Purpose The aim of the study was to present the spectroscopic characteristics and crystal structure of the etazene—a benzimidazole opioid, which appeared on the illegal drug market in Poland in the last weeks. Methods The title compound was analyzed by X-ray crystallography as well as gas and liquid chromatography combined with mass spectrometry. Spectroscopic techniques have also been used, such as nuclear magnetic resonance, infrared and ultraviolet-visible spectroscopies. Results We presented the identification and the broad chemical characterization of etazene, a synthetic opioid that has recently been introduced on the illegal drug market. Conclusions In this paper, we described single-crystal X-ray, chromatographic and spectroscopic characterization of a synthetic opioid that emerged on the new psychoactive substance (NPS) market in Poland. To the best of our knowledge, this is the first full characterization of etazene. Analytical data presented in the work can be helpful in identification and detection of the NPS in forensic and clinical laboratories.

Synthetic cathinones comprise a large amount of substances present on the dark market, which creates an undeniably worldwide problem and still is posing a threat. A 22‐year‐old man was brought to the Emergency Room from a party, where he had ingested orally 20 g of mephedrone. The man exhibited a disorder of consciousness with no logical verbal contact and dilated pupils. Moreover, a metabolic acidosis was present. The patient died after an hour from an admission to the ER. Blood and vitreous humor collected during an autopsy were analyzed with the use of an ultra‐high‐performance liquid chromatography‐tandem mass spectrometry (UHPLC‐QqQ‐MS/MS) with the use of C18 column in multiple reaction monitoring (MRM) mode. Both biological specimens were prepared using liquid–liquid extraction (LLE) with the use of ethyl acetate and 0.5 M ammonium carbonate water solution (pH 9). The limit of quantification (LOQ) of the method was 0.5 ng/ml in both matrices; precision and accuracy values did not exceed ±15%. Recovery of the method was in the range of 86.1%–102.7%. Determined concentrations of 4‐CMC were 8542 and 9874 ng/ml in blood and vitreous humor, respectively. Other substances present in both biological materials were: atropine, diazepam, lidocaine, and its metabolite norlidocaine, as well as methcathinone and ethyl alcohol. The concentration presented in here described case is the highest ever reported 4‐CMC concentration. Important aspect is also receiving other NPS by recreational users than intended, which lead to accidental poisoning (in presented case user assumed 4‐CMC was 4‐MMC).

Purpose Development of ultra-high-performance liquid chromatography-triple quadrupole tandem mass spectrometry method for quantification of 4-fluoroisobutyryl fentanyl (4-FiBF) and its distribution in postmortem biological samples in four fatal intoxication cases, which occurred in September 2018, in Poland. Methods Biological fluids (blood, urine, vitreous humor, bile, gastric content) and tissues (brain, kidney, liver, stomach wall) were extracted with ethyl acetate from alkaline medium (pH 9). Fentanyl-d5 was used as internal standard. Results The validation parameters were as follows: lower limit of quantification: 0.1 ng/mL (biological fluids) and 0.1 ng/g (solid tissues), intra- and inter-day accuracies and precisions: not greater than 20%; recovery values: 86.9–110%; matrix effect: − 13.1–10.4%. Among all tested biological fluid, the highest concentration of 4-FiBF was found in bile (average concentration of 3390 ng/mL) while among the tissues, in liver (average concentration of 1650 ng/g). Furthermore, in collected specimens, there were also found other drugs and new psychoactive substances (NPS) e.g. N-ethylpentylon, 4-chloromethcathinone (4-CMC) and α-pyrrolidinoisohexanophenone (α-PiHP). Concentrations and distributions of these substances in postmortem samples have been also detailed. Examinations of seized drug (in case 4) revealed that it included the mix of 4-FiBF and α-PiHP. Conclusions The developed and fully validated method enabled for determination of 4-FiBF in postmortem biological fluids and tissues. To our knowledge, this is the first report of distribution study of 4-FiBF with other NPS (N-ethylpentylon, 4-CMC and α-PiHP) in authentic fatal intoxication cases.

Widespread access to the Internet has an increasing influence on how suicides are committed. On websites such as eBay® or Amazon.com® highly toxic substances including cyanides are available for purchase. In the last 5 years, a few fatal intoxications associated with Internet shopping and buying “suicide kits” have been reported. Epidemiology of intoxications reported by American Association of Poison Control Centers between 2000-2018 shows that about 10% of all exposures to cyanide were related to suicide attempts and intentional ingestion of this substance. In order to determine the cyanide concentration in four fatal intoxication cases associated with Internet shopping, a headspace gas chromatography with dual column/dual flame ionization detector (HS-GC-FID/FID) method was validated and applied to casework. The method was linear in range, from 1 to 50 µg/mL, with a coefficient of determination of 0.999 (R2). The limit of quantification was 1.0 µg/mL; the detection limit was 0.5 µg/mL. Intra- and inter-day validation precision and accuracy did not exceed 10% and 15%, respectively. Recovery and matrix effect values ranged from 94.8– 103.8% and -5.2─3.8%, respectively. The cyanide concentrations were determined in biological fluids (blood, urine, bile, vitreous humor, gastric content) and postmortem tissue samples (spleen, kidney, liver, brain). The headspace gas chromatographic method, which is routinely used in clinical and forensic toxicology to quantify ethanol with its congeners (methanol, acetone, isopropanol, n-propanol and n-butanol), can be also applied to determine cyanide in intoxication cases. The global problem of a high number of suicides each year, requires increasing and more restrictive control of highly toxic substances available online as well as caution monitoring of human exposure to cyanide. This old and well known poison is being increasingly used nowadays for suicidal purposes, therefore determination of cyanide in biological samples is still important in terms of clinical and forensic toxicology.

Synthetic opioids are gaining more and more popularity among recreational users as well as regular abusers. One of such novel psychoactive substance, is etazene, which is the most popular opioid drug in the darknet market nowadays. Due to limited information available concerning its activity, we aimed to characterize its developmental toxicity, including cardiotoxicity with the use of in vivo Danio rerio and in silico tools. Moreover, we aimed, for the first time, to characterize the metabolite of etazene, which could become a potential marker of its use for future forensic analysis. The results of our study proved severe dose-dependent developmental toxicity of etazene (applied concentrations 10–300 µM), including an increase in mortality, developmental malformations, and serious cardiotoxic effects, as compared with well-known and used opioid—morphine (applied concentrations 1–50 mM). In silico findings indicate the high toxic potential of etazene which may lead to drug-drug interactions and accumulation of substances. Furthermore, phase I metabolite of etazene resulting from N-dealkylation reaction was identified, and therefore it should be considered as a target for toxicological screening. Nonetheless, the exact mechanism of observed effects in response to etazene should be further examined.