Detection and assay of cis- and trans-isomers of 4-methylaminorex in urine, plasma and tissue samples

The 4-methylaminorex (4-MAX) is an amphetamine-related psychostimulant drug that has appeared on the clandestine market with a street name of "U4Euh". This compound exists as four stereoisomers, trans-4R,5R, trans-4S,5S, cis- 4R,5S and cis-4S,5R, of which the cis forms have been classified as Schedul e I substances in the US. The increasing variety of designer drugs has high lighted the importance of detection, identification, and quantitative measu rement of these drugs, including 4-MAX, in biological samples. In the prese nt study, the isomers of 4-MAX were detected in urine of rats treated with the drugs by some but not all of the on-site immunoassays tested, mainly as amphetamine or methamphetamine. To facilitate identification of 4-MAX by l aboratories specialized in drug analysis, the electron-ionization mass spec trum and TLC data for underivatized 4-MAX using a routine laboratory drug-s creening procedure is provided. In addition, a GC/MS method is described fo r the quantitative determination of cis- and trans-4-MAX as tert-butyldimet hylsilyl-derivatives in plasma, urine and tissue. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.