Supported liquid extraction (SLE) for the analysis of methylamphetamine, methylenedioxymethylamphetamine and delta-9-tetrahydrocannabinol in oral fluid and blood of drivers

Method validation and recoveries were carried out on drug free ante mortem blood and DDS buffer solution provided by Alere, Australia. Recoveries above 80% were achieved for MA and MDMA at a concentration of 25 ng/mL, whilst recoveries of greater than 65% were achieved for THC at 4.5 ng/mL. Accuracy and precision were acceptable down to the LLOQ for all three analytes (5, 5 and 1 ng/mL for MA, MDMA and THC, respectively). Mean matrix effects were 1.0, 0.97 and 0.78 in DDS buffer and 0.96, 0.96 and 0.62 in blood for MA, MDMA and THC, respectively. Linearity was achieved up to 1250 ng/mL for MA and MDMA, and 112 ng/mL for THC (r2 > 0.999 for all analytes). The method is designed for easy transfer to an automated liquid handling platform.