Abstract: Synthetic cathinones are a type of drugs belonging to group of 'new psychoactive substances' (NPSs). The illicit market of these substances is characterized by the continuous introduction in the market of new analogs to evade legislation and to avoid be detected. New screening and confirmation assays are therefore needed, mainly in forensic/clinical samples. In the current development a porous membrane protected - micro-solid-phase extraction (μ-SPE) has been developed for the assessment of several cathinones in urine. The μ-SPE devices consisted of a cone-shaped polypropylene (PP) porous membrane containing the adsorbent (molecularly imprinted polymers, MIPs, synthesized for the first time for this class of drugs). MIPs were prepared using ethylone and 3-methylmethcathinone (3-MMC) as templates, ethylene glycol dimethacrylate (EGDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, and 2,2'-azobisisobutyronitrile (AIBN) as initiator. The prepared ethylone-based MIP and 3-MMC-based MIP have been fully characterized and evaluated as new selective adsorbents for μ-SPE. Cathinones separation/determination was performed by high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). Optimum loading conditions (pH 5.0, loading for 4.0 min under orbital-horizontal shaking at 200 rpm) and elution conditions [2.0 mL of 75:20:5 heptane/2-propanol/ammonium hydroxide and ultrasounds assistance (37 kHz, 325 W) for 4.0 min] were found for ethylone-based MIP. Validation (intra-day and inter-day precision and analytical recovery) showed RSD values lower than 9 and 10% for intra-day and inter-day precision, and within the 88-101% range for intra-day and inter-day analytical recovery
Author keywords: synthetic cathinones, Molecularly imprinted polymer, porous membrane-protected micro-solid phase extraction, Urine, High performance liquid chromatography tandem mass spectrometry