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Due to the outbreak of COVID-19 pandemic, practicing personal hygiene such as frequent hand sanitising becomes a norm. The making of effective hand sanitiser products should follow the recommended formulations,...

A portable electrochemical device for xylazine detection is presented for the first time. An electrochemical paper-based analytical device (ePAD) was integrated with a smartphone. The fabrication of the ePAD involved wax printing, low-tack transfer tape, and cutting and screen-printing techniques. Graphene ink was coated on the substrate and modified with nanocoral-like polyaniline, providing an electron transfer medium with a larger effective surface area that promoted charge transfer. The conductive ink on the ePAD presented a thickness of 25.0 ± 0.9 μm for an effective surface area of 0.374 cm 2 . This sensor was then tested directly on xylazine using differential pulse voltammetry. Two linear responses were obtained: from 0.2 to 5 μg mL –1 and from 5 to 100 μg mL –1 . The detection limit was 0.06 μg mL –1 . Reproducibility was tested on 10 preparations. The relative standard deviation was less than 5%. The applicability of the sensor was evaluated with beverage samples spiked with trace xylazine. Recoveries ranged from 84 ± 4 to 105 ± 2%. The developed sensor demonstrated excellent accuracy in the detection of trace xylazine. It would be possible to develop the portable system to detect various illicit drugs to aid forensic investigations.

Presently, investigations of drug‐facilitated crimes (DFCs) rely on the detection of substances extracted from biological samples following intake by the victim. However, such detection requires rapid sampling and analysis prior to metabolism and elimination of the drugs from the body. In cases of suspected DFCs, drug‐spiked beverage samples, whether in liquid, droplet, or even dried form, can be tested for the presence of spike drugs and used as evidence for the occurrence of DFCs. This study aimed to quantitatively determine three sedative‐hypnotics (ketamine, nimetazepam, and xylazine) from drug‐spiked beverages using a vortex‐assisted dispersive liquid–liquid microextraction‐gas chromatography (VADLLME‐GC) approach. In this study, a GC method was first developed and validated, followed by the optimization of the VADLLME protocol, which was then applied to quantify the target substances in simulated forensic case scenarios. The developed GC method was selective, sensitive (limit of detection: 0.08 μg/ml [ketamine]; 0.16 μg/ml [nimetazepam]; 0.08 μg/ml [xylazine]), linear (R2 > 0.99), precise (%RSD <7.2%), and accurate (% recovery: 92.8%–103.5%). Higher recoveries were achieved for the three drugs from beverage samples in liquid form (51%–97%) as compared to droplet (48%–96%) and dried (44%–93%) residues. The recovery was not hindered by very low volumes of spiked beverage and dried residues. In conclusion, the developed VADLLME‐GC method successfully recovered ketamine, nimetazepam, and xylazine from spiked beverages that are likely to be encountered during forensic investigation of DFCs.

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Drugs-facilitated crimes (DFCs) involve the incapacitation of victims under the influence of drugs. Conventionally, a drug administration act is often determined through the examination of biological samples; however, dry residues from any surface, such as drinking glass if related to a DFC could be a potential source of evidence. This study was aimed to establish an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy coupled with chemometrics for the determination of spiked sedative-hypnotics from dry residues of a drug-spiked beverage. In this study, four sedative-hypnotics, namely diazepam, ketamine, nimetazepam, and xylazine were examined using ATR-FTIR spectroscopy. Subsequently, the ATR-FTIR profiles were compared and decomposed by principal component analysis (PCA) followed by linear discriminant analysis (LDA) for their detection and discrimination. Visual comparison of ATR-FTIR profiles revealed distinct spectra among the tested drugs. An initial unsupervised exploratory PCA model indicated the separation of four main sedativehypnotics clusters, and the proposed PCA score-LDA model had allowed for a 100% accurate classification. Discrimination of sedative-hypnotics from a dry beverage previously spiked with these drugs was also possible upon an additional extraction procedure. In conclusion, ATR-FTIR coupled with PCA score-LDA model was useful in detecting and discriminating sedative-hypnotics, including those that had been previously spiked into a beverage.

Xylazine is a sedative, analgesic and muscle relaxant widely applied in the veterinary field. However, owing to its depressant effect, xylazine has become a substance of abuse by humans. Misuse of xylazine not only triggers unwanted consequences (death), but also linked with various crimes. Google Scholar, PubMed and SciFinder were used to retrieve articles and case reports in relation to the misuses of xylazine and established analytical methods for forensic investigation until November 2021. Literatures reported the accidental and intended poisoning of xylazine, recreational use of xylazine and as an adulterant in recreational drugs. In addition to being a facilitator of crime and sexual assault, it is administered illegally to food producing animals as a sedative and to sports animals as a doping agent. Problems associated with the abuse of xylazine were highlighted in this review, covering the unknown prevalence of xylazine abuse and the need to revise the regulatory status of xylazine. In addition, limited screening and confirmatory methods that can be readily utilised to detect xylazine either alone or simultaneously with other substances of abuse, particularly useful for forensic toxicology and narcotic section were available in the literature. As a conventionally used veterinary drug, xylazine is undoubtedly a potentially hazardous drug, and the investigations on its potential abuse would enhance routine forensic examination to keep pace with the status of illicit drugs.