Multi target analysis of putrefactive specimens by liquid chromatography-tandem mass spectrometry to prove multiple poisonings by hypnotics and muscle relaxants

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.

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.

A fast liquid chromatography-tandem mass spectrometry method for determining benzodiazepines and analogues in urine. Validation and application to real cases of forensic interest

A fast liquid chromatographic/tandem mass spectrometric method was developed for the simultaneous determination in human urine of seventeen benzodiazepines, four relevant metabolites together plus zolpidem and zopiclone. The sample preparation, optimized to take into account the matrix effect, was based on enzymatic hydrolysis and liquid-liquid extraction. The separation of the twenty-three analytes was achieved in less than eight minutes. The whole methodology was fully validated according to UNI EN ISO/IEC 17025:2005 rules and 2006 SOFT/AAFS guidelines. Selectivity, linearity range, identification (LOD) and quantitation (LOQ) limits, precision, accuracy and recovery were evaluated. For all the species the signal/concentration linearity was satisfactory in the 50-1000 ng/mL concentration range. The limits of detection ranged from 0.5 to 30 ng/mL and LOQs from 1.7 to 100.0 ng/mL. Precisions were in the ranges 5.0-11.8%, 1.5-11.0% and 1.1-4.4% for low (100 ng/mL), medium (300 ng/mL) and high (1000 ng/mL) concentration, respectively. The accuracy, expressed as bias% was within ± 25 % for all the analytes. The recovery values, evaluated at 300 ng/mL concentration, ranged from 56.2% to 98.8%. The present method for the determination of several benzodiazepines, zolpidem and zopiclone in human urine proved to be simple, fast, specific and sensitive. The quantification by LC-MS/MS was successfully applied to 329 forensic cases among driving re-licensing, car accidents and alleged sexual violence cases.