A general screening and confirmation approach to the analysis of designer tryptamines and phenethylamines in blood and urine using GC-EI-MS and HPLC-electrospray-MS.

A gas chromatography-mass spectrometry method was developed to screen for six designer tryptamines and phenethylamines recently added to the DEA's controlled substances list. The method detects pentafluoropropionic derivatives of AMT, DMT, 2CB, DPT, 2C-T-7, and 5-MeO-DiPT, with detection limits of 5-10 ng/mL and linearity from 50 to 1000 ng/mL. It was successfully applied to blood and urine from suspected AMT intoxications. Confirmation of 5-MeO-DiPT in one subject's urine by liquid chromatography-mass spectrometry yielded a concentration of 229 ng/mL, with linearity from 25 to 1500 ng/mL and a detection limit of 5 ng/mL. Two additional peaks suggested metabolites 5-MeO-iPT and 5-MeO-DiPT-N-oxide.

Study at a glance

Abstract

Recent additions of designer tryptamines and phenethylamines to the Drug Enforcement Administration's schedule of controlled substances necessitate analytical procedures for their detection and quantitation. As specific immunoassays are not currently available and cross-reactivities with existing assays are unknown, a screening method based on gas chromatography-mass spectrometry was developed. The method was capable of measuring the pentafluoropropionic derivatives of a-methyltryptamine (AMT), N,N-dimethyltryptamine (DMT), 4-bromo-2,5-dimethoxy-beta-phenethylamine (2CB), N,N-dipropyltryptamine (DPT), 2,5-dimethyl-4-N-propylthio-beta-phenethylamine (2C-T-7), and 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DiPT). Separation was optimized to allow tentative identification of metabolites, which display common electron impact ionization fragmentation patterns. The screening method gave limits of detection between 5 and 10 ng/mL and demonstrated linearity between 50 and 1000 ng/mL. The method was successfully applied to blood and urine samples in suspected AMT intoxications. Confirmation of 5-MeO-DiPT in one of the subjects' urine was achieved using liquid chromatography-mass spectrometry (LC-MS). Quantitation by selected ion monitoring (SIM) yielded a urinary concentration of 229 ng/mL. The method was linear from 25 to 1500 ng/mL with a correlation coefficient of 0.995. The limit of detection was 5 ng/mL in urine on the LC-MS. Two additional peaks were observed and presumed to be metabolic products reported previously as 5-methoxy-N-isopropyltryptamine (5-MeO-iPT) and 5-methoxy-N,N-diisopropyltryptamine-N'-oxide (5-MeO-DiPT-N-oxide).