Optimization of separation and online sample concentration of N,N-dimethyltryptamine and related compounds using MEKC

The optimal separation conditions and online sample concentration for N,N-dimethyltryptamine (DMT) and related compounds, including α-methyltryptamine (AMT), 5-methoxy-AMT (5-MeO-AMT), N,N-diethyltryptamine (DET), N,N-dipropyltryptamine (DPT), N,N-dibutyltryptamine (DBT), N,N-diisopropyltryptamine (DiPT), 5-methoxy-DMT (5-MeO-DMT), and 5-methoxy-N,N-DiPT (5-MeO-DiPT), using micellar EKC (MEKC) with UV-absorbance detection are described. The LODs (S/N = 3) for MEKC ranged from 1.0 [tilde] 1.8 μg/mL. Use of online sample concentration methods, including sweeping-MEKC and cation-selective exhaustive injection-sweep-MEKC (CSEI-sweep-MEKC) improved the LODs to 2.2 [tilde] 8.0 ng/mL and 1.3 [tilde] 2.7 ng/mL, respectively. In addition, the order of migration of the nine tryptamines was investigated. A urine sample, obtained by spiking urine collected from a human volunteer with DMT, was also successfully examined.