In this work, we have focused on the profiling of 5647 street samples covering marijuana, common and new recreational illicit drugs. All samples were analyzed using gas chromatography-mass spectrometry (GC-MS) technique. In total we have identified 53 illicit drugs with Δ-9-tetrahydrocannabinol (THC), amphetamine, N-ethylhexedrone, 3,4-methylenedioxy methamphetamine (MDMA), 4-chloromethcathinone (4-CMC), α-pyrrolidinoisohexaphenone (α-PHiP), cocaine, and 4-chloroethcathinone (4-CEC) being most commonly found and making 38.5, 17.8, 15.5, 8.0, 3.5, 2.7, 2.1, and 2.0% of the total studied pool, respectively. Except for methadone, all analyzed street samples were spiked with at least one cutting agent. Caffeine was the most frequently found adulterating addition present in around 33% (excluding marijuana) of the analyzed samples. Other identified cutting agents make an impressive group of more than 160 compounds. Finally, we have tabulated, illustrated, and discussed presented data in a view of smart and portable sensors development.
In this work, the use of square-wave adsorptive stripping voltammetry (SWAdSV) in combination with boron-doped diamond electrode modified with multiwalled carbon nanotubes (MWCNTs-BDDE) and β-cyclodextrin (β-CD, β-CD-MWCNTs-BDDE) for the determination of the fungicide carbendazim (Cbz) is described for the first time. Cbz oxidation response was observed in the Britton-Robinson buffer supporting electrolyte in a pH range from 2.3 to 6.0 in potential range from + 1.0 to + 1.3 V vs SCE. The SWAdSV peak current of Cbz oxidation response on β-CD-MWCNTs-BDDE with peak maxima close to + 1.2 V vs SCE at pH 4.0 was linear over the wide linear dynamic range of 6.72 × 10−7–1.12 × 10−5 mol L−1 with a detection limit (LOD) of 1.96 × 10−7 mol L−1. The obtained results demonstrated the viability of the proposed methodology for determination of Cbz in river water samples containing low concentrations of Cbz. Moreover, the effect of Cbz on the corrosion properties of an AISI type 316 L stainless steel used to fabricate farming equipment and tools was tested by means of the potentiodynamic method. The characterization and evaluation of the corrosion inhibition effect raised from the use of Cbz was performed using optical microscope.
1 October 2018 in Journal of Electroanalytical Chemistry
Simple sensing protocols for the detection of illicit drugs are needed. Electrochemical sensing is especially attractive in this respect, as its cost together with the analytical accuracy aspires to replace still frequently used colorimetric tests. In this work, we have shown that the interfacial transfer of protonated heroin can be followed at the electrified water-1,2-dichloroethane interface. We have comprehensively studied the interfacial behavior of heroin alone and in the presence of its major and abundant cutting agents, caffeine and paracetamol. To maximally increase developed sensing protocol applicability we have designed and 3D printed a platform requiring only a few microliters of the aqueous and the organic phase. The proposed sensing platform was equipped with a cavity hosting a short section of Ag/AgCl electrode, up to 20 µL of the aqueous phase and the end of the micropipette tip being used as a casing of a fused silica capillary having 25 µm as the internal pore diameter. The volume of the organic phase was equal to around 5 µL and was present inside the micropipette tip. We have shown that under optimized conditions heroin can be detected in the presence of caffeine and paracetamol existing in a sample with 10,000 times excess over the analyte of interest. The calculated limit of detection equal to 1.3 µM, linear dynamic range spanning to at least 50 µM, good reproducibility, and very low volume of needed sample is fully in line with forensic demands.