title: Differentiation of side chain isomers of ring-substituted amphetamines using gas chromatography/infrared/mass spectrometry (GC/IR/MS).
abstract: Common analytical methods used for identifying samples obtained from clandestine laboratories were evaluated for their ability to differentiate between possible amphetamine isomers and homologs. A series of ring-substituted (4-methyl, 4-methoxy, and 3,4-methylenedioxy) amphetamine and N-methylphenethylamine isomers was analyzed using color tests, thin-layer chromatography, gas chromatography/mass spectrometry (GC/MS) and GC/infrared (GC/IR). The N-acetyl derivatives of the isomers were analyzed using GC/IR/MS. GC/IR/MS readily differentiated the 4-methylphenylalkylamine isomers. MS and IR spectra were also obtained for each pair of the 4-methoxyphenylalkylamine isomers and the 3,4-methylenedioxyphenylalkylamine isomers, but differentiation via GC/IR/MS was difficult. The N-acetyl derivatives of each pair of isomers could be readily differentiated using GC/IR/MS. Good library researchable spectra for N-acetylamphetamine could be obtained for IR identification with 10 ng (on-column) and MS identification with 2 ng. The spectrometrically independent IR and MS data obtained for the N-acetyl derivatives indicated that the combination of GC/IR/MS can add a significant level of confidence in the analysis of ring-substituted arylalkylamines.
authors.affiliation: Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond.
authors.forename: W H
authors.initials: WH
authors.lastname: Soine
authors.forename: W
authors.initials: W
authors.lastname: Duncan
authors.forename: R
authors.initials: R
authors.lastname: Lambert
authors.forename: R
authors.initials: R
authors.lastname: Middleberg
authors.forename: H
authors.initials: H
authors.lastname: Finley
authors.forename: D J
authors.initials: DJ
authors.lastname: O'Neil
mesh_terms: D000662:Amphetamines / Q000737:chemistry*; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D007536:Isomerism; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared
chemical_list: D000662:Amphetamines