Analysis of Underivatized Amphetamines and Related Phenethylamines with High-Performance Liquid Chromatography-Atmospheric Pressure Chemical Ionization Mass Spectrometry

Abstract

Amphetamine, methamphetamine, illicit designer phenethylamines (MDA, MDEA, MDMA, MBDB, and BDMPEA), and other phenethylamines (benzyl-1-phenylethylamine, cathinone, ephedrine, fenfluramine, norfenfluramine, phentermine, 1-phenylethylamine, phenylpropanolamine, and propylhexedrine) were extracted from serum using a solid-phase extraction procedure. The extracts were examined with high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS). The drugs were separated on ODS column in acetonitrile/50 mM ammonium formate buffer (pH 3.0) (25:75) as a mobile phase. Full-scan mass spectra of drugs examined by means of APCI with collision-induced dissociation showed protonated molecular ions and fragments typical for particular drugs. LC-APCI-MS allowed an unequivocal differentiation of all drugs involved. The quantitation was performed using selected ion monitoring of protonated molecular ions and fragments of drugs involved and their deuterated analogues. The limits of detection ranged from 1 to 5 microg/L serum, and the recoveries ranged from 58 to 96%. A linear response was observed for all drugs in the range from 5 to 500 microg/L. The method was applied for routine determination of amphetamine, MDMA, MDA, and MDEA in one run. Solid-phase extraction used assured simultaneous isolation of various groups of basic drugs of forensic interest (opiates, cocaines, phenethylamines, and benzodiazepines) from biofluids.