Preanalytic aspects in postmortem toxicology

Postmortem metabolomics: influence of time since death on the level of endogenous compounds in human femoral blood. Necessary to be considered in metabolome study planning?

INTRODUCTION

The (un)targeted analysis of endogenous compounds has gained interest in the field of forensic postmortem investigations. The blood metabolome is influenced by many factors, and postmortem specimens are considered particularly challenging due to unpredictable decomposition processes.

OBJECTIVES

This study aimed to systematically investigate the influence of the time since death on endogenous compounds and its relevance in designing postmortem metabolome studies.

METHODS

Femoral blood samples of 427 authentic postmortem cases, were collected at two time points after death (854 samples in total; t1: admission to the institute, 1.3-290 h; t2: autopsy, 11-478 h; median ∆t = 71 h). All samples were analyzed using an untargeted metabolome approach, and peak areas were determined for 38 compounds (acylcarnitines, amino acids, phospholipids, and others). Differences between t2 and t1 were assessed by Wilcoxon signed-ranked test (p < 0.05). Moreover, all samples (n = 854) were binned into time groups (6 h, 12 h, or 24 h intervals) and compared by Kruskal-Wallis/Dunn's multiple comparison tests (p < 0.05 each) to investigate the effect of the estimated time since death.

RESULTS

Except for serine, threonine, and PC 34:1, all tested analytes revealed statistically significant changes between t1 and t2 (highest median increase 166%). Unpaired analysis of all 854 blood samples in-between groups indicated similar results. Significant differences were typically observed between blood samples collected within the first and later than 48 h after death, respectively.

CONCLUSIONS

To improve the consistency of comprehensive data evaluation in postmortem metabolome studies, it seems advisable to only include specimens collected within the first 2 days after death.

Dispersive liquid-liquid microextraction (DLLME) for determination of tricyclic antidepressants in whole blood and plasma samples and analysis by liquid chromatography with diode array detector (LC-DAD)

Microextractions have been developed for the tricyclic antidepressants (TCAs) analysis in biological matrices, including dispersive liquid-liquid microextraction (DLLME). The proposed DLLME employed 490 µL of biological sample (whole blood or plasma), which were added 15 mg of NaCl, 10 µL of medazepam as internal standard (10 µg/mL) and 100 µL of 2 M NaOH. This mixture was homogenized by vortex (2800 rpm/10 s) and 400 µL of hexane (extractor solvent) with 600 µL of methanol (dispersing solvent) were added to the sample. After the vortex step (2800 rpm/5 s), an ultrasonic bath for 300 s was employed. Then, this content was centrifuged (10 min/10000 rpm), organic phase was collected and dried under air flow. After, 30 µL of the mobile phase was used for resuspension and 20 µL is injected into LC-DAD. This method was optimized and fully validated according to UNODC and SWGTOX guidelines, reaching limits of detection equivalent to analytical methodologies that employ mass spectrometry (MS). Also, it was applied in real cases involving suspected exposure to TCAs. So, the developed DLLME for the determination of TCAs in whole blood and plasma samples proved to be a simple, reliable, robust and reproducible method that can be used in toxicology and clinical laboratories.

Preanalytical factors influencing the results of ethanol analysis in postmortem specimens

Excessive drinking and drunkenness are underlying factors in many fatal accidents, which make the quantitative determination of ethanol in postmortem (PM) specimens an essential part of all unnatural death investigations. The same analytical methods are used to determine ethanol in blood taken from living and deceased persons although the interpretation of the results is more complicated in medical examiner cases owing to various preanalytical factors. The biggest problem is that under anaerobic conditions ethanol can be produced naturally in decomposed bodies by microbial activity and fermentation of blood glucose. Ways are needed to differentiate antemortem ingestion of ethanol from PM synthesis. One approach involves the determination of ethanol in alternative specimens, such as bile, cerebrospinal fluid, vitreous humor and/or urine, and comparison of results with blood alcohol concentration (BAC). Another approach involves the analysis of various alcohol biomarkers, such as ethyl glucuronide, ethyl sulfate and/or phosphatidylethanol or the urinary metabolites of serotonin 5-hydroxytryptophol/5-hydroxyindoleacetic acid (5-HTOL/5-HIAA). If ethanol had been produced in the body by microbial activity, the blood samples should also contain other low-molecular volatiles, such as acetaldehyde, n-propanol and/or n-butanol. The inclusion of 1-2% w/v sodium or potassium fluoride, as an enzyme inhibitor, in all PM specimens is essential to diminish the risk of ethanol being generated after sampling, such as during shipment and storage prior to analysis. Furthermore, much might be gained if the analytical cut-off for reporting positive BAC was raised from 0.01 to 0.02 g% when PM blood is analyzed. During putrefaction low BACs are more often produced after death than high BACs. Therefore, when the cadaver is obviously decomposed, a pragmatic approach would be to subtract 0.05 g% from the mean analytical result. Any remaining BAC is expected to give a more reliable indication of whether alcohol had been consumed before death.

Hair analysis in postmortem investigations: Case of a skeletonized body

Analysis of hair collected from putrefied or skeletal bodies is always complex and must take into account several pitfalls, such as external contamination and contamination by biological fluids. This work presents a case of particular complexity. A skeletonized body was discovered on a country road. A tuft of brown hair, detached from the scalp, irregular in length, non-oriented, in contact with soil and vegetation, was removed. An anthropological examination was carried out and genetic samples were taken from the right femoral shaft. After about 10 washes with warm water and dichloromethane, the tuft of hair was analyzed without segmentation. General unknown screening was performed by liquid chromatography system coupled to a high-resolution mass spectrometry (LC-HRMS) after incubation in pH 9.5 borate buffer and liquid-liquid extraction. Specific Multiple Reaction Monitoring (MRM) methods for date rape drugs were carried out by liquid chromatography system coupled to a tandem mass spectrometry (LC-MS/MS). The anthropological examination allowed to determine that the victim was a female individual, over 60 years old, the death dating from 3 months to 1 year. Comparison of the DNA results with the Missing Persons Index led to the identification, a 60-year-old woman who disappeared 5 months earlier. Hair analysis showed the presence of oxazepam (361 pg/mg), nordiazepam (54 pg/mg), and alimemazine (5 pg/mg). The interpretation of these concentrations is extremely difficult due to the risk of degradation of the hair cuticle during prolonged stay in the soil, as well as of contamination by putrefactive fluids. The authors discuss the value of using multiple biological and non-biological matrices in this context to improve the interpretation of the results.

Postmortem redistribution of amphetamines and benzodiazepines in humans: Important variables that might be influencing the central blood / peripheral blood ratio

INTRODUCTION

The primary objective of postmortem forensic toxicology is to determine if toxicological substances detected in bodily material of victims have contributed to the death of the victim. Interpretation of postmortem drug concentrations is hindered by the fact that time and site dependent variations in postmortem drug concentrations occur, as a result of postmortem redistribution (PMR). An often-used marker for the occurrence of PMR, is the cardiac blood concentration/peripheral blood concentration ratio (C/P ratio) of a drug. In this study, we investigated the relationship between 13 variables and the C/P ratios of amphetamines and benzodiazepines.

METHOD

Toxicological results of all postmortem cases that were positive for amphetamines (amphetamine, MDMA, MDA) and/or benzodiazepines (diazepam, desmethyldiazepam, temazepam, oxazepam, midazolam, α-hydroxymidazolam) investigated by the Netherlands Forensic Institute between January 1 2010 and July 31 2020 were reviewed. A total of 112 amphetamine positive cases (224 paired specimen) and 179 benzodiazepine positive cases (358 paired specimen) were selected. The C/P ratios were determined for all selected cases. Ratios were compared between subgroups by performing either a Mann-Whitney U test or a Kruskal-Wallis test followed by post-hoc Mann-Whitney U test.

RESULTS

After dividing cases in quartiles based on their amphetamine concentration in femoral blood, the amphetamine C/P ratio was significantly lower in cases with a high amphetamine concentration (quartile 4) compared to cases with a low amphetamine concentration (quartiles 1 and 2) with median C/P ratios of 1.6, 2.4 and 2.2, respectively (p-value<0.001 and p-value=0.001, respectively). The MDA C/P ratio was significantly higher in cases where trauma was the cause of death compared to cases where intoxication was the cause of death with median C/P ratios of 3.3 and 1.6, respectively (p-value<0.001). The MDA C/P ratio was also significantly lower in cases where resuscitation was attempted compared to cases where no resuscitation was attempted with median C/P ratios of 1.6 and 2.4, respectively (p-value=0.003). However, a significant dependency between the variables cause of death and attempted resuscitation was observed. No significant differences in benzodiazepine C/P ratios were observed between subgroups of any of the investigated variables. However, the low p-value of BMI suggests a potential difference in midazolam C/P ratio between BMI subgroups (p-value=0.027).

CONCLUSION

When interpreting postmortem toxicological results, it might prove useful to take the above-mentioned variables into account.

In vitro studies on the dependence of drug deposition in dentin on drug concentration, contact time, and the physicochemical properties of the drugs

The chemical analysis of dental hard tissues can provide information on previous drug use due to the deposition of drugs into this tissue. For the interpretation of analytical results in, e.g., postmortem toxicology or regarding archeological samples, the influence of drug dosing, consumption frequency, duration of intake and type of drug on analyte concentrations in teeth has to be characterized. To approximate these correlations, in vitro models were applied to investigate the time dependency of drug deposition via and against pulp pressure (perfusion studies) and the concentration dependency of drug deposition via oral cavity (incubation study) as well as the influence of de- and remineralization (pH cycling) on the incorporation of drugs in bovine dentin pellets. Some of the drugs of abuse most relevant in forensic case work (amphetamines, opiates, cocaine and benzoylecgonine) were applied. Concentrations in dentin samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after pulverization and extraction via ultrasonication with methanol. The studies showed that drug deposition in dentin likely depends on the physicochemical properties of the drug molecules as well as on the duration of contact with drugs via the blood stream and on drug concentrations present in the oral cavity. Higher drug concentrations in teeth can result from a more frequent or longer drug use. In addition, intake of higher doses or oral/inhalative consumption can also be expected to lead to higher drug concentrations. These findings can be helpful for the interpretation of postmortem cases.

11-Nor-9-Carboxy Tetrahydrocannabinol Distribution in Fluid from the Chest Cavity in Cannabis-Related Post-Mortem Cases

In this study, the presence of 11-nor-Δ9-carboxy tetrahydrocannabinol (THC-COOH) in postmortem fluid obtained from the chest cavity (FCC) of postmortem cases collected from drug-related fatalities or criminal-related deaths in Jeddah, Saudi Arabia, was investigated to evaluate its suitability for use as a complementary specimen to blood and biological specimens in cases where no bodily fluids are available or suitable for analysis. The relationships between THC-COOH concentrations in the FCC samples and age, body mass index (BMI), polydrug intoxication, manner, and cause of death were investigated.

METHODS

Fifteen postmortem cases of FCC were analyzed using fully validated liquid chromatography-positive-electrospray ionization tandem mass spectrometry (LC-MS/MS).

RESULTS

FCC samples were collected from 15 postmortem cases; only THC-COOH tested positive, with a median concentration of 480 ng/mL (range = 80-3010 ng/mL). THC-COOH in FCC were higher than THC-COOH in all tested specimens with exception to bile, the median ratio FCC/blood with sodium fluoride, FCC/urine, FCC/gastric content, FCC/bile, FCC/liver, FCC/kidney, FCC/brain, FCC/stomach wall, FCC/lung, and FCC/intestine tissue were 48, 2, 0.2, 6, 4, 6, 102, 11, 5 and 10-fold, respectively.

CONCLUSION

This is the first postmortem report of THC-COOH in the FCC using cannabinoid-related analysis. The FCC samples were liquid, easy to manipulate, and extracted using the same procedure as the blood samples. The source of THC-COOH detected in FCC could be derived from the surrounding organs due to postmortem redistribution or contamination due to postmortem changes after death. THC-COOH, which is stored in adipose tissues, could be a major source of THC-COOH found in the FCC.

Postmortem redistribution of cocaine and its metabolites, benzoylecgonine and ecgonine methyl ester in humans: Important variables that might be influencing the central blood / peripheral blood ratio

INTRODUCTION

A big challenge in forensic toxicology is the correct interpretation of the results of quantitative analyses in postmortem cases. Postmortem drug concentrations not necessarily reflect the drug concentrations at the time of death, due to postmortem changes in drug concentrations caused by postmortem redistribution (PMR). Cardiac blood is more prone to PMR related concentration changes than peripheral blood. Because of this difference in susceptibility to PMR related concentration changes, the ratio of cardiac blood concentration/peripheral blood concentration (C/P) of a drug is an often-used marker of PMR. In this study, we investigated the relationship between different potentially significant variables and the C/P ratios of cocaine, benzoylecgonine (BE) and ecgonine methyl ester (EME) in humans. The aim was to elucidate the mechanisms involved in PMR of these substances and potentially provide guidelines aiding forensic toxicologists in the interpretation of postmortem quantitative results of cocaine and its metabolites. To differentiate between postmortem concentration changes due to redistribution versus degradation of cocaine, the relationships between these variables and metabolite/cocaine ratios were investigated as well.

METHOD

Toxicological results of all postmortem cases that were positive for cocaine, BE and/or EME investigated by the Netherlands Forensic Institute between January 1st 2010 and July 31st 2020 were reviewed. The C/P ratios, BE/cocaine ratios and EME/cocaine ratios were determined for all selected cases. Cocaine, BE and/or EME were quantified in both femoral blood and cardiac blood in a total of 148 cases. Ratios were compared between subgroups by performing either a Mann-Whitney U test or a Kruskal-Wallis test followed by post-hoc Mann-Whitney U test.

RESULTS

A statistically significant difference in C/P ratio of EME was observed between trauma and non-trauma cases with median C/P ratios of 2.03 and 1.57, respectively (p value=0.001). A statistically significant difference in EME/cocaine ratio was observed between the BMI subgroups 18.5 - 25.0 kg/m2 and> 25 kg/m2 with median EME/cocaine ratios of 3.79 and 1.58, respectively (p-value<0.001).

CONCLUSION

Postmortem cocaine concentrations should be interpreted with caution, considering the occurrence of both PMR and postmortem degradation. When interpreting postmortem toxicological results in cocaine-related fatalities, it might prove useful to take the above-mentioned variables into account.

In the case of extensively putrefied bodies, the analysis of entomological samples may support and complement the toxicological results obtained with other alternative matrices

Entomotoxicological analysis is not part of routine toxicological analysis. This work aims to present two cases to illustrate the potential of entomological samples as complementary matrices to identify substances in cases of advanced putrefaction. (Case#1) A woman wasexhumed after 14 months to ascertain the exact cause of death. She died after six weeks of hospitalization because of intestinal ischemia followed by multiorgan failure. (Case#2) The corpse of a woman, known to have a psychiatric disorder, was discovered in her apartment. The state of decomposition of the body was consistent with a post-mortem period of several weeks (approximately 6 weeks). Toxicological investigations were performed in the biological and entomological samples of case#1 (hair, adipocere, brain, and pupae) and of case#2 (hair, bone, flies, and pupae) using liquid chromatography with high-resolution mass spectrometry and tandem mass spectrometry detection methods. In case#1, several drugs and metabolites were detected. In particular, the pupae analyses allowed the objectification of morphine administration, whereas morphine was only found in adipocere, but not in hair nor in brain. In case#2, the pupae analyses allowed the detection of three metabolites of quetiapine, and the flies analyses allowed the detection of valpromide, which was only detected in hair. In conclusion, the pupae and flies analyses in these two cases complemented the results obtained in the other alternative biological samples, which may guide hypotheses about the possible causes of death. Nevertheless, additional data and case reports would be of benefit to assess the value of entomotoxicology in routine forensic investigations.

Cannabinoid Stability in Postmortem Brain Samples Stored at Different Temperatures

Drug stability is an important concern of forensic toxicological testing, particularly postmortem (PM) samples that may be stored for an extensive period of time before analysis. In PM toxicology, the complex assessment of analyte stability in biological matrices can profoundly impact the interpretation of toxicological results and the outcome of forensic casework. The aim of this work is to assess the stability of ∆9-tetrahydrocannabinol (THC), cannabidiol, 11-hydroxy-THC (11-OH-THC), 11-nor-9-carboxy-∆9-THC (THCCOOH) and 11-nor-∆9-THC-9-carboxylic acid glucuronide (THCCOOH-glucuronide) in brain stored at three different temperatures (4°C, -20°C and -70°C) up to over 12 months (390 days) in order to establish the best storage condition for preventing potential drug degradation during the storage period. Brain is suitable and useful for xenobiotic concentrations and is a valuable specimen in the interpretation of PM toxicological results. In our study, pooled brain specimens were spiked at low and high concentrations to evaluate the change in concentration over time. Stable compounds were quantified within ±20% of the target concentration (the mean concentration resulting from the initial analysis). According to stability criteria, our preliminary findings revealed that all the cannabinoids studied are stable in frozen brain samples (-20°C and -70°C) for over 12 months: all the analytes' concentrations remained unaffected during storage over time, with the analytical variation staying within ±20%. On the contrary, under refrigeration conditions (4°C), 11-OH-THC, THCCOOH and THCCOOH-glucuronide were instable. Authentic brain samples, collected from eight cases during the autopsy, were analyzed, and the stability was evaluated. This study provided new data on cannabinoid stability in brain. The stability of the brain samples, both in spiked samples and in authentic caseworks, highlights the importance of the brain as a valid testing matrix when retesting is required after a long period of time or when laboratories are faced with backlog.

Analysis, Stability and Distribution of Pharmaceuticals and Drugs of Abuse over a Period of One Year in Formalin-Fixed Liver and Formalin Solutions

The present study reports a thorough research on the stability of drugs of abuse and pharmaceuticals over a time period of 12 months. Fixed-liver tissues and formalin solutions where the tissues were preserved were analyzed using an ultra high performance liquid chromatography--tandem mass spectrometry method that has been developed and validated for this purpose. The method monitors 84 drugs in a 13-minute run. The concentrations of the drugs found were compared with their concentrations determined in the fresh liver tissues in a previous study. In the study, 14 cases with forensic interest were included with the main objective of the analysis and the study of the stability and the distribution of drugs of abuse and pharmaceuticals in the human liver and the formalin solution during preservation. The results showed that the number of detected compounds in the first month was significantly lower than the compounds found in fresh tissues. The effect of formalin was catalytic, and few substances could be detected. Specifically, out of the 86 positive detections of the monitored substances in the fresh tissues (in which 25 different substances were found), only 32 (37%) remained detectable 3 months after, 20 (23%) 6 months after and 15 (17%) 12 months after.

Assessing the applicability of cerebrospinal fluid collected from the spinal cord for the determination of ethyl alcohol in post-mortem toxicology

This paper presents the results of a study on the applicability of cerebrospinal fluid (CSF) collected from the spinal canal in the post-mortem determination of ethyl alcohol. The present study reviewed data of autopsy cases (n = 45), in which ethyl alcohol was detected in CSF using gas chromatography with a flame ionization detector (HS-GC-FID), to investigate ethyl alcohol concentrations in CSF, compared with blood. As a result of statistical analysis of the obtained data, a high positive correlation was found between blood ethanol concentration and cerebrospinal fluid collected from the spinal canal ethanol concentration. The Pearson correlation coefficient was statistically highly significant (p < 0.001) (r = 0.9503). The data obtained allowed us to conclude that cerebrospinal fluid collected from the spinal canal can be collected during an autopsy as an alternative biological specimen to assess the ethanol content. Cerebrospinal fluid collected from the spinal canal can corroborate and lend credibility to the results obtained for blood and, in special cases, when blood is drawn from putrefied bodies and may even be a superior specimen to blood for assessing ethyl alcohol intoxication status.

Application of Teeth in Toxicological Analysis of Decomposed Cadavers Using a Carbamazepine-Administered Rat Model

In a regular autopsy, blood and organs are used to quantify drug and toxicant concentrations; however, specimens such as blood cannot be collected from highly decomposed corpses, making the quantification of drug and toxicants impossible. This study aimed to estimate the blood carbamazepine (CBZ) concentration from teeth, a part of the human body that is best preserved after death. We sampled teeth and blood of rats administered CBZ. The correlation between the tooth and serum CBZ concentrations was analyzed. Rats were euthanized after CBZ administration and kept at 22 °C for 0 to 15 days before sampling the teeth and measuring the CBZ concentration. Undecalcified, fresh, frozen sections of rat teeth were prepared, and CBZ localization was evaluated. CBZ concentrations in both teeth and cardiac blood peaked at 60 min after administration and increased in a dose-dependent manner. CBZ concentration in teeth did not substantially change after death, with high CBZ distribution being observed in the pulp cavity. The tooth and serum CBZ concentrations were highly correlated, suggesting that the measurement of toxicant concentration in sampled teeth would allow for the estimation of blood toxicant concentration in highly decomposed corpses.

Pharmacological data science perspective on fatal incidents of morphine treatment

Morphine prescribed for analgesia has caused drug-related deaths at an estimated incidence of 0.3% to 4%. Morphine has pharmacological properties that make it particularly difficult to assess the causality of morphine administration with a patient's death, such as its slow transfer between plasma and central nervous sites of action and the existence of the active metabolite morphine-6-glucuronide with opioid agonistic effects, Furthermore, there is no well-defined toxic dose or plasma/blood concentration for morphine. Dosing is often adjusted for adequate pain relief. Here, we summarize reported deaths associated with morphine therapy, including associated morphine exposure and modulating patient factors such as pharmacogenetics, concomitant medications, or comorbidities. In addition, we systematically analyzed published numerical information on the stability of concentrations of morphine and its relevant metabolites in biological samples collected postmortem. A medicolegal case is presented in which the causality of morphine administration with death was in dispute and pharmacokinetic modeling was applied to infer the administered dose. The results of this analytical review suggest that (i) inference from postmortem blood concentrations to the morphine dose administered has low validity and (ii) causality between a patient's death and the morphine dose administered remains a highly context-dependent and collaborative assessment among experts from different medical specialties.

Application of postmortem MRI for identification of medulla oblongata contusion as a cause of death: a case report

Whiplash injury is common in traffic accidents, and severe whiplash is characterized by cervical spinal cord injuries with cervical dislocation or fracture, that can be diagnosed by postmortem computed tomography (PMCT), postmortem magnetic resonance (PMMR), or conventional autopsy. However, for cervical spinal cord injury without fracture and dislocation, PMMR can be more informative because it provides higher resolution of soft tissues. We report the case of a 29-year-old male who died immediately following a traffic accident, in which the vehicle hit an obstacle at a high speed, causing deformation of the bumper and severe damage of the vehicle body. PMCT indicated no significant injuries or diseases related to death, but PMMR showed patchy abnormal signals in the medulla oblongata, and the lower edge of the cerebellar tonsil was herniated out of the foramen magnum. The subsequent pathological and histological results confirmed that death was caused by medulla oblongata contusion combined with cerebellar tonsillar herniation. Our description of this case of a rare but fatal whiplash injury in which there was no fracture or dislocation provides a better understanding of the potentially fatal consequences of cervical spinal cord whiplash injury without fracture or dislocation and of the underlying lethal mechanisms. Compared with PMCT, PMMR provides important diagnostic information in forensic practice for the identification of soft tissue injuries, and is therefore an important imaging modality for diagnosis of whiplash injury when there is no fracture or dislocation.

Randomly controlled drivers using minimally invasive sampling: assessment of drug prevalence in Western Switzerland over two time periods

BACKGROUND

According to the World Health Organization, road traffic injuries lead to 1.3 million deaths each year and represent the leading cause of death for young adults under 30 years old. The use of psychoactive substances, including alcohol, drugs and pharmaceuticals, is a well-known risk factor for road traffic injuries. Our study aims to assess the prevalence of substances consumed by drivers in western Switzerland. Such studies are pivotal to improving prevention and developing public awareness campaigns.

METHODS

To assess the prevalence of psychoactive substances among drivers, roadside controls were performed in collaboration with local police, using their classical sampling procedures to detect drivers under the influence of drugs or alcohol over two time periods (P1: 2006-2008, P2: 2017-2020). When impaired driving was not suspected by the police, minimally invasive sampling strategies (i.e., oral fluids during P1 and dried blood spots during P2) were performed on volunteer drivers after a road safety survey. A posteriori analyses and statistical interpretation were then performed.

RESULTS

Among the 1605 drivers included in the study, 1048 volunteers provided an oral fluid sample, while 299 provided a dried blood spot sample. The percentage of drivers testing positive for at least one substance that can impact driving abilities was stable over time, with a rate of 10.5% positivity measured over both periods. Considering the different categories of substances, a slight variation was observed between both periods, with 7.6 and 6.3% of pharmaceuticals and 3.6 and 4.9% of illicit drugs for P1 and P2, respectively. Regarding the consumption of illicit drugs, the highest percentage of positivity was measured in biological fluids of drivers under the age of 35, during nights and week-ends, periods which are considered particularly prone to fatal accidents for this age group. Disturbingly, the road safety survey highlighted that drivers' perception of the risk of getting positively controlled while driving after drug consumption is low (3.3 on a 1-to-10 scale, N = 299).

CONCLUSION

The number of positive cases measured in voluntary drivers who passed the preliminary police check demonstrates the importance of systematic biofluid sampling strategies regarding driving under the influence of psychoactive substances. Although the number of fatal road accidents globally has decreased over time, the results of this study reveal the need for both better prevention and deterrent processes that could potentially reduce the risk of fatal road accidents associated with drug consumption.

Attenuated total reflection-Fourier transform infrared spectroscopy: a universal analytical technique with promising applications in forensic analyses

Contemporary criminal investigations are based on the statements made by the victim and the eyewitnesses. They also rely on the physical evidences found in the crime scene. These evidences, and more particularly biological ones, have a great judicial value in the courtroom. They are usually used to revoke the suspect’s allegations and confirm or refute the statements made by the victim and the witnesses. Stains of body fluids are biological evidences highly sought by forensic investigators. In many criminal cases, the success of the investigation relies on the correct identification and classification of these stains. Therefore, the adoption of reliable and accurate forensic analytical methods seems to be of vital importance to attain this objective. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a modern and universal analytical technique capable of fingerprint recognition of the analyte using minimal amount of the test sample. The current systematic review aims to through light on the fundamentals of this technique and to illustrate its wide range of applications in forensic investigations. ATR-FTIR is a nondestructive technique which has demonstrated an exceptional efficiency in detecting, identifying and discriminating between stains of various types of body fluids usually encountered in crime scenes. The ATR-FTIR spectral data generated from bloodstains can be used to deduce a wealth of information related to the donor species, age, gender, and race. These data can also be exploited to discriminate between stains of different types of bloods including menstrual and peripheral bloods. In addition, ATR-FTIR has a great utility in the postmortem investigations. More particularly, in estimating the postmortem interval and diagnosing death caused by extreme weather conditions. It is also useful in diagnosing some ambiguous death causes such as fatal anaphylactic shock and diabetic ketoacidosis.

Post-Mortem Analysis of Heroin Biomarkers, Morphine and Codeine in Stomach Wall Tissue in Heroin-Related Deaths

Toxicological analysis of some cases can be complicated by poor sample quality caused by decomposition. Although heroin-related deaths have been researched extensively, the interpretation of toxicology findings in these cases is challenging, especially in instances where blood samples are unavailable. Thus, it is important to develop analytical methods for different sample types. In this study. a method for the quantification of 6-monoacetylmorphine, 6-acetylcodeine, morphine, and codeine in postmortem stomach wall tissue using liquid chromatography coupled with tandem mass spectrometry was developed and validated. All calibration curves prepared with the stomach wall tissue were linear and ranged from 0.5−1000 ng/g with determination coefficients of >0.99 and a lower limit of quantification of 1.0 ng/g. The coefficients of variation for within-run precision and between-run precision were <9%. Matrix effects of stomach wall tissues and their extraction recoveries were investigated and ranged from −19% to +17% and 76% to 80%, respectively. Among the 16 analyzed heroin-related death cases, 6-monoacetylmorphine, 6-acetylcodeine, morphine, and codeine were detected in 75%, 31%, 100%, and 94% of all stomach wall tissues with median concentrations of 90 ng/g, 20 ng/g, 140 ng/g, and 30 ng/g, respectively. This study provides new data on the distribution of 6-monoacetylmorphine, 6-Acetylcodeine, morphine, and codeine in postmortem stomach wall tissue and suggests the usefulness of alternative matrices for investigating heroin-related fatalities when blood samples are unavailable. In addition, the prevalence of 6-monoacetylmorphine in the stomach wall tissue was higher than that in the liver and kidney tissues.

A sustainable approach for the stability study of psychotropic substances using vitreous humor and liver as alternative matrices

The stability of psychotropic substances representing various drug groups important from the perspective of forensic chemistry, including benzodiazepines, antidepressants, carbamazepine, cocaine, and their selected metabolites, was investigated for 1 month in two alternative biological matrices, vitreous humor and liver homogenate. Three different thermal storage conditions (−20, 4, and 20 °C) were tested. Liquid chromatography-mass spectrometry (LC-MS) analysis was preceded by an effective solid-phase microextraction (SPME) procedure. The results were statistically analyzed using one-way ANOVA to find significant concentration variations over time. The results obtained allowed for dividing the analytes into four groups: stable under all tested conditions, only at −20 and 4 °C, only at 20 °C, and overall unstable. Nordiazepam, venlafaxine, and cocaine and its metabolites turned out to be the most unstable substances, while fluoxetine showed the highest storage stability in both matrices. The SPME/LC-MS method was comprehensively evaluated according to the principles of white analytical chemistry (WAC), which reconcile the greenness and functionality of the method. A close to 100% whiteness score proves its sustainability and suitability for the intended application.

Effects of postmortem interval, putrefaction, diabetes, and location of death on the analysis of ethyl glucuronide and ethyl sulfate as ethanol biomarkers of antemortem alcohol consumption

This study evaluated the forensic value of ethanol biomarkers ethyl glucuronide (EtG) and ethyl sulfate (EtS) under different conditions, including diabetes mellitus, drug abuse, and advanced decomposition. In addition, we explored whether ethanol, EtG, or EtS formation occurred in patients who died as a result of diabetes mellitus. Fifty-two routine postmortem cases were divided into three groups. Group 1 included only the post-mortem cases in which at least blood samples were available (n=47). Group 2 included all cases with positive BAC (n=28). Group 3 included the cases with negative BAC while information surrounding the cases suspected antemortem alcohol consumption and cases that tested negative for ethanol but positive for EtG and EtS. We analyzed multiple bodily fluid specimens, including the vitreous humor, for ethanol biomarker analysis and accurately identified antemortem ethanol consumption or postmortem ethanol synthesis. We also determined the utility of urine samples for analyzing ethanol and its metabolites in putrefaction cases. If no urine sample was available at autopsy due to urination before death or diabetes-associated glucosuria, vitreous humor samples were an appropriate alternative for ethanol biomarker testing. We observed postmortem ethanol synthesis in diabetic individuals even with a short postmortem interval (PMI), however, glucose did not increase postmortem ethanol production in individuals with diabetes under appropriate preservation. The shorter the PMI, the better the ethanol source can be determined. Postmortem ethanol production occurred in all body fluid specimens analyzed herein, including the vitreous humor. EtG and EtS levels were stable and provided accurate insight into ethanol sources, even in cases of postmortem ethanol production. While the present study focused on the use of vitreous humor for the analysis, it is expected such samples may not be available in cases of advanced decay. In cases where no other bodily fluid specimens are available, solid tissue specimens are highly preferred.

A Forensic Diagnostic Algorithm for Drug-Related Deaths: A Case Series

The best evidence provided in the literature worldwide suggests the importance of harmonizing the investigation in drug-related fatalities. In this study, the application of a multidisciplinary approach in eight cases of drug-related deaths is presented. Although death scene findings could be highly suggestive of drug intoxication, external examination and toxicological screening test alone are insufficient. There are several variables, and it is not always easy to give the proper interpretation of the drug detection. A complete autopsy is necessary to correctly complete organ and tissues sampling for further histological and toxicological studies and obtain body fluids. The use of peripheral blood is recommended to avoid artifacts. The collection of many specimens is warranted to get more responses. The sampling aims to provide a picture of the distribution of the substance in the body. The sample and the selection of the drugs and the matrices to investigate are case-dependent. The presented diagnostic algorithm provides the coroner with all the elements to investigate drug-related deaths and cooperate with toxicologists. Toxicological forensic diagnosis is still extremely heterogeneous in regional and national contexts. Funding for method development, research, networking, facilities, and technologies improvement is mandatory to standardize the toxicological investigation.

Comparison of Comprehensive Screening Results in Postmortem Blood and Brain Tissue by UHPLC-QTOF-MS

Alternative specimens collected during autopsies can be valuable in postmortem toxicology in cases where peripheral blood is not available. The applicability of brain tissue as an alternative matrix for drug screening by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was investigated in this study. Results of the 50 most frequently detected drugs and metabolites of toxicological interest in blood and brain tissue samples from 1,719 autopsy cases were compared. Examination of the results in paired blood and brain tissue samples revealed that the two matrices were in general comparable, as the majority of the 50 analytes were observed in a high number of the examined cases in both blood and brain tissue. This demonstrates the potential of brain tissue as an alternative matrix for drug screening in postmortem toxicology or as a secondary matrix for confirmation.

Distribution of tetrahydrocannabinol and cannabidiol in several different postmortem matrices

Cannabis is the most widely used illicit substance worldwide. A limited number of studies have investigated whether tetrahydrocannabinol (THC) and cannabidiol (CBD) can be detected in other postmortem matrices than blood and urine. The aim of this study was to investigate the distribution of THC and CBD in several different postmortem matrices. Concentrations in peripheral blood were compared to those in cardiac blood, pericardial fluid, psoas muscle, vastus lateralis muscle, and vitreous humor. A total of 39 postmortem forensic autopsy cases were included. THC and CBD were analyzed using gas chromatography-mass spectrometry. We were able to detect both THC and CBD in most of the analyzed matrices. For vitreous humor, however, only approximately 50% of the cases were available for analysis, and only two were found to be positive. Median concentrations in peripheral blood were 0.0040 (0.00042-0.056) mg/L for THC and 0.0013 (0-0.023) mg/L for CBD. The concentration ratios between pericardial fluid and cardiac blood compared to peripheral blood were< 1 for both THC and CBD for the majority of the cases. For THC, a median ratio of 0.60 (0.063-7.2) and 0.65 (0.068-4.8) were found for pericardial fluid and cardiac blood, respectively, compared to peripheral blood, whereas for CBD the corresponding median ratios were 0.40 (0.010-1.9) and 0.80 (0.017-2.4). The THC concentrations in psoas muscle and vastus lateralis muscle were high compared to those in peripheral blood in several cases, and large variations in the muscles to peripheral blood concentration ratios were seen. This was also the case for CBD. Our study shows that THC and CBD can be detected in postmortem matrices other than peripheral blood, and results from other matrices might provide important information in forensic cases where peripheral blood is not available. However, vitreous humor was not suitable for detecting neither THC nor CBD.

Postmortem redistribution of morphine in humans: Important variables that might be influencing the central blood/peripheral blood ratio

INTRODUCTION

In the field of forensic toxicology, many unexpected deaths are investigated as to whether toxicological substances may have caused or contributed to someone's death. One of the factors that makes interpretation of the results of quantitative analysis in postmortem toxicology challenging, is that measured postmortem drugs levels may vary according to the sampling site and the interval between death and specimen collection. These site- and time-dependent variations are caused by 'postmortem redistribution' (PMR). Literature shows that there are several factors that determine the degree of PMR, such as cell and tissue changes after death, decomposition and the physicochemical characteristics of drugs. Blood from peripheral sites seems to be less affected by PMR than cardiac blood. Therefore, the ratio of cardiac blood concentration/peripheral blood concentration (C/P) of a drug is often used as a marker of the extent of postmortem redistribution. In this study, we investigated the relationship between different potentially important variables and the C/P ratio of morphine in humans in order to provide new insights that might assist in the interpretation of quantitative results in forensic casework.

METHOD

Toxicological results of all morphine positive postmortem cases investigated by the Netherlands Forensic Institute between January 1, 2010 and July 31, 2020 were reviewed. Morphine was quantified in both femoral and cardiac blood in a total of 103 cases. The C/P ratios were determined for all selected cases. To collect data for this study, all corresponding files were reviewed. C/P ratios were compared between subgroups by performing either a Mann-Whitney U test or a Kruskal-Wallis test, followed by a post-hoc Mann-Whitney U test. Bonferroni correction was performed to correct for the likelihood of a significant result by chance due to multiple testing. After Bonferroni correction, a p-value< 0.004 was considered statistically significant.

RESULTS

The data suggests a relationship between grade of decomposition at autopsy, position of the corpse at discovery, route of administration, attempted resuscitation and the C/P ratio of morphine with p-values of 0.010, 0.026, 0.035 and 0.046, respectively.

CONCLUSION

Grade of decomposition at autopsy, position of the corpse at discovery, route of administration and attempted resuscitation seem to be influencing the C/P ratio of morphine. Of these four variables, the route of administration seems to have the greatest impact.

Unexpected results found in larvae samples from two postmortem forensic cases

Purpose

In forensics, entomological specimens can be used as additional/alternative matrices to detect xenobiotics when human specimens are limited in their application. Despite some advantages over implementing putrefied human remains, most medico-legal laboratories do not include entomotoxicological procedures as routine analytical methods. We thus applied two authentic cases to evaluate necrophagous larvae’s potential as complementary matrices for toxicological analysis after extensive postmortem decomposition.

Methods

Larvae and postmortem human samples, including hair, stomach contents, pericardial fluid, liver, lung, and skeletal muscle, were collected at autopsy. Samples were analyzed by liquid chromatography–tandem mass spectrometry and liquid chromatography–quadrupole time-of-flight mass spectrometry for pharmaceutical substances, illicit drugs, and new psychoactive substances, including synthetic cannabinoids, benzodiazepines, new synthetic opioids, and stimulants.

Results

Nearly all substances detected in human specimens, including several benzodiazepines and synthetic cannabinoids, were also detected in larvae. Surprisingly, some drugs, including the new psychoactive substances EAM-2201 and U-47700, were found exclusively in larvae and hair. The benzodiazepine etizolam was detected only in liver, lungs, and stomach contents, possibly resulting from characteristic tissue distribution in humans and/or larvae.

Conclusions

Antemortem external hair contamination with synthetic cannabinoids from side-stream smoke and postmortem hair contamination with substances in putrefaction fluids can be supposed in these cases. Our findings suggest that supplementary information can indeed be gained from analyzing larvae additional to those human specimens that are typically used for toxicological analysis after extensive postmortem decomposition. Nevertheless, these results represent merely two cases, requiring in-depth studies to determine whether such findings can identify acute intoxications as possible causes of death.

Homicidal poisoning series in a nursing home: retrospective toxicological investigations in bone marrow and hair

Homicidal poisonings remain rare and can be difficult to detect, especially in the elderly or in medical settings. In this atypical poisoning series, a young nursing assistant purposely poisoned thirteen residents of a nursing home and killed ten of them. The medications used were a mix of psychotropic medications (cyamemazine, loxapine, tiapride, risperidone, and mirtazapine), under liquid formulation, which were inducing malaise and coma. The forensic investigation included analysis of blood, urine, hair, and bone marrow and exhumations of seven corpses up to 3 years after the inhumation. Hair collected from a hairbrush of a cremated victim have been analyzed. Bone marrow sample preparation was based on a liquid/liquid triple extraction. Hair were incubated after decontamination overnight at 55 °C in methanol. Segmentation was possible for seven samples, except for delayed exhumation samples (n = 4) and hairbrush hair sample (n = 1). The extracts were then analyzed using gas chromatography coupled with mass spectrometry (GC-MS) for unknown screening and using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for a targeted screening and quantification. Screenings revealed the presence of the same mix of psychotropic medications. Cyamemazine, mirtazapine, loxapine, tiapride, and risperidone hair concentrations were 6-17,458 pg/mg, 74-1271 pg/mg, 9-1346 pg/mg, 13-148 pg/mg, and 3-5 pg/mg, respectively. Cyamemazine bone marrow concentrations were 229 and 681 ng/g and 152-717 ng/mL in blood. Patients' medications were also identified and quantified. This poisoning series provide analytical data that could support subsequent toxicological result interpretation in similar forensic cases.

Modeling microbial ethanol production by S. aureus, K. pneumoniae, and E. faecalis under aerobic/anaerobic conditions - applicability to laboratory cultures and real postmortem cases

A quite intriguing subject being intensively researched in the forensic toxicology field is the source of postmortem determined blood ethanol concentration: antemortem ingestion or postmortem microbial production. Our previous research on microbial ethanol production has reported a quantitative relationship between the ethanol and the higher alcohols and 1-butanol produced by Escherichia coli, Clostridium perfrigens, and Clostridium sporogenes. In this contribution, we continue our research reporting on the following: (i) the patterns of ethanol, higher alcohols, and 1-butanol production by the microbes Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (all being aerobic/facultative anaerobic species, common corpse's colonizers, and ethanol producers), under controlled laboratory conditions, (ii) the mathematical modeling, with simple mathematical equations, of the correlation between ethanol concentration and the other studied alcohols' concentrations, by performing multiple linear regression analysis of the results, and (iii) the applicability of the constructed models in microbial cultures developed under different temperature than that used to build the models, in denatured blood cultures and in real postmortem cases. The aforementioned alcohols were proved to be all indicators of ethanol production, both in qualitative and quantitative terms. 1-Propanol was the most significant alcohol in modeling microbial ethanol production, followed by methyl-butanol. The K. pneumoniae's models achieved the best scoring in applicability (E < 40%) compared to the S. aureus and E. faecalis models, both at laboratory microbial cultures at 37 °C and real postmortem cases. Overall, a noteworthy accuracy in estimating the microbial ethanol in cultures and autopsy blood is achieved by the employed simple linear models.

Cerebrospinal fluid in forensic toxicology: Current status and future perspectives

In forensic toxicology, alternative biological materials are very useful and important, e.g. in the case of lack of basic body fluids. One alternative biological material is cerebrospinal fluid (CSF). The procedures of the collection of biological material during the autopsy are performed in accordance with local, usually national recommendations, which most often require updating. It is very difficult to assess the possibility of using CSF as an alternative biological material for toxicological studies for the presence of drugs, intoxicants, including new psychoactive substances (commonly known as designer drugs), psychotropic substances, and ethyl alcohol, based on current data. Previous research suggests that CSF may be useful in toxicological studies, but these aspects need to be investigated more carefully because studies have collected CSF from different sites and often the results of different authors are not comparable. It would be necessary to prepare guidelines, e.g. the site of CSF collection that may influence the results of quantitative analysis. It would also be necessary to replicate some studies with a different collection site or a more recent analytical technique, e.g. for comparative testing of blood ethanol and cerebrospinal fluid. Cerebrospinal fluid can be a valuable information carrier in the absence of classic biological material from an autopsy. Investigating these aspects in more detail could allow the future use of this alternative material for routine toxicology analyzes in a forensic laboratory.

Drug detection in decomposed cadavers confirms testimonial evidence in a case of serial homicides

Toxicology investigation on human's buried dead bodies is a rare and challenging task in the forensic field. As requested by the Judicial Authority, this work aimed to verify testimonial evidence that emerged during a criminal investigation involving multiple murder cases. The statements indicated an improper medical administration of one or more alleged drugs (propofol, morphine, diazepam, and midazolam) which presumably caused the deaths. Since the supposed crimes took place several years before, the task of the present work was to obtain results to support the charges. The analyses involved 18 biological samples taken from four exhumed bodies, three of which were female and one male, each buried in a different date and mode. Each sample was treated with specific purification and extraction techniques (LLE - SPE) after the addition of the deuterated analogs of the searched analytes (propofol-d17, morphine-d3, diazepam-d5, midazolam-d4) as internal standards. Afterwards, the extracts were subjected to qualitative analysis by gas chromatography-mass spectrometry-Electron Impact (GC/MS - EI), both in full scan and SIM mode. Propofol, morphine, and diazepam were identified in the corpses. It supports testimonials that were administered just before the deaths occurred.

Dental Plaque Concentrations of Methadone, Morphine and Their Metabolites in Opioid Replacement Therapy and in Post-Mortem Cases

Non-mineralized dental biofilm (plaque) has potential as novel alternative matrix in forensic toxicology to prove drug use. The incorporation of illicit and medicinal drugs in dental plaque could take place through direct contact after oral or nasal intake, which can lead to high drug levels in the oral cavity, or indirectly via the secretion of drug-containing saliva, e.g. after intravenous application. Therefore, plaque samples from patients in opioid replacement therapy (ORT) and post-mortem plaque samples were analyzed and the drug concentrations were compared. The study comprised 26 plaque samples from ORT patients with different daily doses which were analyzed for methadone, morphine and their respective metabolites. Plaque samples were taken directly before the oral administration of the regular daily dose. Seventeen post-mortem plaque samples were analyzed, either from cases of lethal drug intoxications or after pain therapy with morphine. Plaque analysis was performed using LC-MS/MS after liquid extraction with acetonitrile. Plaque concentrations in ORT for methadone and its metabolite EDDP ranged from 42 to approx. 49,000 pg/mg (median 1,300 pg/mg) and from below 10 to 610 pg/mg (median 31 pg/mg), respectively. Morphine plaque concentrations in ORT ranged from 120 to 480 pg/mg (median 400 pg/mg). In lethal intoxication cases plaque concentrations were generally at least one order of magnitude higher than in the study groups with therapeutic substance use. This data will help to interpret drug findings in plaque. Additionally, the EDDP/methadone concentration ratio in plaque was lower after oral intake with contamination of the oral cavity (e.g. syrup) compared to cases with suspected intravenous application of methadone and could therefore indicate the drug administration route.

Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

Vitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3.

Graphic abstract

Methadone, Buprenorphine, Oxycodone, Fentanyl, and Tramadol in Multiple Postmortem Matrices

Peripheral blood (PB) concentrations are generally preferred for postmortem toxicological interpretation, but some autopsy cases may lack blood for sampling due to decomposition or large traumas, etc. In such cases, other tissues or bodily fluids must be sampled; however, limited information exists on postmortem concentrations in matrices other than blood. Pericardial fluid (PF), muscle and vitreous humor (VH) have been suggested as alternatives to blood, but only a few studies have investigated the detection of opioids in these matrices. In this study, we aimed to investigate the detection of methadone, buprenorphine, oxycodone, fentanyl and tramadol in postmortem samples of PF, skeletal muscle and VH, in addition to PB and cardiac blood and if drug concentrations in these alternative matrices were comparable to those in PB and thereby useful for interpretation. In most of the 54 included cases, only one opioid was detected. Methadone, oxycodone, fentanyl and tramadol were detected in all of the alternative matrices in almost all cases, while buprenorphine was detected less often. For methadone, the concentrations in the alternative matrices, except in VH, were relatively similar to those in PB. Larger variations in concentrations were found for buprenorphine, oxycodone and tramadol. Quantitative analyses appeared useful for fentanyl, in all of the alternative matrices, but only four cases were included. Toxicological analyses of opioids in these alternative postmortem matrices can be useful for detection, but quantitative results must be interpreted with caution.

Determination of drugs in exhumed liver and brain tissue after over 9 years of burial by liquid chromatography-tandem mass spectrometry-Part 2: Benzodiazepines, opioids, and further drugs

In this publication, benzodiazepines, opioids, and further drugs were analyzed in exhumed brain and liver tissue samples in 116 cases (total) after 9.5-16.5 years of burial. Solid phase extraction followed by liquid chromatography-tandem mass spectrometry was applied. Data from literature is listed summarizing the detectability of the presented analytes after a certain time of burial. In our study, 60% of the analyzed benzodiazepines, 100% of the opioids, and 82% of further drugs were detectable. Only the benzodiazepines lorazepam, nitrazepam, flunitrazepam, and its metabolite norflunitrazepam, and the drugs butylscopolamine, metronidazole, and omeprazole were not detectable at all. Percentage of positive findings (total, and separately for brain and liver tissue) and postmortem period are listed for each analyte. Correlation of detectability depending on postmortem period and condition of tissue are presented exemplarily for midazolam. No substantial correlation was observed. Despite a long time of burial, most benzodiazepines, opioids, and further drugs were detectable in the examined tissue samples. Our results may be a good support for future exhumations in which toxicological analyses are relevant.

Optimization of QuEChERS extraction for detection and quantification of 20 antidepressants in postmortem blood samples by LC-MS/MS

In this study, a comprehensively optimization of QuEChERS (quick, easy, cheap, effective, rugged and safe) method using design of experiments (DOE) was conducted to evaluate the best conditions to obtain the most effective extraction. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis was performed to identify and quantify the antidepressants, with electrospray ionization acquired in positive mode. The method was validated for all analytes; the calibration curves were linear from 10-1000ng/mL, with R²>0.98, and with LOD and LOQ defined as 10ng/mL. Method imprecision and bias were less than 14.3% and 18.9%, respectively. Neither carryover nor interferences were observed. Overall, the optimized method was applied in postmortem real sample analysis to quantify the antidepressants. This study showed a viable method that can be applied for routine forensic analysis, with a quick and easy sample preparation and a rapid total run time of 8min for each analysis.

Postmortem Liver and Kidney Tissue Concentrations of Heroin Biomarkers and Their Metabolites in Heroin-Related Fatalities*†

A method was developed and validated for analyzing 6-monoacetylmorphine, morphine, 6-acetylcodeine, and codeine in routine postmortem liver and kidney specimens using liquid chromatography-tandem mass spectrometry. Samples were prepared with a Stomacher instrument followed by solid-phase extraction. All calibration curves [0.5-1000 ng/g] were linear with coefficients of determination greater than 0.99 and limits of quantification of 1.0 ng/g. Within-run precision ranged between 2.0% and 8.0%, between-run precision ranged between 1.0% and 9.0%, and accuracy ranged between -5.0% and +3.0%. Matrix effects ranged from -18% to +9%. After matrix effects were excluded, analytical recoveries ranged from 76% to 94%. The distributions of 6-monoacetylmorphine, morphine, 6-acetylcodeine, and codeine were investigated in 31 postmortem cases in which heroin was the primary cause of death. In the current study, the median free morphine ratios were calculated for liver to blood and kidney to blood, which were 2.2 and 4.0, respectively. The current report highlights the importance of testing multiple specimens, including liver and kidney, in heroin-related deaths, especially if no blood samples are available. Furthermore, this work presents new information regarding the distribution of heroin metabolites in liver and kidney.

Determination of drugs in exhumed liver and brain tissue after over 9 years of burial by liquid chromatography-tandem mass spectrometry-Part 1: Cardiovascular drugs

This paper should serve as support for future exhumations in which an analysis of cardiovascular drugs is issued after over 9 years of burial. Amiodarone, amlodipine, atropine, bisoprolol, cafedrine, clonidine, esmolol, furosemide, hydrochlorothiazide, lisinopril, nifedipine, nitrendipine, phenprocoumon, torsemide verapamil, and xipamide were determined in liver and brain tissue of over 100 cases in which exhumation was performed after over 9 years of burial. Diagrams, showing the detectability depending on postmortem period as well as condition of tissues, are presented for furosemide.

The role of ethanol in fatalities in Jeddah, Saudi Arabia

In Saudi Arabia, alcohol consumption is prohibited by law, but interpreting postmortem ethanol can be complicated by its postmortem production. This study developed and validated a method using headspace gas chromatography with flame ionization detection and liquid chromatography tandem mass spectroscopy to detect ethanol and its polar metabolites (ethyl glucuronide [EtG] and ethyl sulfate [EtS]) in postmortem blood and urine specimens, respectively. All calibration curves were linear with coefficients of determination greater than 0.999. The limits of detection ranged 4.5-5.0mg/dL for ethanol and 0.05-0.06mg/L for EtG and EtS. The limits of quantification were 10.0mg/dL for ethanol and 0.075mg/L for EtG and EtS. Within-run precision was less than 11% for all analytes of interest. Matrix effects for EtG and EtS ranged 3-47%. After excluding matrix effects, analytical recoveries ranged 72-100%. This validated method was then used for routine postmortem forensic toxicology analyses in 592 routine postmortem cases to distinguish between antemortem ethanol consumption and its postmortem microbial formation. Among them, 98 blood samples (17%) were positive for ethanol or its polar metabolites. Thirty-two of these cases (33%) were positive for EtG and EtS and therefore due to antemortem ethanol consumption. The remaining 66 (67%) cases were negative for both EtG and EtS and therefore due to postmortem ethanol synthesis. Because this is the first study to report the problem of alcohol consumption in Saudi Arabia, further studies are essential for validating these findings.

Ethanol Determination in Post-Mortem Samples: Correlation between Blood and Vitreous Humor Concentration

Ethanol (ethylic alcohol) represents the most commonly used drug worldwide and is often involved in clinical and forensic toxicology. Based on several reports, excessive alcohol consumption is the main contributing factor in traffic accidents, drownings, suicides, and other crimes. For these reasons, it becomes essential to analyze the alcohol concentration during autopsy. Although blood is usually used for alcohol analysis in post-mortem cases, it could suffer alterations, putrefaction, and microbial contaminations. As an alternative to whole blood, vitreous humor has been successfully used in medico-legal studies. In this work, post-mortem specimens were analyzed for ethanol determination. The analysis of blood and vitreous humor were carried-out using gas chromatography-flame ionized detector (GC-FID) with a total run time of 6 min. The method was validated in terms of limit of detection, limit of quantification, dynamic range, sensibility, recovery, precision and trueness. A linear regression analysis indicated a coefficient of determination (R²) of 0.9981. The study confirmed no statistically differences between alcohol concentration in blood and vitreous humor, leading vitreous humor as an excellent matrix that could be used as an alternative to whole blood in toxicological analysis in cases where blood is not available.

The importance of sample size with regard to the robustness of postmortem reference values

Evaluating postmortem toxicological results is a challenging task due to multiple factors affecting blood concentrations after death. In order to improve the diagnostic accuracy in cases of suspected fatal intoxication different compilations of postmortem reference drug concentrations are often used. However, it is not clear what constitutes a reliable postmortem reference value. The current study presents reference concentrations for 13 substances from seven substance groups according to a standardized protocol. The reference concentrations were gathered from 3767 autopsy cases and subdivided into intoxications by one substance only (Group A, n=611), multi-substance intoxications (Group B, n=1355) and postmortem controls, in which incapacitation by drugs were excluded (Group C, n=1801). In particular, this study presents statistical information about the precision and conformity change with various sample sizes. Based on the present data >10 detections are usually needed, for the substances examined, to differentiate between intoxication cases and controls. Repeated samplings show that the median of small samples (N=≤5) has a high variation (normalized interquartile range 138-75%) and that a high number of detections (N=>20) in each group are needed to reduce the variation.

High Correlation between Ethanol Concentrations in Postmortem Femoral Blood and in Alternative Biological Specimens, but Large Uncertainty When the Linear Regression Model Was Used for Prediction in Individual Cases

In connection with medicolegal autopsies peripheral blood (e.g. from a femoral vein) is the specimen of choice for toxicological analysis, although alternative specimens are also sometimes submitted, such as bile, cerebrospinal fluid (CSF), vitreous humor (VH), bladder urine, pleural effusions and/or lung fluid. Ethanol concentrations were determined in duplicate in femoral blood and in various alternative biological specimens by headspace gas chromatography. The analysis was carried out on two different fused silica capillary columns furnishing different retention times for ethanol and both n-propanol and t-butanol were used as internal standards. The results were evaluated by linear regression using blood alcohol concentration (BAC) as dependent or outcome variable and the concentrations in an alternative specimen as independent or predictor variable. The Pearson correlation coefficients were all statistically highly significant (P &lt; 0.001); r = 0.94 (bile), r = 0.98 (CSF), r = 0.97 (VH), r = 0.92 (urine), r = 0.94 (lung fluid) and r = 0.96 (pleural cavity effusions). When the regression model was used to predict femoral BAC from the mean concentration in an alternative specimen the mean and 95% prediction intervals were 1.12 ± 0.824 g/L (bile), 1.41 ± 0.546 g/L (CSF), 1.15 ± 0.42 g/L (VH), 1.29 ± 0.780 g/L (urine), 1.25 ± 0.772 g/L (lung fluid) and 0.68 ± 0.564 g/L (pleural cavity effusions). This large uncertainty for a single new observation needs to be considered when alcohol-related deaths are evaluated and interpreted. However, the analysis of alternative specimens is recommended in medical examiner cases to provide supporting evidence with regard to the origin of ethanol, whether this reflects antemortem (AM) ingestion or postmortem (PM) synthesis.