Detection of Amphetamine Precursors with Quinoxaline-Bridged Cavitands

Selective uptake of the metamphetamine and amphetamine precursors safrole and benzyl methyl ketone (BMK) in air was obtained exploiting the molecular recognition properties of the quinoxaline-based cavitand (QxCav). The interactions responsible for the observed complexation were studied elucidating the molecular structures of the inclusion compounds with the analytes. Then, solid-phase microextraction (SPME) analyses were performed on fibers coated with QxCav to test the receptor prowess toward the drug precursors uptake from air. Both safrole and BMK, whose concentration in the vapor phase is in the low µg/m3 regime, are collected and pre-concentrated by the QxCav-SPME fiber, then thermally desorbed and identified via GC-MS.