| Abstract |
Room temperature ionic liquids (ILs) have already been shown to provide efficient extraction media for several systems, and to capture volatile compounds, namely opiates. In this work, a novel, contactless, artefact-free extraction procedure for the removal of (9)-tetrahrydrocannabinol (THC) from the surface of human hair is presented. To prepare in vitro cannabinoids-contaminated hair, samples were flushed with hashish smoke for 7h. The decontamination experiments were carried at 100 degrees C for 24h, according to the procedure previously described. Fifty-three ILs were screened and presented decontamination efficiencies ranging from 0 to 96 \%. Although the majority of the ILs presented efficiencies above 90\%, the 1-ethanol-3-methyl tetrafluoroborate (96\%) was chosen for further process optimization. The Design of Experiments results demonstrated that all studied variables were significant for the process and the obtained optimum conditions were: 100 degrees C, 13h and 175mg of IL. In the work of Perrotin-Brunel et al. (J. Mol. Struct. 2011, 987, 67), it is demonstrated that, at 100 degrees C, full conversion of tetrahydrocannabinolic acid (THCA) into THC is obtained after 60min. Since our decontamination takes place over 13h at 100 degrees C, full conversion of THCA into THC is expected. Additionally, our method was compared with the method proposed by Cairns et al. (ForensicSci. Int. 2004, 145, 97), through the analysis of 15 in vitro contaminated hair samples. The results demonstrated that with our method a mean extraction efficiency of 11 \% higher was obtained. Copyright (c) 2016 John Wiley \& Sons, Ltd. |
