Molecularly imprinted polymer for selective determination of [Delta] super(9)-tetrahydrocannabinol and 11-nor-[Delta] super(9)-tetrahydrocannabinol carboxylic acid using LC-MS/MS in urine and oral fluid

The use of molecularly imprinted polymers (MIPs) for solid phase extraction (MISPE) allows a rapid and selective extraction compared with traditional methods. Determination of [Delta] super(9)-tetrahydrocannabinol (THC) and 11-nor-[Delta] super(9)-tetrahydrocannabinol carboxylic acid (THC-COOH) in oral fluid (OF) and urine was performed using homemade MISPEs for sample clean-up and liquid chromatography tandem mass spectrometry (LC-MS/MS). Cylindrical MISPE shaped pills were synthesized using catechin as a mimic template. MISPEs were added to 0.5 mL OF or urine sample and sonicated 30 min for adsorption of analytes. For desorption, the MISPE was transfered to a clean tube, and sonicated for 15 min with 2 mL acetone:acetonitrile (3:1, v/v). The elution solvent was evaporated and reconstituted in mobile, phase. Chromatographic separation was performed using a SunFire C18 (2.5 mu m; 2.1 x 20 mm) column, and formic acid 0.1 % and acetonitrile as mobile phase, with a total run time of 5 min. The method was fully validated including selectivity (no endogenous or exogenous interferences), linearity (1-500 ng/mL in OF, and 2.5-500 ng/mL in urine), limit of detection (0.75 and 1 ng/mL in OF and urine, respectively), imprecision (%CV