GC-MS Analysis of Ring and Side Chain Regioisomers of Ethoxyphenethylamines

• NCJ Number: 310082
• Journal: Journal of Chromatographic Science Volume: 46 Issue: 8 Dated: September 2008 Pages: 671–679
• Author(s): Tamer Awad; Jack Deruiter; C. Randall Clark
• Date Published: September 2008
• Length: 9 pages
• Grant Number(s): 2006-DN-BX-K016
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)

Annotation

This paper presents the research methodology and findings regarding an evaluation of whether mass spectral differentiation of 3,4-MDMA and its 2,3-regioisomer from the ring substituted ethoxyphenethylamines is possible after the formation of two perfluoroacyl derivatives; and it concludes that gas chromatographic separation on relatively non-polar stationary phases successfully resolves these derivatives.

Abstract

Mass spectral differentiation of 3,4- methylenedioxymethamphetamine (3,4-MDMA), a controlled drug, and its 2,3-regioisomer from the ring substituted ethoxyphenethylamines is possible after formation of the perfluoroacyl derivatives, pentafluoropropionamides (PFPA), and heptafluorobutyrylamides (HFBA). The ring substituted ethoxyphenethylamines constitute a unique set of compounds having an isobaric relationship with 3,4-MDMA. These isomeric forms of the 2-, 3-, and 4-ethoxy phenethylamines have mass spectra essentially equivalent to 3,4-MDMA; all have molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z 58 and 135/136. All the side chain regioisomers of 2-ethoxy phenethylamine having equivalent mass spectra to 3,4-MDMA are synthesized and compared via gas chromatography—mass spectrometry to 2,3- and 3,4- methylenedioxymethamphetamine. The mass spectra for the perfluoroacyl derivatives of the primary and secondary amine regioisomers are significantly individualized, and the side chain regioisomers yield unique hydrocarbon fragment ions at m/z 148, 162, and 176. Additionally, the substituted ethoxymethamphetamines are distinguished from the methylenedioxymethamphet-amines via the presence of the m/z 107 ion. Gas chromatographic separation on relatively non-polar stationary phases successfully resolves these derivatives. (Published Abstract Provided)