Two-Dimensional Gas Chromatography/Electron-Impact Mass Spectrometry with Cryofocusing for Simultaneous Quantification of MDMA, MDA, HMMA, HMA, and MDEA in Human Plasma
Erin A Kolbrich, Ross H. Lowe, Marilyn A. Huestis
Clinical Chemistry December 19, 2007 DOI: 10.1373/clinchem.2007.096800 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Method development and validation Peer reviewed |
|---|---|
| Topics | MDMA |
| Keywords | Analyte Detection limit Selected ion monitoring Gas chromatography–mass spectrometry Solid phase extraction Pharmacokinetics Calibration curve Extraction chemistry Pharmacology |
| Citations | 36 |
| Key points | The two-dimensional GC/MS assay provides low limits of quantification (1.0 μg/L for MDA, 2.5 μg/L for MDEA, MDMA, HMMA, and HMA) with high extraction efficiency, recovery, and precision for simultaneous analysis of these compounds in human plasma. |
Abstract
Abstract
Background: 3,4-Methylenedioxymethamphetamine (MDMA, or Ecstasy) is a popular recreational drug. Analysis of MDMA and metabolites in human plasma, particularly in pharmacokinetic studies, requires low limits of quantification. Two-dimensional GC/MS with cryofocusing is a chromatographic technique recognized for its increased selectivity and resolution.
Methods: This method simultaneously quantifies 3,4-methylenedioxyethylamphetamine (MDEA), MDMA, and its metabolites, 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and 4-hydroxy-3-methoxyamphetamine (HMA) in human plasma. With hydrochloric acid, we hydrolyzed 1 mL plasma, fortified with internal standard. Analytes were subjected to solid-phase extraction, derivatized with heptafluorobutyric acid anhydride, and quantified using cryofocused 2-dimensional GC/MS operated in electron-impact selected ion-monitoring mode.
Results: Limits of quantification were 1.0 μg/L for MDA and 2.5 μg/L for MDEA, MDMA, HMMA, and HMA. Calibration curves were linear to 100 μg/L for MDA and HMA and to 400 μg/L for MDEA, MDMA, and HMMA, with r2 > 0.997. At 3 concentrations spanning the linear dynamic range of the assay, mean overall extraction efficiencies from plasma were ≥85% for all compounds of interest. Recoveries were 85.6% to 107.2% of target, and intra- and interassay imprecision (CV) was <8.5% for all drugs at 3 concentrations within the range of the assay. None of the 66 exogenous compounds tested interfered with analyte quantification.
Conclusions: This GC/MS assay provides low limits of quantification for simultaneous determination of MDEA, MDMA, and metabolites MDA, HMMA, and HMA in human plasma. The 2D chromatographic system should be suitable for application to other analytes and to other complex matrices.