Development of an LC-MS/MS method for the determination of five psychoactive drugs in postmortem urine by optimization of enzymatic hydrolysis of glucuronide conjugates

PURPOSE

Toxicological analyses of biological samples play important roles in forensic and clinical investigations. Ingested drugs are excreted in urine as conjugates with endogenous substances such as glucuronic acid; hydrolyzing these conjugates improves the determination of target drugs by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, we sought to improve the enzymatic hydrolysis of glucuronide conjugates of five psychoactive drugs (11-nor-9-carboxy-Δ9-tetrahydrocannabinol, oxazepam, lorazepam, temazepam, and amitriptyline).

METHODS

The efficiency of enzymatic hydrolysis of glucuronide conjugates in urine was optimized by varying temperature, enzyme volume, and reaction time. The hydrolysis was performed directly on extraction columns. This analysis method using LC-MS/MS was applied to forensic autopsy samples after thorough validation.

RESULTS

We found that the recombinant β-glucuronidase B-One® quantitatively hydrolyzed these conjugates within 3 min at room temperature directly on extraction columns. This on-column method saved time and eliminated the loss of valuable samples during transfer to the extraction column. LC-MS/MS-based calibration curves processed with this method showed good linearity, with r2 values exceeding 0.998. The intra- and inter-day accuracies and precisions of the method were 93.0-109.7% and 0.8-8.8%, respectively. The recovery efficiencies were in the range of 56.1-104.5%. Matrix effects were between 78.9 and 126.9%.

CONCLUSIONS

We have established an LC-MS/MS method for five psychoactive drugs in urine after enzymatic hydrolysis of glucuronide conjugates directly on extraction columns. The method was successfully applied to forensic autopsy samples. The established method will have broad applications, including forensic and clinical toxicological investigations.

Liquid chromatography with tandem mass spectrometric method for determination of 52 antibiotics in human whole blood and urine and application to forensic cases

PURPOSE

A rapid and reliable method was developed and validated for the simultaneous analysis of 52 antibiotics (cephalosporins, penicillins, carbapenems, lincosamides, quinolones, nitroimidazoles, macrolides, sulfonamides, tetracyclines, glycopeptide) in urine and whole blood by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

METHOD

Analytes were extracted by dilution or protein precipitation and analyzed on an Agilent 1260 HPLC system coupled to an Agilent 6470 Triple Quadrupole Mass Spectrometer.

RESULTS

The method attended method validation criteria. The limits of detection were equal or lower than 2.0 ng/mL, whereas the limits of quantification ranged from 0.1 to 10.0 ng/mL, from 0.1 to 5.0 ng/mL, in urine and whole blood, respectively. For all analytes, the bias and intra- and inter-day precision values were less than 14.7%. The ranges of recovery values of all antibiotics were 76.5-124.5% in whole blood and 76.3-121.8% in urine, values of the effects were lower than 25% in two matrices. No evidence of carryover was observed. The study of sample stability showed that almost all analytes were stable at 24 °C for 24 h, all analytes were stable at -20 °C for 14 days and at -80 °C for 30 days. Freeze-thaw cycles stability showed that antibiotics were stable except for imipenem. Autosampler stability study showed that all analytes were stable for 24 h, except for imipenem and amoxicillin. Applicability was proven by analyzing authentic whole blood (n = 86) and urine (n = 79) samples from patients under antibiotics treatment. Therefore, this method was applied to the analysis 3 forensic allergy cases, which were positive for at least one analyte.

CONCLUSIONS

A simple, sensitive and high-throughput method for the simultaneous determination of different classes of antibiotics in urine and whole blood samples was developed and applied. This sensitive method was successfully applied to forensic cases.

A case of lacosamide and mirtazapine self-poisoning

Lacosamide is a relatively new antiepileptic drug that exerts its anticonvulsant effect by selectively inactivating sodium channels. Since its launch, it has been used widely for the treatment of intractable epilepsy, but there are scant data on the toxic or lethal blood concentrations. Here, we report a case of drug poisoning following simultaneous high-dose self-administration of lacosamide and mirtazapine. We developed and validated an approach that uses liquid chromatography coupled with electrospray ionization-tandem mass spectrometry to determine the concentrations of lacosamide and mirtazapine in cadaveric blood, urine and liver. Calibration curves showed good linearity (r2 > 0.995), and our method enabled repeatable and accurate quantification, with intra- and inter-assay coefficients of variation not exceeding 10.9 % and 12.8 %, respectively, for each target drug. We used the method to measure the drug concentrations in the blood of a dead victim and found a lacosamide concentration of 91.9 μg/mL and a mirtazapine concentration of 12.0 μg/mL. The blood mirtazapine concentration was in the lethal range, and that of lacosamide was about 10 times the therapeutic range. The synergistically central nervous system depressive and cardiotoxic effects of these drugs may have contributed to the cause of death. We concluded that the cause of death in this case was lacosamide and mirtazapine poisoning.

Use of carbonyldiimidazole as a derivatization agent for the detection of pinacolyl alcohol, a forensic marker for Soman, by EI-GC-MS and LC-HRMS in official OPCW proficiency test matrices

Pinacolyl alcohol (PA), a key forensic marker for the nerve agent Soman (GD), is a particularly difficult analyte to detect by various analytical methods. In this work, we have explored the reaction between PA and 1,1'-carbonyldiimidazole (CDI) to yield pinacolyl 1H-imidazole-1-carboxylate (PIC), a product that can be conveniently detected by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Regarding its GC-MS profile, this new carbamate derivative of PA possesses favorable chromatographic features such as a sharp peak and a longer retention time (RT = 16.62 min) relative to PA (broad peak and short retention time, RT = 4.1 min). The derivative can also be detected by LC-HRMS, providing an avenue for the analysis of this chemical using this technique where PA is virtually undetectable unless present in large concentrations. From a forensic science standpoint, detection of this low molecular weight alcohol signals the past or latent presence of the nerve agent Soman (GD) in a given matrix (i.e., environmental or biological). The efficiency of the protocol was tested separately in the analysis and detection of PA by EI-GC-MS and LC-HRMS when present at a 10 μg/mL in a soil matrix featured in the 44th PT and in a glycerol-rich liquid matrix featured in the 48th Official Organization for the Prohibition of Chemical Weapons (OPCW) Proficiency Test when present at a 5 μg/mL concentration. In both scenarios, PA was successfully transformed into PIC, establishing the protocol as an additional tool for the analysis of this unnatural and unique nerve agent marker by GC-MS and LC-HRMS.

Seized drug reporting of NPS helps to guide regional toxicological practice: A 17 month review between 2022 and 2023

Novel psychoactive substances (NPS) are everchanging and plague forensic laboratories who must identify an unending variety of emerging substances and evolve current methodologies to detect these substances. Identifying potential regional NPS targets and timely examining trends in seized drug data could help mitigate the burden laboratories face. Over 17 months, NPS seized drug data were processed and categorized from three laboratories located across the United States to determine any NPS regional similarities and prevalent NPS drug categories: the South Carolina Law Enforcement Division (SLED), the Sedgwick County Regional Forensic Science Center (SCRFSC), and the Orange County Crime Laboratory (OCCL). Seized drug materials, including pills, powders, and plant material, were primarily analyzed for NPS via gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy. From June 2022 to October 2023, 1940 NPS seized drug identifications were reported by these laboratories with 63 different NPS reported. Novel synthetic opioids (NSO) were the most prevalent NPS class across all three laboratories (55%), with fluorofentanyl accounting for 74% of NSO identifications. This is unsurprising given the fentanyl epidemic in the United States. Furthermore, these data highlighted varying regional NPS seized drug trends: eutylone, a synthetic cathinone, was one of the most frequently identified NPS in SLED, SCRFSC observed the most diverse set of synthetic cannabinoids, and OCCL observed an increased prevalence in the designer benzodiazepine, bromazolam. NPS scope recommendations are a valuable resource for forensic laboratories; however, most focus on a national perspective. Timely analysis and reporting of NPS seized drug data may help to develop regional NPS scope recommendations laboratories may employ.

Vitreous humor in the forensic toxicology of quetiapine and its metabolites

PURPOSE

Τhe aim of the present study was to investigate the use of vitreous humor as an alternative biological material in forensic toxicology for the determination of quetiapine, 7-hydroxy-quetiapine, and nor-quetiapine. The distribution of these substances in vitreous humor was studied by determining and correlating their concentrations in vitreous humor with the respective concentrations in blood.

METHODS

During this study, a method for the determination of these substances was developed, validated and applied to postmortem samples obtained from 16 relative forensic cases. The sample preparation procedure included the isolation of the analytes from vitreous humor and blood samples using solid-phase extraction, with Bond Elut LRC C18 columns followed by derivatization with BSTFA with 1% TMCS prior to GC/MS analysis.

RESULTS

The developed method is characterized by a dynamic range of 10.0-1000.0 ng/mL (R2 ≥ 0.991) for the three substances, with a limit of detection and quantification of 3.0 and 10.0 ng/mL, respectively. Accuracy and precision were below 8.09% and 8.99%, respectively, for both biological materials, while absolute recovery for the three substances was greater than 81%. According to the results, quetiapine, 7-hydroxy-quetiapine, and nor-quetiapine are easily distributed in vitreous humor.

CONCLUSION

The results of the study indicate the usefulness of vitreous humor in toxicological analysis for the determination of these substances, especially when the traditional biological materials are not available. The levels of quetiapine and its metabolites in vitreous humor as well as the vitreous humor to blood concentration ratios can provide important information for a more thorough toxicological investigation of forensic cases.

Analysis of toxicological findings related to immunofluorescence investigations

Background

The subject of this article is the role of forensic toxicology in post-mortem examinations using immunofluorescence methods, its implications and its role in providing conclusive evidence for both criminal and civil proceedings. The aim of the study is to verify the correlation between the mode of death and the ingestion of exogenous substances and, if positive, to identify the category of substances ingested and assess their role in the cause of death.

Materials and methods

A laboratory study was carried out, consisting of several phases: pre-analytical phase; analytical phase; post-analytical phase. The variables analyzed were sex, cause of death, age. Abused substances tested: amphetamines, methamphetamines, barbiturates, benzodiazepines, cocaine, methadone, opiates, tricyclic antidepressants, delta-9-tetrahydrocannabinol (cannabis), alcohol.

Conclusions

Retrospective analysis was performed on a total sample of 55 cases. The most relevant data emerged: cocaine with an incidence of 7.3% (4 cases out of 55), amphetamines with 5.4% (3 cases in total). The results of the screening tests were then subjected to confirmatory tests. There is an association between the use of certain exogenous substances and an increased risk of certain causes of death, such as overdose, traffic accidents, cardiovascular deaths, etc. This paper has highlighted the possibility of using first level immunological tests, such as immunofluorescence, to provide preliminary answers to the judicial authority immediately after autopsy, and a quantitative deepening with further second level tests, such as gas chromatography, as a gold standard to determine the cause of death.

Evaluation of in-house drug evidence testing by King County Medical Examiner's Office in "real-time" fatal overdose surveillance

With the escalating overdose epidemic, many surveillance efforts have appeared. In 2018, King County Medical Examiner's Office (KCMEO) initiated a fatal overdose surveillance project aimed at expediting death certification and disseminating timely information. In this project, KCMEO investigators collected items of evidence of drug use from overdose death scenes, which were tested by five in-house methods, four using handheld devices: TruNarc Raman spectrometer, with and without the manufacture's H-Kit, Rigaku ResQ Raman spectrometer, and MX908 mass spectrometer. The fifth in-house method used fentanyl-specific urine test strips. Results from in-house testing were compared with results from Washington State Patrol (WSP) Materials Analysis Laboratory. From 2019 to 2022, there were 4244 evidence items of drugs and paraphernalia collected from 1777 deaths scenes. A total of 7526 in-house tests were performed on collected specimens, and 2153 tests were performed by the WSP laboratory using standard analytical methods. The WSP results served as reference standards to calculate performance metrics of the in-house methods. Sensitivities, specificities, and predictive values ranged from good to poor depending on the method, drug, and evidence type. Certain drugs were often associated with specific evidence types. Acetaminophen was frequently found in combination with fentanyl. Fentanyl test strips gave good scores for detecting fentanyl; otherwise, in-house methods using handheld devices had poor performance scores with novel drugs and drugs diluted in mixtures. The results showed that in-house testing of drug evidence has value for medical examiner overdose surveillance, but it is resource intensive, and success depends on collaboration with forensic laboratories.

Research Progress on Detection of New Psychoactive Substance Piperazines in vivo

Piperazines are a class of new psychoactive substances with hallucinogenic effects that affect the central nervous system by affecting the level of monoamine neurotransmitters. Abuse of piperazines will produce stimulating and hallucinogenic effects, accompanied by headache, dizziness, anxiety, insomnia, vomiting, chest pain, tachycardia, hypertension and other adverse reactions, and may even cause cardiovascular diseases and multiple organ failure and lead to death, seriously affecting human physical and mental health and public safety. The abuse of new psychoactive substance piperazines has attracted extensive attention from the international community. The study of its pharmacological toxicology and analytical methods has become a research hotspot in the field of forensic medicine. This paper reviews the in vivo processes, sample treatment and analytical methods of existing piperazines, in order to provide reference for forensic identification.

A validated dilute-and-shoot LC-MS-MS urine screening for the analysis of 95 illicit drugs and medicines: Insights from clinical and forensic Brazilian cases

Urine toxicological analysis is a relevant tool in both clinical and forensic scenarios, enabling the diagnosis of acute poisonings, elucidation of deaths, verification of substance use in the workplace and identification of drug-facilitated crimes. For these analyses, the dilute-and-shoot technique associated with liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) is a promising alternative since it has demonstrated satisfactory results and broad applicability. This study developed and validated a comprehensive LC-MS-MS screening method to analyze 95 illicit drugs and medicines in urine samples and application to clinical and forensic Brazilian cases. The dilute-and-shoot protocol was defined through multivariate optimization studies and was set using 100 µL of sample and 300 µL of solvent. The total chromatographic run time was 7.5 min. The method was validated following the recommendations of the ANSI/ASB Standard 036 Guideline. The lower limits of quantification varied from 20 to 100 ng/mL. Within-run and between-run precision coefficient of variations% were <20%, and bias was within ± 20%. Only 4 of the 95 analytes presented significant ionization suppression or enhancement (>25%). As proof of applicability, 839 urine samples from in vivo and postmortem cases were analyzed. In total, 90.9% of the analyzed samples were positive for at least one substance, and 78 of the 95 analytes were detected. The most prevalent substances were lidocaine (40.2%), acetaminophen (38.0%) and benzoylecgonine (31.5%). The developed method proved to be an efficient and simplified alternative for analyzing 95 therapeutic and illicit drugs in urine samples. Additionally, the results obtained from sample analysis are essential for understanding the profile of Brazilian substance use, serving as a valuable database for the promotion of health and safety public policies.

α-Pyrrolidinohexanophenone (α-PHP) vs. α-pyrrolidinoisohexanophenone (α-PiHP): A toxicological investigation about plasma concentrations and behavior in forensic routine cases

New psychoactive substances (NPS), like pyrrolidinophenones, are still very present on the illegal drug market. The presented study reports on two members of this substance group, α-pyrrolidinohexanophenone (α-PHP) and α-pyrrolidinoisohexanophenone (α-PiHP), which occurred in forensic routine cases in the last 6 years. α-PHP could be detected predominantly by a validated liquid chromatography-tandem mass spectrometry (LC-MS-MS) method in 33 authentic human plasma samples and α-PiHP in 8. α-PHP concentrations ranged from ca. 0.75 to 128 µg/L (mean: 23.2, median: 16.3) and α-PiHP concentrations from 7.33 to 118 µg/L (mean: 44.7, median: 33.7, quantified via α-PHP). Individuals were predominantly male and middle aged. As different studies have shown, some pyrrolidinophenones are able to cause aggressive behavior. Therefore, we set out to investigate the relation of α-PHP and α-PiHP plasma concentrations and the behavior of the consumers, reported by police and medical experts. Part of the subjects showed aggressive behavior, including agitation and restlessness. Lethargic and unremarkable behavior might be explained by co-consumption of other drugs, such as opiates/opioids, benzodiazepines, pregabalin or alcohol as well as by drug tolerance and subacute effects of stimulants. Multi-drug use could be detected in all cases; also stimulating substances and multiple different pyrrolidinophenones were determined. Nevertheless, users of α-PHP and α-PiHP showed a tendency to act aggressively, possibly triggered by a high selectivity for dopamine transporter inhibition. In accordance, committed offenses were often violent crimes. This might be considered in terms of toxicological assessment of criminal responsibility and driving ability.

Insights into the human metabolism of hexahydrocannabinol by non-targeted liquid chromatography-high-resolution tandem mass spectrometry

Hexahydrocannabinol (HHC), 6,6,9-trimethyl-3-pentyl-6a,7,8,9,10,10a-hexahydrobenzo[c]chromen-1-ol, is a semi-synthetic cannabinoid that has presented challenges to analytical laboratories due to its emergence and spread in the drug market. The lack of information on human pharmacokinetics hinders the development and application of presumptive and confirmatory tests for reliably detecting HHC consumption. To address this knowledge gap, we report the analytical results obtained from systematic forensic toxicological analysis of body-fluid samples collected from three individuals suspected of drug-impaired driving after HHC consumption. Urine and plasma samples were analyzed using non-targeted liquid chromatography-high-resolution tandem mass spectrometry. The results provided evidence that HHC undergoes biotransformation reactions similar to other well-characterized cannabinoids, such as ∆9-tetrahydrocannabinol or cannabidiol. Notably, HHC itself was only detectable in plasma samples, not in urine samples. The observed Phase I reactions involved oxidation of C11 and the pentyl side chain, leading to corresponding hydroxylated and carboxylic acid species. Additionally, extensive glucuronidation of HHC and its Phase I metabolites was evident.

False-positive MDA findings in HRMS-based screening of putrefied postmortem blood samples-Identification of the interference as N-acetyltyramine

An unidentified compound in putrefied postmortem blood samples showed identical accurate mass and chromatographic behavior as 3,4-methylenedioxyamphetamine (MDA) and led to false-positive preliminary screening results. The aim of the study was to identify this unknown interference. Postmortem blood samples were analyzed after protein precipitation on a QExactive Focus high-resolution mass spectrometer (Thermo Fisher, Germany) coupled to a RP C18 column (Macherey-Nagel, Germany). Based on the analysis of mass spectrometry (MS) adducts and isotope ratios using fullscan (m/z 134-330) information, the empiric formula of the protonated molecule [M + H]+ of the unknown compound was found to be C10H14O2N (+ 0.6 ppm). Product ion spectra recorded using normalized collision energy 22% showed a base peak of C8H9O1 (+ 1.5 ppm) and a low-abundant water loss to C7H9 (+ 1.9 ppm), neutral losses of C2H2O and NH3 were found. Based on fullscan and MS-MS information and under consideration of the observed order of neutral losses, the compound was presumptively identified as N-acetyltyramine. This assumption was supported by SIRIUS software showing a SIRIUS score of 99.43% for N-acetyltyramine. Finally, the putative structure annotation was confirmed by a reference compound. The described false-positive MDA findings could be attributed to the presence of N-acetyltyramine in putrefied blood samples. Being an isomer of MDA, N-acetyltyramine could not be distinguished by high-resolution data of the protonated molecules. The presented results once again highlight that false-positive findings may occur even in hyphenated high-resolution mass spectrometry (HRMS) when using full-scan information only.

Gaps in forensic toxicological analysis: The veiled abrin

Abrus precatorius is an herbaceous, flowering plant that is widely distributed in tropical and subtropical regions. Its toxic component, known as abrin, is classified as one of the potentially significant biological warfare agents and bioterrorism tools due to its high toxicity. Abrin poisoning can be utilized to cause accidents, suicides, and homicides, which necessitates attention from clinicians and forensic scientists. Although a few studies have recently identified the toxicological and pharmacological mechanisms of abrin, the exact mechanism remains unclear. Furthermore, the clinical symptoms and pathological changes induced by abrin poisoning have not been fully characterized, and there is a lack of standardized methods for identifying biological samples of the toxin. Therefore, there is an urgent need for further toxicopathologic studies and the development of detection methods for abrin in the field of forensic medicine. This review provides an overview of the clinical symptoms, pathological changes, metabolic changes, toxicologic mechanisms, and detection methods of abrin poisoning from the perspective of forensic toxicology. Additionally, the evidence on abrin in the field of forensic toxicology and forensic pathology is discussed. Overall, this review serves as a reference for understanding the toxicological mechanism of abrin, highlighting the clinical applications of the toxin, and aiding in the diagnosis and forensic identification of toxin poisoning.

Strategies to detect trace methamphetamine contamination on hard surfaces: Assessing realistic performance of commercially available presumptive tests and a laboratory-based LC-MS/MS method

Recreational methamphetamine production and heavy use can result in dwelling contamination that is difficult to detect. First responders and public health officials may use commercially available trace methamphetamine detection (presumptive) test kits to understand apparent and hidden dangers in impacted dwellings. Here, we assessed the limit of detection (LOD) of several commercially available presumptive test kits using simulated contaminated hard surfaces. Pyrex petri dishes were spiked with aliquots of methanolic methamphetamine solutions to reach desired simulated contamination levels. Commercially available presumptive tests were conducted according to manufacturer instructions and using included sample preparation materials, when available. Additionally, a laboratory-based liquid chromatography-triple quadrupole mass spectrometer (LC-MS/MS) trace methamphetamine quantification method was developed and validated using the EZSTATSG2 tool. For the LC-MS/MS method, samples were collected using 2-ply alcohol prep pads and methamphetamine was extracted using a 1:1 (v:v) methanol: water solution. Most presumptive tests considered were able to detect trace levels of methamphetamine extracted from hard surfaces, with LOD ranging from 0.10-15.00 μg/sample. Comparatively, the laboratory-based LC-MS/MS LOD was 0.05 μg/sample and limit of quantitation was 0.10 μg/sample. The LC-MS/MS method may be useful when the presence of dust or other contaminants interferes with presumptive test interpretation or reliability. Costs of presumptive tests varied from several dollars to tens of dollars, which is included alongside LOD results to aid stakeholders in identifying which test(s) are the best fit for purpose. Therefore, first responders, public health officials, and other stakeholders have several options for assessing trace methamphetamine contamination.

An improved Simon reaction method to discriminate between methamphetamine and false-positive substances

The conventional methamphetamine (MA) detection method using the Simon reaction can be affected by false positives owing to compounds similar to aliphatic secondary amines. In this study, we examined the new Simon reaction to improve the qualitative accuracy of MA detection to discriminate substances that give false positives in a conventional Simon reaction. After the conventional Simon reaction for MA and false positives (N-isopropylbenzylamine (NIP-BA), N-methylbenzylamine (NMe-BA), L-proline (Pro), and L-hydroxyproline (HYP)), which are colored blue, di-tert-butyl dicarbonate (t-Boc) reagent was added, and color tone changes were observed. When t-Boc was added to the false positives (NIP-BA, NMe-BA, Pro, and HYP), the colors of MA, Pro, and HYP changed to purple; NIP-BA changed to blue; and NMe-BA changed to light pink after 3 min. These results suggested that MA can be differentiated from NIP-BA and NMe-BA. Furthermore, the solid-phase chromogenic method was examined, and it was confirmed that MA could be differentiated from Pro and HYP. The method developed in this study should increase the accuracy of MA appraisal at crime scenes and contribute to the reduction of misclassifications arising from false-positive substances.

Is it really possible to kill with insulin without leaving traces? From lifesaver to killer, the issues surrounding the analytical characterization of postmortem insulin illustrated by an exemplary case

Evidence of an insulin overdose is very complicated in the medico-legal field. The analysis and subsequent interpretation of results is complex, especially when treating postmortem blood samples. The instability of insulin, the special pre-analytical conditions and the absence of specific analytical methods has led most laboratories not to analyze insulin in their routine with a consequent underestimation of cases. This paper aims to assess the difficulties associated with the analytical characterization of insulin by describing a case that typically represents most of the inconveniences encountered following a suspected insulin overdose. The case concerns a man found dead at home by his brother. After an external examination, which did not reveal a specific cause of death, toxicological analysis was requested which did not reveal any substance of toxicological interest. Only 9 months later, it was reported to the toxicologist that the subject was diabetic, on insulin lispro treatment and that three empty syringes were found next to his body. Following analysis by LC-high-resolution mass spectrometry, the presence of insulin lispro at a concentration of 1.1 ng/mL, a therapeutic concentration, was evidenced. Despite the low concentration found, overdose cannot be excluded and this paper will describe the criteria evaluated to reach this conclusion. This case highlights that the interpretation of a postmortem insulin concentration is very complex and requires the evaluation of various elements including the circumstances of death, the subject's medical history, the interval between death and sampling and the sample storage.

Challenges and future trends of forensic toxicology to keep a cut above the rest

Forensic toxicology faces several challenges in research and daily practice, including new drugs and futuristic technologies requiring innovative testing methods and continuous education and training of professionals. One of the most pressing issues in recent years is the emergence of novel psychoactive substances, often created by modifying the chemical structure of existing drugs to produce compounds with similar effects that are not yet regulated and lack standardized references. To overcome this challenge, forensic toxicologists have employed a range of analytical methods, including qualitative and quantitative analysis using highly sensitive technologies such as liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS), which are the most reliable and accurate methods for detecting drugs in biological samples. Liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) is becoming the gold standard for detecting controlled substances, their derivatives and metabolites. Despite advancements in testing methods, challenges persist in forensic toxicology. As such, the field must invest in research and development to improve testing methods, utilize cutting-edge technologies, increase funding for training programs, and promote multidisciplinary interactions.

Development of an innovative analytical method for forensic detection of cocaine, antidepressants, and metabolites in postmortem blood using magnetic nanoparticles

Cocaine and antidepressants rank high globally in substance consumption, emphasizing their impact on public health. The determination of these compounds and related substances in biological samples is crucial for forensic toxicology. This study focused on developing an innovative analytical method for the determination of cocaine, antidepressants, and their related metabolites in postmortem blood samples, using unmodified commercial Fe3O4 nanoparticles as a sorbent for dispersive magnetic solid-phase extraction (m-d-SPE), coupled with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis. An aliquot of 100 µL of whole blood and 5 µL of the internal standard pool were added to 30 mg of nanoparticles. The nanoparticles were separated from the sample using a neodymium magnet inserted into a 3D-printed microtube rack. The liquid was then discarded, followed by desorption with 300 µL of 1/1/1 acetonitrile/methanol/ethyl acetate. The sample was vortexed and separated, and 1.5 µL of the organic supernatant was injected into the LC-MS/MS. The method was acceptably validated and successfully applied to 263 postmortem blood samples. All samples evaluated in this study were positive for at least one substance. The most frequent analyte was benzoylecgonine, followed by cocaine and cocaethylene. The most common antidepressants encountered in the analyzed samples were citalopram and fluoxetine, followed by fluoxetine's metabolite norfluoxetine. This study describes the first report of this sorbent in postmortem blood analysis, demonstrating satisfactory results for linearity, precision, accuracy, and selectivity for all compounds. The method's applicability was confirmed, establishing it as an efficient and sustainable alternative to traditional techniques for forensic casework.

Chemical investigation of biological trace evidence; toxicological screening of waste residues obtained from DNA extraction processes

In a forensic scenario, if biological stains are found in very small quantities, these are usually collected for DNA analyses, considered essential for the forensic investigation and thus excluding possible investigations by other forensic disciplines as forensic toxicology. We developed an experimental study to evaluate the feasibility of analyzing DNA extraction residues obtained from DNA extraction procedures to perform toxicological analysis, with the aim to extract both genetic and toxicological information without affecting or compromising the genetic sample and/or DNA extraction. DNA extraction from four blood samples (fortified with 5 molecules of interest with a final concentrations of 1 µg/mL, 100 ng/mL, 10 ng/mL and 5 ng/mL, respectively) were analyzed with QIAGEN QIAmp® DNA Mini kit. Three waste residues collected from the DNA extraction were analyzed for the toxicological investigation via Solid-Phase Extraction and High-Performance Liquid Chromatography-Tandem Mass Spectrometry analyses (Thermo Scientific™ TSQ Fortis™ II Triple-Quadrupole Mass Spectrometer). The analytical investigation revealed that our analytes of interest were detected in two different residues of the DNA extraction procedure, allowing both genetic and toxicological analyses without affecting the DNA identification. At last, the experimental protocol was applied to a hypothetical case, with encouraging results and allowing the identification of our molecules of interest.

Evaluation of organophosphorus pesticide tyrosine adducts for postmortem change by human serum albumin with liquid chromatography quadrupole Orbitrap mass spectrometry

Organophosphorus pesticides (OPPs) having a phosphate ester moiety, such as malathion (MA) and methidathion (DMTP), are widely used and have been detected in many fatal cases of accidental exposure or suicide in Japan. In forensic toxicology, the accurate determination of blood OPP concentration is mandatory to prove death by OPP poisoning. However, fatal pesticide concentration in blood at autopsy varies depending on the circumstances surrounding the dead body. In this study, we found that 16 OPPs were degraded by human serum albumin (HSA) in a temperature-dependent fashion. The mechanism underlying MA, DMTP, azinphos-methyl, etrimfos, fenthion (MPP), pirimiphos-methyl, (E)-dimethylvinphos, (Z)-dimethylvinphos, vamidothion, edifenphos (EDDP), fosthiazate, and pyraclofos degradation involves the formation of adducts with tyrosine residues in HSA. The mass spectra obtained by liquid chromatography quadrupole Orbitrap mass spectrometry revealed that phosphate ester amino acid adducts such as Y-adduct1, Y-adduct2, Y-adduct3, Y-adduct4, and Y-adduct5 were formed in HSA solution incubated with OPPs. These results indicate that the 16 OPPs are postmortem changed by HSA. The detection of phosphate ester amino acid adducts such as Y-adduct1, Y-adduct2, Y-adduct3, Y-adduct4, and Y-adduct5, instead of MA, DMTP, azinphos-methyl, etrimfos, MPP, pirimiphos-methyl, (E)-dimethylvinphos, (Z)-dimethylvinphos, vamidothion, EDDP, fosthiazate, and pyraclofos per se, may be used to determine death by these OPPs poisoning.

Screening for Forensically Relevant Drugs Using Data-Independent High-Resolution Mass Spectrometry

Forensic and clinical laboratories are expected to provide a rapid screening of samples for a wide range of analytes; however, the ever-changing landscape of illicit substances makes analysis complicated. There is a great need for untargeted methods that can aid these laboratories in broad-scope drug screening. Liquid chromatography hyphenated with high-resolution mass spectrometry (LC-HRMS) has become a popular technique for untargeted screening and presumptive identification of drugs of abuse due to its superior sensitivity and detection capabilities in complex matrices. An untargeted extraction and data acquisition method was evaluated for the broad screening of high-priority drugs of abuse in whole blood. A total of 35 forensically relevant target analytes were identified and extracted at biologically relevant low and high (10× low) concentrations from whole blood using supported liquid extraction. Data-independent acquisition was accomplished using ultraperformance liquid chromatography and a quadrupole time-of-flight mass spectrometry. Results were acceptable for screening assays, with limits of detection at or below the recommended low-concentration cutoffs for most analytes. Analyte ionization varied from 30.1 to 267.6% (average: 110.5%) at low concentrations and from 8.6 to 383.5% (average: 93.6%) at high concentrations. Extraction recovery ranged from 8.5 to 330.5% (average: 105.3%) at low concentrations and from 9.4 to 127.5% (average: 82.7%) at high concentrations. This variability was also captured as precision, ranging from 4.7 to 135.2% (average: 36.5%) at low concentrations and from 0.9 to 59.0% (average: 21.7%) at high concentrations. The method described in this work is efficient and effective for qualitative forensic toxicology screening, as demonstrated by analysis of 166 authentic suspected impaired driver and postmortem specimens. That said, it is critical that laboratories establishing untargeted LC-HRMS screening assays be aware of the strengths and limitations across diverse drug categories and chemical structures.

A quantitative LC-MS/MS analysis of Xylazine, p-Fluorofentanyl, Fentanyl and Fentanyl-Related compounds in postmortem blood

The purpose of this study was to develop and validate a method to quantitate the veterinary sedative xylazine as well as 4-anilino-N-phenethylpiperidine (4-ANPP), acetyl fentanyl, fentanyl, norfentanyl, and p-fluorofentanyl in blood utilizing liquid chromatography tandem mass spectrometry. This method also qualitatively monitors for the presence of o-fluorofentanyl and m-fluorofentanyl isomers. UCT Clean Screen® DAU extraction columns were utilized to isolate the analytes in postmortem blood samples. The extracts were eluted, evaporated, reconstituted, and then analyzed using a Waters Acquity™ UPLC coupled a triple quadrupole mass spectrometer. The lower limit of quantitation was determined to be 0.1 ng/mL for all analytes, except for xylazine (0.2 ng/mL). The upper limit of quantitation for all analytes was 100 ng/mL. No interferences from matrix, internal standard, or common drug analytes were observed. Bias (-13.1-4.6 %) and precision (-13.14-10.3 %) fell within the acceptable ± 20 % criteria range. Dilution integrity at x2, x10, and x100 was evaluated and all results were within ± 20 % of the target concentration. Processed extract stability was evaluated after 72 h and all results were within ± 20 % of the analyte initial concentration. Matrix effects were the most prominent with xylazine, but deemed acceptable as the deuterated internal standard also observed comparable enhancement. Analysis of 89 postmortem blood samples by this method resulted in positive results for fentanyl (0.27-66 ng/mL, n = 82), xylazine (0.24-958 ng/mL, n = 21), 4-ANPP (0.10-38 ng/mL, n = 72), acetyl fentanyl (0.18-1.5 ng/mL, n = 3), p-fluorofentanyl (0.11-33 ng/mL, n = 30), and norfentanyl (0.10-98 ng/mL, n = 73).

[Adequate assessment of linear function of calibration according to GOST R ISO 11095-2007 for ethanol mass concentration measurement]

OBJECTIVE

To assess the adequacy of linear function of calibration according to GOST R ISO 11095-2007 for ethanol mass concentration measurement using internal reference materials (RMs).

MATERIAL AND METHODS

An experiment on calibration in accordance with the GOST R ISO 11095-2007 National standard of the RF was carried out using internal RMs, namely aqueous solutions of ethanol at different concentrations. Measurements were performed for two subbands of ethanol concentrations at RMs: 0.15-1.05 and 1.0-7.0 mg/ml - according to the certified methodology.

RESULTS

The graphs of the calibration's functions based on experimental data are consistent with the assumption of the calibration function's linearity, as well as the assumption of the standard deviation's constance of residues is equitable for two subbands of RMs.

CONCLUSION

Proven linear models in the calibration experiment may be recommended for use in the ethanol mass concentration measurement.

[Forensic toxicological characteristics of modern occupational injuries]

OBJECTIVE

To analyze the contribution of alcohol and drug intoxication to fatal occupational injuries and sudden death at the workplace in Moscow.

MATERIAL AND METHODS

A number of death cases of various organizations' employees equal 357 in Moscow in 2023 were investigated. The mean age of the deceased was 48.29±13.9 years, 92.4% of them were men.

RESULTS

Ethanol in blood has been determined in 15% of the deceased. Narcotic drugs and psychotropic medications have been found in 6.7% of cases. Signs of chronic intoxication have been established in 16.5% of the deceased. Chronic intoxication accompanied or aggravated the course of 70% of cardiomyopathies. The proportion of deceased in an accident at an industry or construction site equal 23.9%, as well as 1/2 of the deceased in an accident on the street and in a residential building were impaired by alcohol.

CONCLUSION

The study of the contribution of alcohol and drug consumption to occupational mortality will allow to plan measures for reducing the mortality of working-age population.