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

•This study compares the aminoalcohols and desoxy analogues of 2,3- and 3,4-MDPV.•The precursor ketones and amines were resolved by capillary GC.•Chemical ionization methods confirm the MW for these compounds.•All these compounds yield identical base peak iminium cations and major product ions.•The vapor phase infrared spectra identify the aromatic substitution pattern.

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 1450 cm−1 range. In all GC separations the 2,3-methylenedioxy substituted isomer elutes before the analogous 3,4-isomer.

Graphical abstractStructures of the carbonyl and carbonyl modified analogues of 2,3-MDPV and 3,4-MDPV.Download high-res image (119KB)Download full-size image