Validation of a fully automated solid-phase extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry method for quantification of 30 pharmaceuticals and metabolites in post-mortem blood and brain samples

Toxicological profile using mass spectrometry in sudden cardiac arrest survivors admitted to a tertiary centre

BACKGROUND

There has been no previous thorough toxicological examination of a cohort of patients with resuscitated sudden cardiac arrest. We aimed to determine the qualitative and quantitative drug composition in a resuscitated sudden cardiac arrest population, using forensic toxicology, with focus on prescribed, non-prescribed, and commonly abused drugs.

METHODS

Individuals aged 18-90 years with resuscitated sudden cardiac arrest of presumed cardiac causes were prospectively included from a single tertiary center. Data from the sudden cardiac arrest hospitalization was collected from medical reports. Drugs used during resuscitation or before the blood sampling were identified and excluded in each patient. Mass spectrometry-based toxicology was performed to determine the absence or presence of most drugs and to quantify the findings.

RESULTS

Among 186 consecutively enrolled resuscitated sudden cardiac arrest patients (median age 62 years, 83% male), 90% had a shockable rhythm, and were primarily caused by ischemic heart disease (66%). In total, 90 different drugs (excluding metabolites) were identified, and 82% of patients had at least one drug detected (median of 2 detected drugs (IQR:1-4)) (polypharmacy). Commonly abused drugs were present in 16%, and QT-prolonging drugs were present in 12%. Polypharmacy (≥5drugs) were found in 19% of patients. Importantly, none had potentially lethal concentrations of any drugs.

CONCLUSION

In resuscitated sudden cardiac arrest patients with cardiac arrest of presumed cardiac cause, routine toxicological screening provides limited extra information. However, the role of polypharmacy in sudden cardiac arrest requires further investigation. No occult overdose-related cardiac arrests were identified.

Automated enzymatic hydrolysis of urine samples for improved systematic toxicological analysis of drug-facilitated sexual assault cases

Drug-facilitated sexual assault (DFSA) is characterized by victim incapacitation due to intoxicating substances. Detection of single drug exposure from DFSA requires a systematic toxicological analysis strategy including sensitive methods covering a broad spectrum of substances. The aim of this study was to develop and validate an UHPLC-MS/MS screening method for analysis of samples from DFSA cases and incorporate an automated enzymatic pre-treatment of urine samples into a robotic sample preparation for an efficient laboratory workflow. The screening method included 144 drugs of abuse, pharmaceuticals, and metabolites relevant to DFSA. The use of a recombinant enzyme showed an efficient glucuronide hydrolysis with an average parent drug recovery of 97%. Investigation of matrix effect showed no pronounced ion enhancement or suppression for most analytes (96%), and extraction recovery was above 80% for 97% of analytes. Process efficiency ranged from 50% to 138% for most analytes. The LODs ranged from 0.0001 mg/L to 2 mg/L depending on analyte, and most analytes met the SOFT recommended minimum performance limits. The validated method was applied to authentic suspected DFSA cases (n = 38). Results showed that drugs of abuse, benzodiazepines, and antidepressants were most commonly found in suspected DFSA cases. Incorporation of an automated enzymatic hydrolysis step during sample preparation enables a fast and simple workflow for simultaneous analysis of blood and urine samples for an improved systematic toxicological analysis strategy for DFSA cases.

Uncovering forensic evidence of drug-facilitated sexual assault: Toxicological findings from Eastern Denmark from 2015-2022

In drug-facilitated sexual assault (DFSA), the victim is unable to provide consent or resists sexual activity due to substance intoxication by voluntary or covert consumption. Obtaining forensic evidence of the assault is challenged by rapid drug metabolism and late sample collection. The objective of this study was to present toxicological findings and associated demographics from police reported sexual assault cases in Eastern Denmark from 2015 to 2022. A total of 369 sexual assault cases were submitted for analysis and a subgroup of 268 cases were categorized as suspected DFSA cases. The majority of the total sexual assault victims were women at the age 15-25 and the perpetrators were often unknown or an acquaintance. Time from assault to sample collection was slightly longer for suspected DFSA cases (12-24 h) compared to non-DFSA (<12 h). Positive toxicology was observed in 86 % of cases and the most common drug groups included alcohol (45 %), drugs of abuse (38 %), antidepressants (14 %), antihistamines (12 %), and benzodiazepines (11 %). Hypnotics were detected to a smaller extent (7 %). A total of 77 drugs were detected and the most commonly observed were cocaine, tetrahydrocannabinol (THC), cetirizine, amphetamine, diazepam and sertraline. The high level of observed alcohol and drugs of abuse indicated that most DFSA cases in Eastern Denmark were of an opportunistic approach rather than proactive.

Detection of scopolamine in urine and hair in a drug-facilitated sexual assault

The use of the drug scopolamine in drug-facilitated crimes is known. Nevertheless, given the high potency of the drug and its rapid metabolism, analysis in blood and urine may not be sufficient for drug detection in late crime declaration, especially following a single-dose administration in drug-facilitated sexual assault (DFSA) cases. Hair may constitute an essential supplemental matrix extending the drug detection window in such cases. This case report presents quantitative data on scopolamine findings in urine and hair in a DFSA case. A young female had consumed several alcoholic drinks at a party venue when her behaviour became noticeably peculiar. Later, she woke up next to an unknown man and had no recollection of the night's events. Blood and urine samples were collected 18 h after the incident. The initial toxicological target screening using UHPLC-TOF-MS detected scopolamine in the hydrolysed urine sample, and quantification yielded 41 µg/L scopolamine in urine, while blood was negative. Segmental hair analysis using multitarget UHPLC-MS/MS was performed on three washed 2-cm segments of hair collected five weeks after the incident, yielding 0.37 pg/mg scopolamine only in the relevant hair segment. This case report provides novel insight into the concentration in hair following a single exposure of scopolamine and the feasibility of detecting scopolamine in hair by comparison to published toxicological findings.

Strategies for automating analytical and bioanalytical laboratories

Analytical measurement methods are used in different areas of production and quality control, diagnostics, environmental monitoring, or in research applications. If direct inline or online measurement methods are not possible, the samples taken have to be processed offline in the manual laboratory. Automated processes are increasingly being used to enhance throughput and improve the quality of results. In contrast to bioscreening, the degree of automation in (bio)analytical laboratories is still low. This is due in particular to the complexity of the processes, the required process conditions, and the complex matrices of the samples. The requirements of the process to be automated itself and numerous other parameters influence the selection of a suitable automation concept. Different automation strategies can be used to automate (bio)analytical processes. Classically, liquid handler-based systems are used. For more complex processes, systems with central robots are used to transport samples and labware. With the development of new collaborative robots, there will also be the possibility of distributed automation systems in the future, which will enable even more flexible automation and use of all subsystems. The complexity of the systems increases with the complexity of the processes to be automated.

Comparative Study of Postmortem Concentrations of Benzodiazepines and Z-Hypnotics in Several Different Matrices

Benzodiazepines and z-hypnotics are detected in the majority of fatal overdose cases in Norway, often in combination with other drugs of abuse, and their concentrations in peripheral blood (PB) might be important to elucidate the cause of death. In some forensic autopsies, PB is however not available. The aim of the present study was to compare concentrations of benzodiazepines and z-hypnotics in five alternative matrices to assess whether these concentrations are comparable to concentrations in PB. A total of 109 forensic autopsy cases were included. PB, cardiac blood (CB), pericardial fluid (PF), psoas muscle (PM), lateral vastus muscle (LVM) and vitreous humor (VH) from each case were analyzed using ultra high performance liquid chromatography--tandem mass spectrometry. We were able to detect clonazepam, 7-aminoclonazepam, flunitrazepam, 7-aminoflunitrazepam, nitrazepam, 7-aminonitrazepam, diazepam, nordiazepam, oxazepam, alprazolam, midazolam, zopiclone and zolpidem in all the analyzed matrices. Concentrations measured in VH were generally much lower than those of PB for all compounds except zopiclone. 7-Amino metabolite concentrations were high compared to the parent compounds, although less so for the muscle samples. Concentrations of the parent nitrobenzodiazepines in muscles were higher than those in PB, but for the other compounds, concentrations in muscle showed good correspondence with PB. Both CB and PF were viable alternative matrices for PB, although a larger variation and a tendency for higher concentrations in PF were observed. This study shows that CB, PM, LVM and PF can give comparable concentrations to PB for benzodiazepines and z-hypnotics, while VH was less suitable. The concentrations in alternative matrices must, however, be interpreted carefully.

Development of two fully automated quick, easy, cheap, effective, rugged, and safe pretreatment methods for the extraction of psychotropic drugs from whole blood samples

Quick, easy, cheap, effective, rugged, and safe extraction strategies are becoming increasingly adopted in various analytical fields to determine drugs in biological specimens. In the present study, we developed two fully automated quick, easy, cheap, effective, rugged, and safe extraction methods based on acetonitrile salting-out assisted liquid-liquid extraction (method 1) and acetonitrile salting-out assisted liquid-liquid extraction followed by dispersive solid-phase extraction (method 2) using a commercially available automated liquid-liquid extraction system. We applied these methods to the extraction of 14 psychotropic drugs (11 benzodiazepines and carbamazepine, quetiapine, and zolpidem) from whole blood samples. Both methods prior to liquid chromatography-tandem mass spectrometry analysis exhibited high linearity of calibration curves (correlation coefficients, > 0.9997), ppt level detection sensitivities, and satisfactory precisions (< 8.6% relative standard deviation), accuracies (within ± 16% relative error), and matrix effects (81-111%). Method 1 provided higher recovery rates (80-91%) than method 2 (72-86%), whereas method 2 provided higher detection sensitivities (limits of detection, 0.003-0.094 ng/mL) than method 1 (0.025-0.47 ng/mL) owing to the effectiveness of its dispersive solid-phase extraction cleanup step. These fully automated extraction methods realize reliable, labor-saving, user-friendly, and hygienic extraction of target analytes from whole blood samples.

Suitability of cardiac blood, brain tissue, and muscle tissue as alternative matrices for toxicological evaluation in postmortem cases

Drug concentrations in peripheral blood are often used to evaluate whether death was caused by drug intoxication. In some cases, peripheral blood is not available, and analytical results of alternative matrices should instead be used in the toxicological evaluation. However, reference concentrations of alternative matrices are few, which makes interpretation of results a challenge. In this study, concentrations of selected benzodiazepines, opioids, illicit drugs, and other commonly used drugs in postmortem femoral blood, cardiac blood, brain tissue, and muscle tissue are presented. Alternative matrix-to-femoral blood drug concentration ratios and correlations of blood and alternative matrix drug concentrations were calculated to examine which of the investigated alternative matrices were most suited to use for toxicological evaluation in cases where peripheral blood is not available. The results showed that concentrations in cardiac blood, brain tissue, and muscle tissue could be useful in the postmortem evaluation of most of the 19 selected analytes. In most cases, analytes were detected in all the alternative matrices. The median concentration ratios for the selected analytes in brain tissue, cardiac blood, and muscle tissue relative to femoral blood ranged from 0.57 to 3.42, 0.59 to 1.87, and 0.67 to 7.04, respectively. Overall, cardiac blood provided the concentrations most comparable with femoral blood concentrations, indicating that cardiac blood can be useful in cases where femoral blood is not available. However, the measured concentrations should be interpreted with caution.

Recent developments in sample preparation techniques combined with high-performance liquid chromatography: A critical review

This review article compares and contrasts sample preparation techniques coupled with high-performance liquid chromatography (HPLC) and describes applications developed in biomedical, forensics, and environmental/industrial hygiene in the last two decades. The proper sample preparation technique can offer valued data for a targeted application when coupled to HPLC and a suitable detector. Improvements in sample preparation techniques in the last two decades have resulted in efficient extraction, cleanup, and preconcentration in a single step, thus providing a pathway to tackle complex matrix applications. Applications such as biological therapeutics, proteomics, lipidomics, metabolomics, environmental/industrial hygiene, forensics, glycan cleanup, etc., have been significantly enhanced due to improved sample preparation techniques. This review looks at the early sample preparation techniques. Further, it describes eight sample preparation technique coupled to HPLC that has gained prominence in the last two decades. They are (1) solid-phase extraction (SPE), (2) liquid-liquid extraction (LLE), (3) gel permeation chromatography (GPC), (4) Quick Easy Cheap Effective Rugged, Safe (QuEChERS), (5) solid-phase microextraction (SPME), (6) ultrasonic-assisted solvent extraction (UASE), and (7) microwave-assisted solvent extraction (MWASE). SPE, LLE, GPC, QuEChERS, and SPME can be used offline and online with HPLC. UASE and MWASE can be used offline with HPLC but have also been combined with the online automated techniques of SPE, LLE, GPC, or QuEChERS for targeted analysis. Three application areas of biomedical, forensics, and environmental/industrial hygiene are reviewed for the eight sample preparation techniques. Three hundred and twenty references on the eight sample preparation techniques published over the last two decades (2001-2021) are provided. Other older references were included to illustrate the historical development of sample preparation techniques.

Simple implementation of muscle tissue into routine workflow of blood analysis in forensic cases - A validated method for quantification of 29 drugs in postmortem blood and muscle samples by UHPLC-MS/MS

Whole blood is most often the matrix of choice for postmortem analysis but it is not always available. In these cases, muscle tissue can be used as an alternative matrix. Therefore, an ultra-high-performance liquid chromatography-tandem mass spectrometry method for the quantification of 29 drugs and metabolites of toxicological interest in postmortem muscle tissue was developed and validated. Additionally, a validation of whole blood was carried out to compare the results from the two matrices. Solid-phase extraction was performed by an automated robotic system to minimize manual labour and risk of human errors, and increase robustness, sample throughput and sample traceability. The method was validated in terms of selectivity, matrix effect, extraction recovery, process efficiency, measuring range, lower limit of quantification, carry-over, stability, precision and accuracy. To correct for any inter-individual variability in matrix effects on analyte accuracy and precision, deuterated analogues of each analyte were used as internal standards. The lower limit of quantification in both blood and muscle homogenate ranged between 0.002 and 0.005 mg/kg, while the upper limit of quantification spanned from 0.20 to 1.0 mg/kg. Corrected with the 4-fold dilution factor, the corresponding concentrations in muscle tissue were 0.008-0.02 mg/kg at the lower limit of quantification and 0.80-4.0 mg/kg at the upper limit of quantification. The method showed acceptable precision and accuracy, with precision below 12% and accuracies ranging from 87% to 115% at up to 6 levels for all analytes in both matrices. In addition, comparison between calibration standards in spiked muscle homogenate and spiked blood showed that analyte concentrations in muscle samples could be quantified by using spiked blood samples as calibration standards with acceptable precision and accuracy when using deuterated analogues as internal standards. The investigation of matrix effects showed no great difference between blood and homogenates of non-decomposed and decomposed muscle tissue for most analytes. In the samples where high ion suppression or enhancement was observed, the results were corrected by the internal standards. Statistical comparison of quality control samples in blood and muscle tissue showed no obvious differences, and therefore muscle tissue was included in the routine method for analysis of blood samples and used in autopsy cases where no blood was available. By adding a semi-automated homogenization step before the remaining automated sample preparation, muscle tissue samples were easily incorporated into the workflow of the existing routine method. The present method has been successfully implemented in routine analysis of blood and muscle tissue since 2019.

Postmortem Brain-Blood Ratios of Codeine, Fentanyl, Oxycodone and Tramadol

The analgesics, codeine, fentanyl, oxycodone and tramadol, frequently occur in postmortem cases and determining their role in the cause of death can be challenging. However, postmortem blood is susceptible to redistribution and may not be available in cases of severe blood loss, putrefaction or burns. Brain tissue may serve as a viable supplement to blood or on its own, as it is resistant to postmortem redistribution and often available as a sample matrix when blood is not available. We present brain and blood concentrations and brain-blood ratios of the four analgesics from 210 autopsy cases. The cases were classified according to the presumed cause of death: A: The compound was believed to have solely caused a fatal intoxication. B: The compound was assumed to have contributed to a fatal outcome in combination with other drugs, alcohol or disease. C: The compound was not regarded as being related to the cause of death. Blood and brain samples were prepared by automatic solid phase extraction and quantified by liquid chromatography-mass spectrometry. The squared correlation coefficients between concentrations in brain tissue and blood ranged 0.45-0.91. The median brain-blood ratios were codeine 1.8 (range 0.47-4.6), fentanyl 2.1 (range 0.29-16), oxycodone 1.8 (range 0.11-6.0) and tramadol 1.8 (range 0.047-6.8). A significantly higher brain-blood ratio of codeine was observed in cases where heroin had been administered, although there was a wide overlap. Intravenous and transdermal fentanyl administration could not be distinguished based on the blood or brain concentration or the brain-blood ratio. The results of this study may benefit the toxicological investigation in postmortem cases where one of the four analgesics are suspected of having contributed to or caused a fatal intoxication.

Ketamine analogues: Comparative toxicokinetic in vitro-in vivo extrapolation and quantification of 2-fluorodeschloroketamine in forensic blood and hair samples

Recently, the new psychoactive substance (NPS) ketamine analogue 2-fluoro-deschloroketamine (2FDCK) was observed in driving-under-the-influence-of-drugs whole blood samples and in a forensic hair investigation case in Denmark. The molecular structure variations among the NPS subgroups may alter the metabolic fate and drug potency, thereby posing a threat for drug users. This study reports quantification of 2FDCK in whole blood samples and forensic hair and compares the following toxicokinetic parameters: unbound fraction (f_u) and in vitro-in vivo-extrapolation (IVIVE) of hepatic clearance for ketamine, norketamine, 2FDCK, methoxetamine and deschloroketamine. The f_u was investigated with ultrafiltration, while clearance studies were conducted at 1 μM with pooled human liver microsomes. Samples were analysed by liquid chromatography and mass spectrometry. For the first time, 2FDCK was determined in a concentration range between 0.005 and 0.48 mg/kg in blood samples. Segmental hair analysis demonstrated 2FDCK at concentrations from 0.007 to 0.034 ng/mg throughout the three investigated segments. Toxicokinetic comparison of the five compounds gave a f_u between 0.54 and 0.84, with ketamine being the most bound and deschloroketamine being the least bound, in accordance with the logP of the compounds. Conversely, a negative correlation was observed between the molecular weight of the halogen in the ortho-position and IVIVE hepatic clearance. The IVIVE of hepatic clearance, CL_{parallel-tube}, gave values from 18.1 to 5.44 mL/min/kg for ketamine and methoxetamine, respectively. The deschloroketamine IVIVE was disregarded due to low drug elimination under the experimental conditions used. This study provides a basis for toxicokinetic understanding of ketamine analogues.

Interpreting γ-hydroxybutyrate concentrations for clinical and forensic purposes

INTRODUCTION

γ-Hydroxybutyric acid is an endogenous substance, a therapeutic agent, and a recreational drug of abuse. This psychoactive substance acts as a depressant of the central nervous system and is commonly encountered in clinical and forensic practice, including impaired drivers, poisoned patients, and drug-related intoxication deaths.

OBJECTIVE

The aim of this review is to assist clinical and forensic practitioners with the interpretation of γ-hydroxybutyric acid concentrations in blood, urine, and alternative biological specimens from living and deceased persons.

METHODS

The information sources used to prepare this review were PubMed, Scopus, and Web-of-Science. These databases were searched using keywords γ-hydroxybutyrate (GHB), blood, urine, alternative specimens, non-conventional biological matrices, saliva, oral fluid, sweat, hair, vitreous humor (VH), brain, cerebrospinal fluid (CSF), dried blood spots (DBS), breast milk, and various combinations thereof. The resulting 4228 references were screened to exclude duplicates, which left 1980 articles for further consideration. These publications were carefully evaluated by taking into account the main aims of the review and 143 scientific papers were considered relevant. Analytical methods: The analytical methods used to determine γ-hydroxybutyric acid in blood and other biological specimens make use of gas- or liquid-chromatography coupled to mass spectrometry. These hyphenated techniques are accurate, precise, and specific for their intended purposes and the lower limit of quantitation in blood and other specimens is 0.5 mg/L or less. Human pharmacokinetics: GHB is rapidly absorbed from the gut and distributes into the total body water compartment. Only a small fraction of the dose (1-2%) is excreted unchanged in the urine. The plasma elimination half-life of γ-hydroxybutyric acid is short, being only about 0.5-0.9 h, which requires timely sampling of blood and other biological specimens for clinical and forensic analysis. Endogenous concentrations of GHB in blood: GHB is both an endogenous metabolite and a drug of abuse, which complicates interpretation of the laboratory results of analysis. Moreover, the concentrations of GHB in blood and other specimens tend to increase after sampling, especially in autopsy cases. This requires the use of practical "cut-off" concentrations to avoid reporting false positive results. These cut-offs are different for different biological specimen types. Concentrations of GHB in clinical and forensic practice: As a recreational drug GHB is predominantly used by young males (94%) with a mean age of 27.1 years. The mean (median) and range of concentrations in blood from apprehended drivers was 90 mg/L (82 mg/L) and 8-600 mg/L, respectively. The concentration distributions in blood taken from living and deceased persons overlapped, although the mean (median) and range of concentrations were higher in intoxication deaths; 640 mg/L (280 mg/L) and 30-9200 mg/L, respectively. Analysis of GHB in alternative specimens: All biological fluids and tissue containing water are suitable for the analysis of GHB. Examples of alternative specimens discussed in this review are CSF, saliva, hair strands, breast milk, DBS, VH, and brain tissue.

CONCLUSIONS

Body fluids for the analysis of GHB must be obtained as quickly as possible after a poisoned patient is admitted to hospital or after a person is arrested for a drug-related crime to enhance chances of detecting the drug. The sampling of urine lengthens the window of detection by 3-4 h compared with blood samples, but with longer delays between last intake of GHB and obtaining specimens, hair strands, and/or nails might be the only option. In postmortem toxicology, the concentrations of drugs tend to be more stable in bladder urine, VH, and CSF compared with blood, because these sampling sites are protected from the spread of bacteria from the gut. Accordingly, the relationship between blood and urine concentrations of GHB furnishes useful information when drug intoxication deaths are investigated.

Postmortem analysis of three methoxyacetylfentanyl-related deaths in Denmark and in vitro metabolite profiling in pooled human hepatocytes

Methoxyacetylfentanyl belongs to the group of fentanyl analogues and has been associated with several deaths in recent years. We present three case reports of deceased individuals that tested positive for methoxyacetylfentanyl consumption, as well as in vitro and in vivo metabolite profiles. Methoxyacetylfentanyl was quantified by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in femoral blood, as well as in urine and brain tissue when these were available. Metabolite profiling was performed by incubating methoxyacetylfentanyl with pooled human hepatocytes (pHH) in Leibovitz's L-15 medium supplemented with fetal bovine serum. Metabolites were identified in vivo and in vitro using UHPLC-high resolution (HR)-MS/MS. The measured methoxyacetylfentanyl concentration was 0.022-0.056mg/kg (N=3) in femoral blood, 0.12mg/kg (N=1) in urine, and 0.074mg/kg (N=1) in brain tissue homogenate. A total of 10 metabolites were identified. The observed metabolic pathways were: hydroxylation(s), N-dealkylation, O-demethylation, deamination, glucuronidation, and combinations thereof. Major analytical targets in vitro and across measured biological samples in vivo were methoxyacetylfentanyl, the O-demethyl- metabolite, and the deamide-metabolite. Intoxication with methoxyacetylfentanyl was judged as the cause of death or a major contributing factor in all three presented cases.