APPLICATION OF ULTRASOUND-ASSISTED LIQUID-LIQUID MICRO EXTRACTION COUPLED WITH GAS CHROMATOGRAPHY-MASS SPECTROMETRY FOR THE RAPID DETERMINATION OF SYNTHETIC CANNABINOIDS AND METABOLITES IN BIOLOGICAL SAMPLES.

The constant emergence of New Psychoactive Substances is a challenge to clinical and forensic toxicologists that need to constantly update analytical techniques to detecting them. A large portion of these substances are synthetic cannabinoids. The aim of this study was to develop a rapid and simple method for the determination of synthetic cannabinoids and their metabolites in urine and blood using GC-MS. The method involves an Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction which implies a rapid procedure, giving excellent extraction efficiencies with minimal use of toxic solvents. This is followed by silylation and analysis with GC-MS. The chromatographic method allows for the separation and identification of 29 selected synthetic cannabinoids and some metabolites. The method was validated on urine and blood samples with the ability to detect and quantify all analytes with satisfactory limits of detection (from 1 to 5 ng/mL), limits of quantification (5 ng/mL), selectivity and linearity (in the range 5 - 200 ng/mL). The developed assay is highly applicable to laboratories with limited instrumental availability, thanks to the use of efficient and low-cost sample preparation and instrumental equipment. The latter may contribute to enhance the detection of NPS in clinical and forensic toxicology laboratories.