The stability of cyanide in human biological samples. A systematic review, meta-analysis and determination of cyanide (GC-QqQ-MS/MS) in an authentic casework 7 years after fatal intoxication

A 30 year old man was found with no signs of life in front of the house. The cyanide concentration in blood and urine was determined five years after the man's death. What is more, a stability study was conducted for 730 days in an authentic casework blood sample. Sample preparation procedure included precipitation with methanol:water mixture, solid phase extraction (SPE) and derivatization with the use of PFB-Br (pentafluorobenzyl bromide). The sample was analyzed using GC-QqQ-MS/MS (gas chromatopraphy coupled with tandem mass spectrometry) isotope dilution method. Separation was done using a SH-RXI-5MS column (30 m x 0.25 mm, 0.25 µm). Detection of PFB-CN and PFB-13CN was achieved using a triple-quadrupole mass spectrometer with an electron ionization (EI) ion source in multiple reaction monitoring (MRM) mode. After 5 years from the man's death, cyanide concentration was: 1900 ng/mL in blood and 500 ng/mL in urine. Stability study performed in an authentic blood sample 6 and 7 years after the man's death revealed cyanide concentrations of 1898.2 ng/mL and 1618.7 ng/mL, respectively. While spectrophotometric and colorimetric methods recorded both decrease and increase in cyanide concentration over time, newer chromatographic methods mainly indicate a decrease. The studies presented in this paper seem to confirm this trend. However, in order to interpretate the results of cyanide concentration in biological material reliably, more research is still necessary.

Morphine (10, 20 mg) in a Postoperative Dressing Used with Patients After Surgical Debridement of Burn Wounds: A Prospective, Double-Blinded, Randomized Controlled Trial

Objective: This is the first clinical trial to evaluate the analgesic effect of 10 and 20 mg of morphine used in a postoperative dressing with patients after surgical debridement of burn wounds. Approach: In this randomized controlled trial, 20 adult patients with third-degree flame burns, who had undergone surgical debridement under general anesthesia, were randomly assigned to either group A, whose members were treated with a burn dressing that contained 10 mg of morphine, or group B, whose members were treated with a burn dressing that contained 20 mg of morphine; the dressing was also soaked with octenidine and phenoxyethanol in the case of both groups. The plasma morphine concentrations were measured 1, 2, 3, and 6 h after surgery, while the level of pain intensity was determined on the Numeric Pain Rating Scale (NRS), and the occurrence of side effects was observed. Results: The serum morphine concentration levels were very low, but statistically different between the two groups at all time points. The NRS value was similar in both groups at all time points (p > 0.05). Despite this, in group B, the NRS value was 0 in all patients in postoperative hours 1, 2, and 3. No adverse effect of morphine sulfate was observed in any patient. Innovation: This project is the first clinical study to have demonstrated that morphine administered in dressings in concentrations of 0.02-0.08 mg/mL significantly reduces the occurrence of pain. Conclusion: The use of morphine in dressings after surgical treatment of burn wounds is very effective when it comes to pain management and is safe for the patient.

The Arteries of the Encephalon Base in Caracal (Caracal caracal; Felidae; Carnivora)

This study represents the comprehensive anatomical analysis of the arterial circulation at the base of the encephalon in caracal (Caracal caracal), a member of the Felidae family. Caracals are found in various environments in Africa and Asia, and their conservation status is threatened by hunting and habitat loss. This study was conducted on 14 post-mortem specimens obtained from zoos. Three different methods were used to prepare the specimens-corrosive preparation, latex specimen preparation, and computer tomography imaging. This study revealed a configuration of the arterial circulation in the caracal encephalon resembling the shape of the number eight. The presence of the rostral communicating artery in this species is of particular significance, as it is associated with an increased ability to detect dehydration in the forebrain. This adaptation plays a crucial role in responding to challenges related to hydration. Comparative anatomical analysis with other felids highlighted differences in the shape and configuration of the encephalon's arterial circulation. This study also discussed the obliteration of the extracranial segment of the internal carotid artery in adult caracals, a feature shared with other Felidae members. The results of this study provide valuable information regarding the anatomy of blood vessels in caracals, with potential implications for veterinary practice in zoos and wildlife conservation efforts. This research expands our knowledge of this species' unique adaptations and physiological processes, contributing to the development of comparative anatomy in the Felidae family.

Nitrites: An Old Poison or a Current Hazard? Epidemiology of Intoxications Covering the Last 100 Years and Evaluation of Analytical Methods

In recent times, there has been a concerning and noteworthy rise in the global use of sodium nitrite for suicidal purposes. This is facilitated either through the employment of specialized "suicide kits" or by acquiring sodium nitrite through alternative means. Additionally, another occurrence contributing to nitrite poisoning is the recreational utilization of nitrites in the form of volatile aliphatic esters of nitrous acid, commonly referred to as "poppers". Based on current available papers and reports on the subject of nitrates, nitrites, and poppers intoxications, an epidemiological analysis and evaluation of analytical methods were performed. A total of 128 papers, documenting a collective count of 492 intoxication cases, were identified. Additionally, in order to complete the epidemiological profile of nitrite poisoning, the authors briefly examined six cases of nitrite intoxication that were under investigation in our laboratory. Furthermore, a review of nitrite poisoning cases over the past 100 years shows that the old poison is still in use and poses a substantial risk to society.

Determination of Prostaglandins (Carboprost, Cloprostenol, Dinoprost, Dinoprostone, Misoprostol, Sulprostone) by UHPLC-MS/MS in Toxicological Investigations

Prostaglandins have stimulative influence on the human uterus and therefore were introduced to medical treatment in reproductive healthcare as labor inductors or abortifacients. The UHPLC-ESI-QqQ-MS/MS method was developed for six prostaglandins: carboprost, cloprostenol, dinoprost (PGF2α), dinoprostone (PGE2), misoprostol and sulprostone (substances for pregnancy termination) in pharmaceutical samples and was applied for the toxicological examination of pills containing misoprostol (collected during gynecological examination). There were used two internal standards: misoprostol-d5 and PGF2α-d4. The quantification of analytes was performed in the MRM mode. The linearity of method was in the range from 0.1 to 10 µg/mL, with a coefficient of determination above 0.997 (R2) for each compound. The precision and accuracy values did not exceed ±5.0%. Analysis of the pills revealed the presence of two substances: misoprostol and diclofenac. Misoprostol and diclofenac dose per sample were as follows: 608.8 ng (sample 1), 708.4 ng (sample 2), 618.8 ng (sample 3) and 67.7 mg (sample 1), 65.3 mg (sample 2) 67.3 mg (sample 3), respectively. A simple, precise and reliable method can be applied for routine examinations in terms of clinical and forensic toxicology examinations as well as in quality control of drugs for pharmaceutical purposes (original drugs and counterfeit medications).

A narrative review of the neuropharmacology of synthetic cathinones-Popular alternatives to classical drugs of abuse

OBJECTIVE

To review the literature on the neuropharmacology of synthetic cathinones.

METHODS

A comprehensive literature search was carried out across multiple databases (mainly PubMed, World Wide Web, and Google Scholar) using relevant keywords.

RESULTS

Cathinones exhibit a broad toxicological profile, mimicking the effects of a wide variety of 'classic drugs' such as 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine and cocaine. Even small structural changes affect their interactions with key proteins. This article reviews existing knowledge of the mechanisms of action of cathinones at the molecular level, and key findings from research on their structure-activity relationship. The cathinones are also classified according to their chemical structure and neuropharmacological profiles.

CONCLUSIONS

Synthetic cathinones represent one of the most numerous and widespread groups among new psychoactive substances. Initially developed for therapeutic purposes, they quickly started to be used recreationally. With a rapidly increasing number of new agents entering the market, structure-activity relationship studies are valuable for assessing and predicting the addictive potential and toxicity of new and potential future substances. The neuropharmacological properties of synthetic cathinones are still not fully understood. A full elucidation of the role of some key proteins, including organic cation transporters, requires detailed studies.

Review of the experiences of users of methaqualone and methaqualone derivatives. An analysis of online forums

The aim of this review article was to collect and analyze the available information on methaqualone and its derivatives reported by users in dedicated online forums. Methaqualone is a sedative-hypnotic drug that has been widely used for medical purposes in the past, but is now illegal in most countries due to its high abuse potential. The review collected information on doses, routes of administration, desirable and side effects of intoxication and other relevant aspects of the abuse of these compounds. The results of the study suggest that methaqualone and its derivatives continue to be used by some individuals despite their illicit status and potential health risks. The review, in the absence of other more reliable toxicological data, provides valuable insights from direct users on the use of these substances.

A fatal case involving the highest ever reported 4-CMC concentration

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).

A review of synthetic cathinones emerging in recent years (2019-2022)

Purpose

The emergence of novel psychoactive substances (NPS) has been being a continuous and evolving problem for more than a decade. Every year, dozens of new, previously unknown drugs appear on the illegal market, posing a significant threat to the health and lives of their users. Synthetic cathinones are one of the most numerous and widespread groups among NPS. The purpose of this work was to identify and summarize available data on newly emerging cathinones in very recent years.

Methods

Various online databases such as PubMed, Google Scholar, but also databases of government agencies including those involved in early warning systems, were used in search of reports on the identification of newly emerging synthetic cathinones. In addition, threads on various forums created by users of these drugs were searched for reports on the effects of these new substances.

Results

We have identified 29 synthetic cathinones that have been detected for the first time from early 2019 to mid-2022. We described their structures, known intoxication symptoms, detected concentrations in biological material in poisoning cases, as well as the countries and dates of their first appearance. Due to the lack of studies on the properties of the novel compounds, we compared data on the pharmacological profiles of the better-known synthetic cathinones with available information on the newly emerged ones. Some of these new agents already posed a threat, as the first cases of poisonings, including fatal ones, have been reported.

Conclusions

Most of the newly developed synthetic cathinones can be seen as analogs and replacements for once-popular compounds that have been declining in popularity as a result of legislative efforts. Although it appears that some of the newly emerging cathinones are not widely used, they may become more popular in the future and could become a significant threat to health and life. Therefore, it is important to continue developing early warning systems and identifying new compounds so that their widespread can be prevented.

A Case of Amphetamine and Methamphetamine Intoxication in Cat

Stimulants belonging to the amphetamine group nowadays pose an undeniable worldwide threat to the life and health of users. Intoxications of domestic animals also occur, which can either be accidental or related to intentional human action. This study presents the first ever reported case of a simultaneous amphetamine and methamphetamine intoxication of a cat, along with the results of toxicological studies. Blood, urine, vitreous humor and liver were collected during the cat's autopsy and analyzed by UHPLC─QqQ─MS/MS. The sample preparation technique was based on one-step precipitation of proteins with cold acetonitrile. The determined amphetamine concentrations in the collected biological materials were 93.4 ng/mL in blood, 496.6 ng/mL in urine, 589.2 ng/mL in the vitreous humor and 291.2 ng/g in liver, respectively. Methamphetamine concentrations were 45.5 ng/mL in blood, 263.1 ng/mL in urine, 351.2 ng/mL in vitreous humor, and 97.7 ng/g in liver. Other substances were also found in the biological material, i.e., diazepam, oxazepam and nordiazepam. Cases of intentional or accidental poisoning of pets with psychoactive substances are a serious problem, carrying the risk to the health and life of the animal. Therefore, it is important to increase awareness of the high risk of poisoning of domestic animals, as well as to learn about the incompletely understood mechanisms of pharmacokinetics of various drugs in animals, including cats.

Simultaneous poisoning of 48 birds of prey – bendiocarb determination with the use of UHPLC-ESI-MS/MS method in fatal case from Eastern Europe

Aim: Bendiocarb is used against a wide range of insects but has already been withdrawn from the market in some countries. It poses a high risk to birds as they can accidentally ingest it while searching for food, followed by toxic effects. This paper presents the results of toxicological and histopathological studies of 48 cases of intentional birds of prey poisoning with bendiocarb in Eastern Europe, specifically Poland. Materials and methods: A novel ultra-high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry (UHPLC-ESI-MS/MS) method for bendiocarb determination in animal liver samples was developed and fully validated. The sample preparation technique was based on one-step precipitation of proteins with cold acetonitrile. The internal standard used was carbaryl-d7. Full time of analysis was less than 10 minutes. The application of the UHPLC-ESI-MS/MS method allowed us to achieve the lowest LOQ (1 ng/g) of bendiocarb in biological samples to date. Results: Necropsies and histopathological examinations of common ravens (Corvus corax), western marsh harriers (Circus aeruginosus), red kites (Milvus milvus), and a white-tailed eagle (Haliaeetus albicilla) revealed multi-organ toxicity manifested as congestion, oedema, or stagnation of blood. An analytical investigation confirmed the presence of bendiocarb in liver in the 1808–7721 ng/g range. Furthermore, the presence of this compound was qualitatively confirmed in the stomach and beak contents and also in the bait located near the deceased animals. Conclusions: A comprehensive forensic examination is crucial to monitor wildlife fatalities, especially applying a combined analytical and histopathological approach to identify and eliminate highly toxic substances which pose a threat to the ecosystem.

Determination of Mifepristone (RU-486) and Its Metabolites in Maternal Blood Sample after Pharmacological Abortion

The aim of the study was the development and validation of the UHPLC-QqQ-MS/MS method for the determination of mifepristone in human blood as well as the identification and quantification of its metabolites after self-induced pharmacological abortion. The metabolic pathway in humans was proposed after examination of an authentic casework. The fast and simple preanalytical procedure was successfully applied (pH9, tert-butyl-methyl ether). The validation parameters of the method were as follows: limit of quantification: 0.5 ng/mL; coefficients of determination: >0.999 (R2), intra- and inter-day accuracy and precision values did not exceed ± 13.2%. The recovery and matrix effect were in the range of 96.3−114.7% and from −3.0 to 14.7%, respectively. Toxicological analysis of the mother’s blood (collected the day after the pregnancy termination) revealed the presence of five compounds: mifepristone (557.4 ng/mL), N-desmethyl-mifepristone (638.7 ng/mL), 22-OH-mifepristone (176.9 ng/mL), N,N-didesmethyl-mifepristone (144.5 ng/mL) and N-desmethyl-hydroxy-mifepristone (qualitatively). To our knowledge, the study presented in this paper is the first report on the concentrations of mifepristone and its metabolites in maternal blood samples after performing a self-induced abortion. The established UHPLC-QqQ-MS/MS method is suitable for forensic toxicological analysis as well as in terms of clinical toxicology in future investigations (examination of pharmacokinetics, bioavailability and metabolism of RU-486).

Toxicological Aspects of Methotrexate Intoxication: Concentrations in Postmortem Biological Samples and Autopsy Findings

The aim of this study was the establishment of a UHPLC-QqQ-MS/MS method to determine methotrexate in postmortem biological samples and quantify the postmortem distribution of methotrexate in a case of fatal intoxication of this drug. A volume of 100 μL or 100 mg of postmortem specimens was precipitated with 400 μL of cold methanol and then analyzed using UHPLC-QqQ-MS/MS. The validation parameters of the method were as follows: limit of quantification: 0.1−1.0 ng/mL or ng/g, coefficient of determination: >0.998 (R2), matrix effect, intra- and inter-day accuracies and precisions: not greater than 13.6%, 14.8% and 17.4%, respectively. The recoveries were: 89.0−113.6%. The postmortem distribution studies revealed methotrexate concentrations as follows: blood—7.2 ng/mL, vitreous humor—0.8 ng/mL, liver—43.7 ng/g, kidney—20.6 ng/g, bone marrow—29.9 ng/g, lumbar vertebra—20.0 ng/g. The highest concentrations of methotrexate after poisoning were found in the tissues with the most rapidly dividing cells. The method described is simple, precise and selective. Methotrexate concentrations can be routinely determined in postmortem specimens. Determination of methotrexate in the postmortem biological material is possible after a few days of intensive treatment.

Diclofenac Concentrations in Post-Mortem Specimens-Distribution, Case Reports, and Validated Method (UHPLC-QqQ-MS/MS) for Its Determination

The aim of the research was to establish a sensitive method for the quantification of diclofenac in postmortem samples. The developed method was applied in six cases: three fetuses in which the use of abortion pills by their mothers was suspected, one case of duodenal ulcer perforation, one case of traffic accident with fatal outcome, and one acute renal failure in which the distribution of diclofenac was examined. The analyses were performed using liquid-liquid extraction of postmortem samples and the quantification of diclofenac via ultra-high performance liquid chromatography, coupled with triple quadrupole tandem mass spectrometry. Gradient elution using a C18 column was applied. Electrospray ionization measurement in positive multiple reaction monitoring mode was used. Diclofenac-d4 was used as an internal standard. The validation parameters were as follows: lower limit of quantification: 0.5 ng/mL, linearity of calibration curve: 0.5-500 ng/mL, intra- and interday accuracies and precisions: not greater than 15%; recovery values: 72.0-102.2%, and matrix effect: 2.2-28.0%. The developed method enabled the determination of diclofenac in human postmortem biological fluids (blood, urine, vitreous humor, bile, and stomach content), tissues (placenta, kidney, liver, and heart), and in exhumated fetus bones, with high recovery, sensitivity, precision, and accuracy.

The DI-SPME Method for Determination of Selected Narcotics and Their Metabolites, and Application to Bone Marrow and Whole Blood Analysis

The present investigation utilised the quick and easy SPME/LC-MS method to determine selected narcotic substances and their metabolites in whole blood. The study included qualitative analysis and validation of the method. Analytes were determined in the linearity range of 25−300 ng/mL. The precision during and between days (in general CV < 13.41%), and the LOD which results in between 0.36 and 11.08 ng/mL, and the LOQ between 1.20 and 36.90 ng/mL were investigated. The validation results obtained, as well as the results of subsequent in-laboratory tests, confirmed the applicability of the method in the analysis of blood samples. An attempt to apply the method to the analysis of bone marrow samples has yielded promising results; however, more detailed studies are needed in this area.

The dark side of social media: Two deaths related with chloroform intoxication

A suicide pact is an agreement between people to commit suicide together, which usually takes place at the same time, in the same place, by using the same method. Social media serve as a way of communication between people. Thus, they use such platforms to find potential suicide pact partners. Chloroform, although being regarded to as a slightly forgotten poison, is still linked to homicide and suicide cases. Death due to an acute chloroform ingestion may be a result of central nervous system depression. In this paper, we present application of headspace gas chromatographic method using a dual column/dual flame ionization detector (HS-GC-FID/FID) for the determination of chloroform in two fatal intoxication cases, as well as chloroform stability study. Analysis of biological samples revealed chloroform concentrations of 135.8, 16.1, 8.1, and 37.1 µg/ml in blood, urine, vitreous humor, and bile, respectively. Kidney, liver, and muscle specimens contained 119.5, 99.6, and 28.4 µg/g of chloroform, respectively. The results of stability studies indicate the highest decrease of chloroform in room temperature, so it is advised to store samples in a freezer. The addition of sodium fluoride is recommended as in blood samples collected to the test tubes without any preservative agent, the detection of chloroform after 91 days is almost impossible. It is important to emphasize that even old poisons can cause a lot of concerns today, as here described cases are linked to chloroform intoxication, as well as with possible danger which social media bring about nowadays.

Etazene induces developmental toxicity in vivo Danio rerio and in silico studies of new synthetic opioid derivative

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.

Severe poisoning after smoking a mixture of 4-fluoroisobutyryl fentanyl (4-FiBF) and alpha-pyrolidinoisohexaphenone (α-PiHP)

CONTEXT

Intoxications after ingestion of new psychoactive substances are currently one of the most challenging issues in clinical toxicology. Synthetic cathinones represented the largest group of drugs seized in 2020, but the increasing distribution of fentanyl analogues is resulting in a growing global opioid crisis. In addition, synthetic opioids may be intentionally combined with psychostimulants by drug manufacturers to reduce depressive effects. We report a case of severe poisoning after smoking a mixture of 4-fluoroisobutyryl fentanyl (4-FiBF) and alpha-pyrrolidinoisohexaphenone (α-PiHP).

CASE DETAILS

A 29-year-old male was found out of conscious in his apartment and taken to the Intensive Care Unit. Examinations revealed pinpoint pupils, slight respiratory acidosis, leukocytosis as well as body temperature of 39.4 °C and increased creatinine with decreased eGFR level. Toxicological analysis of biological samples revealed presence of 4-FiBF and α-PiHP in concentrations: 87.7 ng/mL and 5.0 ng/mL (blood) and 2291.0 ng/mL and 722.2 ng/mL (urine), respectively. After 4 days, the patient was discharged home.

DISCUSSION

Unique combination of clinical symptoms was a result of a simultaneous 4-FiBF and α-PiHP intoxication. To our knowledge, this is the first case of ingestion such unusual mixture of new psychoactive substances with a full description of medical treatment.

Photochemical transformation of fentanyl under the simulated solar radiation - Enhancement of the process by heterogeneous photocatalysis and in silico analysis of toxicity

In this study the photochemical transformation of fentanyl-a very potent opioid drug-under simulated solar radiation was investigated for the first time. This pharmaceutical is frequently detected in various environment samples at concentrations that should be regarded as potentially harmful. Nevertheless, to date, no drug phototransformation products (TPs) have been reported. Considering fentanyl's exceptionally high toxicity, knowledge of the properties of these potential TPs is essential in order to properly assess its pollution impact. In this study, all photolytic experiments were performed using a xenon lamp (D65 filter) and RP-UHPLC coupled with the ESI-high-resolution tandem mass spectrometry. The phototransformation of fentanyl in natural river water and the application of heterogeneous photocatalysis as a possible way of decontaminating water were also investigated. Fentanyl turned out to be photostable, but twenty-six previously unreported TPs (formed mainly as a consequence of hydroxylation and oxidation) were found and characterized. The applied catalysts-TiO₂ and ZnO-showed very high effectiveness, and the presence of the natural water matrix further increased the photodecomposition rate (up to 600 times) relative to direct photolysis. Importantly, the almost complete degradation of the parent compound as well as its TPs after 16 min of irradiation indicated that heterogeneous photocatalysis can be considered an efficient way of treatment of fentanyl-contaminated water. The computational analysis of toxicity showed that fentanyl may be more harmful to rodents and aquatic species than its TPs. However, some of these products are probably more mutagenic and developmentally toxic. Additionally, one product in particular may be a strong estrogenic compound, proving the importance of assessing TPs' toxic properties. The evaluation of bioaccumulation, bioconcentration and biodegradability revealed that fentanyl possesses unfavorable properties compared to TPs.

A novel procedure for stabilization of azide in biological samples and method for its determination (HS-GC-FID/FID)

Sodium azide is an old poison with toxicity comparable to potassium cyanide. It would seem to be completely forgotten however, between 2000 and 2020, the number of intentional ingestions and murders committed with sodium azide significantly increased. Furthermore, due to its extreme instability, sodium azide is difficult to detect, which poses an additional risk when used to commit a crime. In this study, the epidemiology of sodium azide exposures between 1920 and 2020 was investigated. For the determination the azide concentration in biological samples, a simple, precise and selective headspace gas chromatography method (HS-GC-FID/FID) was developed and fully validated. The limit of quantification was 0.65 µg/mL; and the limit of detection was 0.35 µg/mL; precision and accuracy did not exceed 20%. The stability study was conducted for various biological fluids (urine, bile, blood, gastric content) for 91 days in the refrigerator (4 °C) and the method for stabilization of azide was presented. The addition of a mixture of borax and sodium fluoride (w/w 3:1) to the test tubes can stabilize this poison. The described unique technique of collecting the biological samples poses a great potential for azide detection in clinical and toxicology laboratories even long time after human exposure to this substance.

Rapid Determination of Sufentanil in Human Plasma by UHPLC-QqQ-MS-MS

This paper presents a rapid, sensitive and precise method developed and validated for the quantification of sufentanil in biological samples using ultra-performance liquid chromatography coupled with QqQ-MS-MS. Plasma samples were extracted with simple and fast liquid-liquid extraction (ethyl acetate, pH 9). Calibration curve showed linearity in the concentration range of 0.005-30 µg/L. The lower limit of quantification was 0.010 µg/L. The most important method features are low lower limit of quantification value, simple plasma extraction and small sample volume. This method is suitable not only for evaluation of the pharmacokinetics, toxicology, bioavailability and clinical pharmacology of sufentanil but also for the detection and identification of this compound in human plasma samples for forensic purposes.

Detection of Drugs in Postmortem Specimens of Blood, Vitreous Humor and Bone Marrow Aspirate

In case of basic biological materials (blood, urine, vitreous humor) being unavailable, bone marrow can be used for toxicological tests. The aim of the study was to assess the concentration of various xenobiotics in the bone marrow, as well as in the blood and the vitreous humor. The analysis was performed in the biological material originating from the autopsy (n = 120), using the LC-MS method and with liquid/liquid extraction at pH = 9. As many as 46 different xenobiotics were detected in the biological material, strong correlations between the concentration of a given xenobiotic in blood and bone marrow, as well as in the vitreous humor and bone marrow, were noted for most of them, with the exception of diazepam and 7-aminoclonazepam. The obtained results indicate the possibility of using bone marrow to determine the concentration of numerous xenobiotics in the situation of basic biological materials being unavailable, as well as using the results obtained in the future to better understand the pharmacokinetic processes and the effect of postmortem redistribution on medication and drug concentrations in the body of a deceased person.

Old Poison, New Problem: Cyanide Fatal Intoxications Associated with Internet Shopping

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.

Acute intranasal intoxication with mercuric chloride taken accidently instead of cocaine - A case report

CONTEXT

Mercuric chloride (mercury (II) chloride) belongs to inorganic mercury compounds characterized by good water solubility and associated high toxicity. The paper describes an unusual case of intranasal intoxication with corrosive sublimate confused with cocaine by a young male.

CASE REPORT

Intranasal administration of corrosive sublimate caused severe local symptoms of chemical burn within the nasal cavity. From the 2nd day the patient developed symptoms of renal dysfunction with transient polyuria and serum retention of nitrogen metabolites. The patient was undergoing chelation therapy with DMPS, N-acetylcysteine and d-penicyllamine. Four procedures of haemodialysis were performed with simultaneous DMPS and N-acetylcysteine treatment. The urine mercury level on the first day of hospitalization was 1989 μg/L, and after 26 days of treatment returned to the physiological level. During treatment renal function was normalized, the patient was discharged in general good condition.

DISCUSSION

Mercuric chloride is readily absorbed from the nasal cavity. Its administration may cause intoxication manifested by both chemical burn at the exposure site and systemic symptoms, particularly renal impairment. Even in case of renal dysfunction the use of DMPS seems safe, if haemodialysis is performed at the same time. Simultaneous haemodialysis and chelation therapy may accelerate elimination of mercury from the organism.

Quantification of methadone and its metabolites: EDDP and EMDP determined in autopsy cases using LC-MS/MS

The paper presents a method for the determination of methadone, EDDP, and EMDP in postmortem biological materials using liquid-liquid extraction with ethyl acetate (pH9) and UHPLC-MS/MS technique. Methadone-d₉ and EDDP-d₃ were used as the internal standards. The method validation results for blood and urine were as follows: linearity: 0.5-1000 ng/ml; R²  > 0.9993 for methadone, EDDP and R²  > 0.9944 for EMDP. Intra- and inter-day precision: 0.1%-7.5% and 0.3%-8.6%, respectively; intra- and inter-day accuracy: -11.8% to 13.9% and -9.3 to 14.8%, respectively; recovery: 91.5%-123.0%; matrix effect: 83.5%-123.9%. This study also describes 18 postmortem cases, where methadone concentrations ranged 2.3-1180 ng/ml in blood (n = 17), from 11.0 to >10,000 ng/ml in urine (n = 13) and 135.2-409.0 in vitreous humor (VH, n = 3). EDDP concentrations ranged from not detectable to 180 ng/mL in blood, from 42.4 to >10,000 ng/ml in urine and 18.3-36.5 in VH. EMDP concentrations were found in four cases in blood from below LLOQ to 1.8 ng/ml and in seven cases in urine, ranged 2.1-243.0 ng/ml. EMDP was not detected in VH samples. The EDDP/methadone ratios and blood/urine ratios for methadone and EDDP in EMDP-positive and negative cases were performed. The paper presents mass spectra of other methadone metabolites, than EDDP and EMDP (ring hydroxylated methadone, ring hydroxylated EDDP, ring hydroxylated EMDP, methadol, and DDP). Simultaneous determination of methadone and its metabolites in order to unequivocally interpret the results of toxicological tests seems to be useful in cases related to prescription/illicit use of methadone.

Fatal intoxication with U-47700 in combination with other NPS (N-ethylhexedrone, adinazolam, 4-CIC, 4-CMC) confirmed by identification and quantification in autopsy specimens and evidences

Purpose

We present a case of fatal intoxication with U-47700 in combination with other NPS (N-ethylhexedrone, adinazolam, 4-chloro-N-isopropylcathinone (4-CIC), 4-chloromethcathinone (4-CMC) and sertraline) confirmed by identification and quantification in biological materials and evidences found at the scene in 2017 in Poland.

Methods

Blood and urine samples were extracted with ethyl acetate from alkaline medium (pH 9); powders/crystals were diluted with methanol. The analysis was carried out using ultra-high-performance liquid chromatography–tandem mass spectrometry. Validation criteria were evaluated for blood and urine at the concentrations of 10 and 100 ng/mL.

Results

The validation parameters of the method were within acceptable ranges. In the presented case, the determined concentrations of drugs were as follows, in blood: U-47700, 1470 ng/mL; N-ethylhexedrone, 58 ng/mL; adinazolam, 18 ng/mL; 4-CIC, 8.0 ng/mL; 4-CMC, 1.7 ng/mL; in urine: U-47700, 3940 ng/mL; N-ethylhexedrone, 147 ng/mL; adinazolam, 82 ng/mL; 4-CIC, 130 ng/mL; 4-CMC, 417 ng/mL. Sertraline (blood, 89 ng/mL; urine, 32 ng/mL) was also determined in both materials. The same substances were also found in 5 powders/crystals: U-47700 (12% by weight), N-ethylhexedrone (54%), adinazolam (14%), 4-CIC (23%), 4-CMC (26%). After 775 days of storage, biological samples at + 4 °C, the most stable substance was sertraline and the less, synthetic cathinones, especially 4-CIC and 4-CMC.

Conclusions

The described case of fatal intoxication with NPS presented postmortem concentrations of U-47700, 4-CMC, N-ethylhexedrone, adinazolam and 4-CIC for the first time in the literature. The paper also showed stability study of these substances stored at + 4 °C for 775 days.

The application of headspace gas chromatographic method for the determination of ethyl alcohol in craft beers, wines and soft drinks

The increasing interest of consumers in the still-developing craft beer market and the strict tax-related legal regulations concerning alcoholic beverages require precise methods for quality control. Determination of ethyl alcohol concentration was performed in 167 samples of alcoholic beverages (craft beers, soft drinks, wines, and cider). We applied headspace gas chromatography using a dual column/dual flame ionization detector (HS-GC-FID/FID), a technique routinely used in forensic toxicology. The method was linear in range, from 0.01 to 20.0%, with a coefficient of determination of 0.999 (R2). The limit of quantification was 0.01%; the detection limit was 0.003%. Furthermore, very good validation parameters were achieved (precision and accuracy below 5%). The samples were analyzed for compliance with EU standards and recommendations of The Beer Judge Certification Program. Moreover, the content of trace quantities of volatile compounds and fusel alcohols (1-propanol, 2-propanol, acetone, and acetaldehyde) was found in the majority of alcoholic beverages.

A novel simple and precise method for the determination of azide impurity in sartans using headspace gas chromatography with two dissimilar capillary columns and two flame ionization detectors (HS-GC-FID/FID)

Determination of azide as an impurity in medicinal products was performed for the following sartans with tetrazole functional group (synthesized with the use of azide ion): candesartan, losartan, irbesartan, olmesartan medoxomil, and valsartan. This was achieved using headspace gas chromatography using a dual column/dual flame ionization detector (HS-GC-FID/FID). The method was linear in range, from 5.0-30.0 μg/g, with a coefficient of determination of >0.998 (R²). The limit of quantification was 5.0 μg/g and the detection limit was 1.9 μg/g. The sample preparation procedure is fast and simple. The validation procedure was performed in accordance with International Conference on Harmonization (ICH) and Pharmacopeia guidelines. Moreover, besides the content of azide ions, trace quantities of residual solvents (methanol, ethanol, acetone, isopropanol) were found in the majority of sartan tablets.

THU0186 CLINICAL EVALUATION OF THE IMMUNOGENICITY TO CT-P13 FOR SUBCUTANEOUS USE IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS: 1-YEAR CLINICAL RESULTS FROM A MULTICENTER, RANDOMIZED CONTROLLED PIVOTAL TRIAL

Background:

Novel subcutaneous infliximab (CT-P13 SC) was developed to augment the flexibility in therapeutic use of infliximab and noninferiority (NI) of CT-P13 SC versus CT-P13 intravenous (IV) was demonstrated for efficacy in patients with rheumatoid arthritis (RA) [1]. CT-P13 SC 120mg biweekly showed consistent higher therapeutic trough levels during the treatment period, which helps in maintaining efficacy over time. Since immunogenicity has clinical importance in patients using anti-TNF alpha agents and there is a general presumption that SC route is more immunogenic than IV route, this needs careful assessment.

Objectives:

Immunogenicity assessment of CT-P13 SC with further impact analysis has been performed on the pivotal data set [1] to determine whether there was any correlation between the magnitude of anti-drug antibody (ADA) positivity and clinical outcomes in RA patients.

Methods:

The immune response against CT-P13 in human serum was detected using an electrochemiluminescence (ECL) platform with an Affinity Capture Elution (ACE) step. An ADA ECL ACE assay showed ability to detect ADA at low levels in all samples regardless of residual drug in serum (25 ng/mL ADA in the presence of 80 μg/mL of CT-P13 in RA serum). To investigate the impact of ADA titer on PK, efficacy and safety, key clinical parameters were assessed by visit based ADA titer quartile. All patients who had ‘Positive’ ADA status result at each visit were included in the analysis and categorized into 4 groups using the 25th, 50th, 75th percentiles of ADA titer result, respectively.

Results:

The four subgroups categorized by quartiles at each visit from week 22 to week 54 were: 1st (ADA titer ≤ 3), 2nd (3 < ADA titer ≤ 9), 3rd (9 < ADA titer ≤ 27) and 4th (27 < ADA titer). There was a trend for pre-dose concentration to decrease as ADA titer increases for both CT-P13 SC and CT-P13 IV arms as expected (Figure 1). Patients in the 1st and 2nd subgroup maintained the sufficient therapeutic drug concentration level. Figure 2 shows the correlation between ADA titer and efficacy outcomes where the change from baseline of DAS28 (CRP) and the proportion of patients achieving ACR20 were lower in the 3rd and 4th subgroups. The ADA impact was especially apparent in the 4th subgroup where the mean pre-dose concentration of the patients was below the therapeutic drug concentration level (1 μg/mL), which led to worse efficacy outcomes in both arms, IV as well as SC. Nevertheless, no impact of ADA on safety profile in both arms was observed. A neutralizing antibody (NAb) method with enhanced drug tolerance but limited performance was also developed and clinical consequences of NAb titer in terms of PK, efficacy and safety were not different from the results with ADA.

Conclusion:

The analysis of both ADA positivity and titer is clinically meaningful in the prediction of PK profile and clinical response. CT-P13 SC administration did not result in a greater incidence of ADA compared to the CT-P13 IV and there were no clinical differences depending on the formulation.

References:

[1]Westhovens R, et al. Annals of the Rheumatic Diseases 2019;78:1158-1159.

Disclosure of Interests:

Rene Westhovens Grant/research support from: Celltrion Inc, Galapagos, Gilead, Consultant of: Celltrion Inc, Galapagos, Gilead, Speakers bureau: Celltrion Inc, Galapagos, Gilead, DaeHyun Yoo Grant/research support from: Celltrion, Inc, Consultant of: Celltrion, Inc, Speakers bureau: Celltrion Healthcare, Inc, Piotr Wiland Grant/research support from: Celltrion, Inc, Speakers bureau: Novartis, Pfizer, Abbvie, Gedeon-Richter, Lilly, Roche, Sandoz, Marek Zawadzki Grant/research support from: Celltrion, Inc, Delina Ivanova Grant/research support from: Celltrion, Inc, Alfredo Berrocal Grant/research support from: Celltrion, Inc, Speakers bureau: Pfizer, Elias Chalouhi Grant/research support from: Celltrion, Inc, Éva Balázs Grant/research support from: Celltrion, Inc, Consultant of: Amgen, Sergii Shevchuk Grant/research support from: Celltrion, Inc, Sang Joon Lee Shareholder of: Celltrion, Inc, Employee of: Celltrion, Inc, Sung Hyun Kim Shareholder of: Celltrion, Inc, Employee of: Celltrion, Inc, JeeHye Suh Employee of: Celltrion, Inc, Chankyoung Hwang Employee of: Celltrion, Inc, Dae Seok Choi Shareholder of: Celltrion, Inc, Employee of: Celltrion, Inc

The Stability of 4-Chloromethcathinone in Blood and Vitreous Humor

We present results of our study on the stability of 4-chloromethcathinone (4-CMC) in authentic postmortem peripheral blood and vitreous humor samples. The stability of 4-CMC was determined in postmortem blood samples (for a period of 90 days) and vitreous humor (30 days) at three different temperatures: -15°C, +4°C, and + 23°C. The analyses were carried out using ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). In both materials, the lowest 4-CMC stability was demonstrated at room temperature. The blood samples stored in a freezer (-15°C) showed stability for the entire study period (90 days), while in the case of the vitreous humor sample stored at the same temperature the concentration of the substance decreased by 53% after 30 days. The study carried out in authentic postmortem blood and vitreous humor samples confirms the previous reports of 4-CMC instability in biological material. Authors suggest that the biological material should be stored frozen until analyses are carried out as soon as possible after collection of the material.

Dissociative electron attachment to benzoic acid (C7H6O2)

The dissociative electron attachment (DEA) to benzoic acid (C₆H₅COOH) has been studied using an experimental crossed beam setup of a quadrupole mass spectrometer and a trochoidal electron monochromator. Relative partial cross sections for the DEA to produce negative ion fragments show the main channels for dissociation. The comparison of the present results with the ultraviolet photoelectron spectrum of benzoic acid [J. Meeks, A. Wahlborg, and S. P. McGlynn, J. Electron Spectrosc. Relat. Phenom. 22, 43 (1981)] implies that most DEA bands in the high energy range are due to Feshbach resonances with double occupation of diffuse Rydberg-like orbitals. The measurements are supported by density functional theory calculations of the threshold energies.

Dissociative ionization dynamics of dielectric gas C3F7CN

Fluoronitrile C₃F₇CN is a promising candidate for the replacement of SF₆ dielectric gas in high-voltage insulation.

Electron attachment to hexafluoropropylene oxide (HFPO)

We probe the electron attachment in hexafluoropropylene oxide (HFPO), C₃F₆O, a gas widely used in plasma technologies. We determine the absolute electron attachment cross section using two completely different experimental approaches: (i) a crossed-beam experiment at single collision conditions (local pressures of 5 × 10^-4 mbar) and (ii) a pulsed Townsend experiment at pressures of 20-100 mbar. In the latter method, the cross sections are unfolded from the electron attachment rate coefficients. The cross sections derived independently by the two methods are in very good agreement. We additionally discuss the dissociative electron attachment fragmentation patterns and their role in the radical production in industrial HFPO plasmas.

Resonances and Dissociative Electron Attachment in HNCO

In a combined experimental and theoretical study, we probe the dissociative electron attachment in isocyanic acid HNCO. The experimental absolute cross section for the NCO^{-} fragment shows a sharp onset and fine structures near the threshold. The autoionizing state responsible for the dissociative attachment is found in both the R-matrix calculation and using analytic continuation in the coupling constant. The involved A^{'} resonance has a mixed π^{*}/σ^{*} character along the dissociating bond and thus combines the effects of nonzero electron angular momentum and dipole-supported states. This leads to unusual behavior of its width at various geometries. Because the potential energy gradient of the autoionizing state points essentially in the direction of the N─H bond, nuclear dynamics can be described by a one-dimensional nonlocal model. The results agree with the experiment both quantitatively and qualitatively. The present system may be a prototype for interpretation of the dissociative electron attachment process in a number of other polyatomic systems.

Low energy differential elastic electron scattering from acetonitrile (CH3CN)

Measurements of elastic differential cross sections for electron scattering from acetonitrile (CH₃CN) have been performed utilizing a crossed electron-molecular beam experiment and with the relative flow method, for the incident electron energy range of 0.7 eV-30 eV and the scattering angle range of 10°-130°. These differential cross sections have been used to calculate the elastic integral and momentum-transfer cross sections, revealing a π ^* resonance located around 3 eV. The elastic differential cross sections are compared with available theoretical models using the R-matrix method and the Schwinger multichannel method.

Marijuana intoxication in a cat

Background

Cannabis from hemp (Cannabis sativa and C. indica) is one of the most common illegal drugs used by drug abusers. Indian cannabis contains around 70 alkaloids, and delta-9-tetrahydrocannabinol (delta-9-THC) is the most psychoactive substance. Animal intoxications occur rarely and are mostly accidental. According to the US Animal Poison Control Center, cannabis intoxication mostly affects dogs (96%). The most common cause of such intoxication is unintentional ingestion of a cannabis product, but it may also occur after the exposure to marijuana smoke.

Case presentation

A 6-year-old Persian cat was brought to the veterinary clinic due to strong psychomotor agitation turning into aggression. During hospitalisation for 14 days, the cat behaved normally and had no further attacks of unwanted behaviour. It was returned to its home but shortly after it developed neurological signs again and was re-hospitalised. On presentation, the patient showed no neurological abnormalities except for symmetric mydriasis and scleral congestion. During the examination, the behaviour of the cat changed dramatically. It developed alternate states of agitation and apathy, each lasting several minutes. On interview it turned out that the cat had been exposed to marijuana smoke. Blood toxicology tests by gas chromatography tandem mass spectrometry revealed the presence of delta-9-tetrahydrocannabinol (THC) at 5.5 ng/mL, 11-hydroxy-delta-9-THC at 1.2 ng/mL, and 11-carboxy-delta-9-THC at 13.8 ng/mL. The cat was given an isotonic solution of NaCl 2.5 and 2.5% glucose at a dose of 40 mL/kg/day parenterally and was hospitalised. After complete recovery, the cat was returned to it’s owner and future isolation of the animal from marijuana smoke was advised.

Conclusions

This is the first case of a delta-9-tetrahydrocannabinol intoxication in a cat with both description of the clinical findings and the blood concentration of delta-9-THC and its main metabolites.

Fentanyl and its derivatives as a group of new psychoactive substances (designer drugs)

Fentanyl has been known for many years. It has been widely used in emergency medicine and anaesthesiology. Due to its strong action, it gained a reputation of a popular addictive drug. Over the past years, fentanyl derivatives, produced as new psychoactive substances (designer drugs), have become a growing problem in clinical and forensic toxicology due to their non-therapeutic use. Both the variability in the construction of fentanyls and, consequently, the change in toxokinetic properties, as well as their high toxicity, often lead people to take this group of compounds to fatal intoxication. The purpose of this paper is to present various formulations of fentanyl and to discuss the properties of fentanyl and its derivatives, with particular emphasis on the toxicity of this group of compounds. Reviewing the available literature, the authors also focused on presenting the therapeutic concentrations of fentanyl and its most popular analogues, comparing them with the concentrations observed in lethal opioid poisonings.

The detection of capsaicin and dihydrocapsaicin in horse serum following long-term local administration

Background

Capsaicin and dihydrocapsaicin are alkaloids with analgesic effects in humans and animals. When used locally, both of them minimalise pain sensation by defunctionalising nerve endings. According to the Federation Equestrian International Prohibited Substances List, these are substance banned in horse competitions. The aim of the study was to determine the detection time of capsaicin in both plasma and serum after long-term use of a gel recommended for commercial use and applied as intended. The objective of the study was to select the best material for the detection of capsaicin as a doping substance in horses.

Methods

Nine healthy mature horses were administered 0.1% capsaicin topically in the form of a commercial analgesic gel (15 g of the gel per limb) to the front limbs every 24 hours for five days with a polar fleece bandage. Blood serum and plasma were collected prior to gel application and in the 12th, 18th, 24th, 36th, 42nd, 48th, 60th, 84th, 108th, 132nd, 156th hour after the gel application. Qualitative and quantitative analysis was performed using ultra-high performance liquid chromatography coupled with a triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS).

Results

The concentration of capsaicin in the serum samples did not exceed the lower limit of quantification. Capsaicin was not detected in the plasma samples during the entire study period. Dihydrocapsaicin was not detected in blood serum or plasma.

Conclusion

The presented results suggest that capsaicin is not detected in horse serum in the 24-hour-periodfollowing its last application according to the dosage regimen used by owners and veterinarians for therapy rather than doping, based on a five day gel application and a polar bandage.

Dissociative electron attachment and anion-induced dimerization in pyruvic acid

We report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions. We ascribe their production to secondary reactions of the transient anions with neutral molecules. Such reactions turn out to be unusually efficient; the most probable reason for this is that they proceed via the formation of a double-hydrogen-bonded complex followed by an ultrafast proton transfer between the reaction partners.