Analytical Sciences


Abstract − Analytical Sciences, 34(12), 1419 (2018).

Colorimetric Determination of (Aminoalkyl)indole-containing Synthetic Cannabimimetics
Hasan DURMUS,* Selen DURMAZEL,* Aysem ÜZER,* Bahar GÖKDERE,* Erol ERÇAG,** and Resat APAK*,***
*Department of Chemistry, Faculty of Engineering, Istanbul University-Cerrahpasa, Avcilar, Istanbul 34320, Turkey
**Aytar Caddesi, Fecri Ebcioglu Sokak, No. 6/8, Levent, Istanbul 34340, Turkey
***Turkish Academy of Sciences (TUBA), Piyade St. No. 27, Çankaya, Ankara 06690, Turkey
Cannabis is an important industrial plant, in addition to its illicit drug use. Compound Δ9-THC (Δ9-tetrahydrocannabinol) is mainly responsible for the hallucinogenic effect on humans. The aminoalkylindole group cannabimimetics targets at the same physiological receptors to mimic the analgesic effects of Δ9-THC. Since there is no reliable colorimetric test to detect these synthetic cannabimimetics on site, a simple colorimetric assay for (aminoalkyl)indole group-containing drugs was developed, based on the silica/sulfuric acid-catalyzed Ehrlich reaction of (aminoalkyl)indoles with p-dimethylaminobenzaldehyde. The electrophilic substitution reaction of indoles with carbonyl compounds resulting in the formation of bis(indolyl)alkanes in an acid-catalyzed reaction has been used for the first time for their spectrophotometric determination by color change from yellow to purple/blue. The method was statistically validated against liquid chromatography tandem mass spectrometry, and applied to certain (aminoalkyl)indole derivatives, with 0.5 – 2.5 μg mL−1 detection limits for AM-2201, JWH-081, MAM-2201, JWH-018, JWH-210, JWH-122, 5F-PB-22 and XLR-11.