Heroin detection in a droplet hosted in a 3D printed support at the miniaturized electrified liquid-liquid interface.

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.

Capacitive sensing of an amphetamine drug precursor in aqueous samples: Application of novel molecularly imprinted polymers for benzyl methyl ketone detection.

Highly selective molecularly imprinted polymers (MIPs) towards benzyl methyl ketone (BMK) were synthesized for application as recognition elements in a capacitive sensor. A computational approach was employed to select the most appropriate monomers and cross-linkers. Using the selected compounds, different polymerization techniques and protocols were compared in order to study the effect on the MIP performance and characteristics. MIPs synthesized by bulk polymerization using itaconic acid and 1-vinylimidazole as monomers and p-divinylbenzene as cross-linker possess the highest affinity towards the target analyte. Prior to capacitive analysis, the developed particles were immobilized on the surface of gold transducers using tyramine as a linker. The validity of the developed sensor was checked by the BMK detection in spiked tap water and real water samples. A linear working range from 50 to 1000 µM was found while the limit of detection (LOD) was determined to be 1 µM in tap water. To the best of our knowledge, both the developed MIPs towards BMK and the electrochemical sensor for its detection have not been published or marketed to date.

Single-crystal X-ray diffraction analysis of designer drugs: hydrochlorides of metaphedrone and pentedrone.

This article, written as a result of cooperation between a police forensic laboratory and an academic institution, outlines the possibility of applying single-crystal X-ray diffraction analysis as an effective method of identifying designer drugs in forensic analysis. This technique allows crystalline samples to be determined with full assurance about their identity, even in the case of new substances for which no reference standards yet exist. Here, single-crystal X-ray diffraction measurements of single-crystal specimens obtained from two samples were performed. Solution and refinement of the structures demonstrated that the target compounds were metaphedrone and pentedrone hydrochlorides - synthetic cathinone derivatives used as recreational stimulants. In addition to the identification of the title compounds, this paper gives a first report on their crystal structures. Once the CIF-files containing the crystal structure data of the title compounds have been deposited in the Cambridge Structural Database - the world repository of small molecule crystal structures - it will be possible to identify single crystals of the title compounds quickly on the basis of simple parameters (lattice parameters a, b, c, α, ß, γ and unit cell volume). This description of the relationship between the geometrical parameters of moieties and the analysis of intermolecular interactions occurring in crystals of the title compounds extends knowledge about the synthetic derivatives of cathinone and may play a role in future studies, leading to a better understanding of their characteristic properties.

Side products of glycosidation with selected 2-acetamido-2-deoxy-D-glucopyranosides.

Allyl 2-acetamido-4,6-O-benzylidene-2-deoxy-3-O-formyl-alpha-D-glucopyranoside, N-acetyl-2,3,4-tri-O-acetyl-L-fucopyranosylamine and products of O-acetyl group migration were found as side products during glycosidation of selected 2-acetamido-2-deoxy-D-glucopyranosides.