Determination of tryptamine derivatives in illicit synthetic drugs by capillary electrophoresis and ultraviolet laser-induced fluorescence detection

A method based on separation by capillary electrophoresis combined with UV-laser induced fluorescence detection (lambda(ex)= 266 nm) was developed for the determination of nine tryptamine derivatives of forensic interest and potential matrix constituents. The composition of the separation electrolyte was optimized with respect to the resolution of solutes of interest and to the sensitivity of fluorescence detection. Native a-cyclodextrin was employed as a complex forming modifier of the electrophoretic separation and fluorescence-enhancing agent. With the help of a stacking procedure, limits of detection of 0.1-6 mu g/L for all analytes were obtained. The repeatability for the peak area (at a concentration of the analyte about 100 times the LOD) was less than 2.3% RSD. A second HPLC method was developed, and its analytical parameters were evaluated for an estimation of the accuracy of the CE-LIF method and for method comparison. The results of the determination of tryptamine derivatives in the samples of forensic interest obtained with the two independent methods are in good agreement.