In this work we applied a recently developed ionic liquid assisted in-situ solvent formation microextraction coupled with magnetic nano-particle based dispersive micro-solid phase extraction following by HPLC diode array detector (IL-ISFME/D-µ-SPE/HPLC-DAD) for preconcentration and measurment of cannabinoid compounds (THC-9, CBN, CBD) in urine samples. The extraction involved a primary extraction based on IL-ISFME technique followed by a D-µ-SPE step. In the final, the extracted analytes introduced to HPLC-DAD by means of methanol. The condition of the technique were optimized regarding to six effective factors including IL amount, ion pairing salt amount, magnetic nano-particle amount, organic solvent volume, ionic strength and organic solvent type. The whole optimization procedure was done within 159 experimental runs. Optimization procedure was performed by a full factorial central composite design (CCD). This new technique provided up to 98-113 fold preconcentration of the analytes under the optimized conditions. Good repeatabilities (with RSDs 1.8-2.1%) were obtained. Detection limits were in the range of 0.2–1.4 ng/ml.
Keywords: cannabinoids, THC-9, CBN, CBD, ISFME, D-µ-SPE