High-throughput toxicological analysis of Methamphetamine, MDA and MDMA from human plasma by LC-MS/MS

A new LC-MS/MS method quantifies methamphetamine (MA), MDMA, and MDA in human plasma quickly and inexpensively. The method uses a small plasma sample (0.2 mL), simple precipitation with perchloric acid, and a 2.5-minute instrument run. It shows good linearity, precision, and accuracy over the ranges 2.03–169.04 ng/mL for MA, 2.08–173.44 ng/mL for MDA, and 2.48–206.92 ng/mL for MDMA. Recoveries range from 88.3% to 110.4%. The method is simpler and faster than comparable techniques and suitable for forensic toxicology analyses.

Study at a glance

Abstract

A new high-throughput liquid chromatography coupled with mass spectrometry (LC-MS/MS) method for the quantification of methamphetamine (MA), methylendioximeth-amphetamine (MDMA) and methylendioxiamphetamine (MDA) in human plasma was developed and validated. The separation was performed on a Zorbax SB-C18 column under isocratic conditions using a 15:85 (v/v) mixture of methanol and 0.1% (v/v) formic acid in water at 45oC with a flow rate of 1 mL/min. The detection was performed in MRM mode using an ion trap MS equipped with an APCI ion source, positive mode. The ion transitions monitored were m/z 150→ m/z (91+119) for MA, m/z 180→ m/z 163 for MDA and m/z 194→ m/z 163 for MDMA, respectively. The human plasma samples (0.2 mL) were precipitated using 7% perchloric acid in water (0.1 mL) and aliquots from supernatants obtained after centrifugation were directly injected into the chromatographic system. The method shows a good linearity (r > 0.996), precision and accuracy (< 13%) over the concentration ranges of 2.03-169.04 ng/mL for MA, 2.08-173.44 ng/mL for MDA, and 2.48-206.92 ng/mL for MDMA, respectively. The recoveries were between 88.3-110.4%. The method is not expensive, it needs a minimum time for plasma sample preparation and has a run-time of 2.5 min for instrument analysis (retention times of MA, MDA and MDMA were 1.8, 1.9 and 2.0 min, respectively). The developed and validated LC-MS/MS method is very simple and more rapid than other similar methods. It can be useful for the rapid quantification of MA, MDMA and MDA in human plasma in forensic toxicology analyses.