Screening for and validated quantification of amphetamines and of amphetamine‐ and piperazine‐derived designer drugs in human blood plasma by gas chromatography/mass spectrometry

A method was developed to screen for and simultaneously quantify classical stimulants (amphetamine, methamphetamine, ethylamphetamine, MDA, MDMA, MDEA, BDB, MBDB) and newer designer drugs (4-methylthioamphetamine, p-methoxyamphetamine, p-methoxymethamphetamine, and several piperazine derivatives) along with two metabolites in human blood plasma. The technique uses gas chromatography/mass spectrometry with selected-ion monitoring after solid-phase extraction and derivatization. The method was linear from 5 to 1000 µg/L for all analytes, with a limit of quantification of 5 µg/L. Accuracy and precision met required limits except for MDBP. The assay was validated and applicable for confirming immunoassay results positive for amphetamines or ecstasy-type designer drugs.

Study at a glance

Abstract

Abstract The classical stimulants amphetamine, methamphetamine, ethylamphetamine and the amphetamine‐derived designer drugs MDA, MDMA (‘ecstasy’), MDEA, BDB and MBDB have been widely abused for a relatively long time. In recent years, a number of newer designer drugs have entered the illicit drug market. 4‐Methylthioamphetamine (MTA), p ‐methoxyamphetamine (PMA) and p ‐methoxymethamphetamine (PMMA) are also derived from amphetamine. Other designer drugs are derived from piperazine, such as benzylpiperazine (BZP), methylenedioxybenzylpiperazine (MDBP), trifluoromethylphenylpiperazine (TFMPP), m ‐chlorophenylpiperazine (mCPP) and p ‐methoxyphenylpiperazine (MeOPP). A number of severe or even fatal intoxications involving these newer substances, especially PMA, have been reported. This paper describes a method for screening for and simultaneous quantification of the above‐mentioned compounds and the metabolites p ‐hydroxyamphetamine and p ‐hydroxymethamphetamine (pholedrine) in human blood plasma. The analytes were analyzed by gas chromatography/mass spectrometry in the selected‐ion monitoring mode after mixed‐mode solid‐phase extraction (HCX) and derivatization with heptafluorobutyric anhydride. The method was fully validated according to international guidelines. It was linear from 5 to 1000 µg l −1 for all analytes. Data for accuracy and precision were within required limits with the exception of those for MDBP. The limit of quantification was 5 µg l −1 for all analytes. The applicability of the assay was proven by analysis of authentic plasma samples and of a certified reference sample. This procedure should also be suitable for confirmation of immunoassay results positive for amphetamines and/or designer drugs of the ecstasy type. Copyright © 2003 John Wiley & Sons, Ltd.