GC–MS, GC–MS/MS and GC-IR differentiation of carbonyl modified analogues of MDPV

Abstract

A combination of GC–MS, GC–MS/MS and GC-IR techniques can be used to differentiate 2,3- and 3,4-MDPV from the carbonyl modified analogues, aminoalcohols and the corresponding desoxy substituted phenethylamines. These six compounds all yield the identical base peak iminium cation at m/z 126 in their electron ionization mass spectrum. The MS/MS evaluation of the iminium cation fragment yields identical major product ions at m/z 84. Soft ionization via methanol CI-MS confirms the molecular weight for all these compounds. The only peak in the CI-MS for the aminoketones and the desoxy substituted phenethylamines occurs at (M+H)+. The aminoalcohols show a characteristic fragment ion in CI-MS corresponding to the loss of H2O from the (M+H)+. Vapor phase infrared spectra (GC-IR) confirm the aromatic ring substitution pattern via unique absorption in the 1450cm−1 range. In all GC separations the 2,3-methylenedioxy substituted isomer elutes before the analogous 3,4-isomer.