then added 100 μL 10 N sodium hydroxide and 3 mL phosphate buffer 0.1 N (pH 6.0) were added to hydrolyzed urine specimens before solid-phase extraction. After elution and evaporation, we derivatized extracts with heptafluorobutyric acid anhydride and analyzed with gas chromatography-mass spectrometry operated in EI-selected ion-monitoring mode. Results: Limits of quantification were 25 μg/L for MDEA, MDMA, and its metabolites. Calibration curves were linear to 5000 μg/L for MDEA, MDMA, HMA, MDA, and HMMA, with a minimum r2 > 0.99. At 3 concentrations spanning the linear dynamic range of the assay, mean overall extraction efficiencies from urine were >85.5% for all compounds of interest. Intra- and interassay imprecisions, produced as CV, were <15% for all drugs at 30, 300, and 3000 μg/L. Conclusions: This gas chromatography-mass spectrometry assay provides adequate sensitivity and performance characteristics for the simultaneous quantification of MDEA, MDMA, and its metabolites HMMA, MDA, and HMA in human urine. The method meets and exceeds the requirements of the proposed Substance Abuse and Mental Health Services Administration’s guidelines for federal workplace drug testing of MDEA and MDMA in urine.