Chiral separation and quantification of R/S-amphetamine, R/S-methamphetamine, R/S-MDA, R/S-MDMA, and R/S-MDEA in whole blood by GC-EI-MS

Abstract

The enantioselective composition of the amphetamines is of interest, as the enantiomers show differences in their pharmacological effects and several methods for chiral separation of amphetamines have been described. Only a few methods have used whole blood as matrix and none of these separates both classic amphetamines (amphetamine and methamphetamine) and designer amphetamines (MDA, MDMA and MDEA). The aim of this study was, therefore, to develop a method for enantioselective analysis of AM, MA, MDA, MDMA, and MDEA in whole blood. The amphetamines were extracted from 0.5 g of whole blood by liquid-liquid extraction. After derivatization with R-MTPCl, the resulting diastereomers were separated by GC on a HP-5MS column and detected by SIM-MS. R-MTPCl was used as derivatization reagent because of the stability of this reagent and good separation of these analytes. Through the method, development time and temperature of the derivatization were optimized, and by admixture of 0.02% triethylamine it became possible to detect the amphetamines in adequately low concentrations as more analytes were derivatized. The method was validated and it was linear from 0.004 to 3 microg/g per enantiomer. The accuracy was within 91-115%, while the repeatability and reproducibility were < or =15% R.S.D. A method suitable for enantioselective separation and analysis of the amphetamines has been achieved, and the method was applied to analysis of whole blood samples originating from traffic and criminal cases and post mortem cases.