Journal of analytical toxicology最新文献

Cannabis consumption has and continues to increase dramatically, as does its legalization for recreational and/or medicinal use at the state, but not at the federal level. The increased consumption and legalization have spurred significant cannabis focused research, with particular interest in defining the pharmacokinetic characteristics of this complex natural product. Supporting this research requires a bioanalytical method that accurately and simultaneously quantifies the primary cannabinoids and their metabolites. The objective of this method validation was to meet pre-specified sensitivity targets (0.5 ng/mL for most analytes) from a low sample volume (0.2 mL) and single extraction approach that could quantify Δ9-tetrahydrocannabinol, cannabidiol, and their metabolites. Moreover, we sought to rigorously characterize the stability of included cannabinoid analytes, both in solution and plasma. The developed assay required optimization of extraction and mobile phase solvents, as well as mass transitions to achieve the selectivity required to meet the desired sensitivity targets. Stability experiments indicated solution stability of no more than 6 months when stored in polypropylene at -30 or -80 °C and ∼3 years (34.5 months) of plasma stability when stored in polypropylene at -80 °C. The assay was successfully applied to ∼1650 samples without a batch failure. This validated LC-MS/MS assay provides unique information on cannabinoid stability and has been utilized to generate novel data on the pharmacokinetics of cannabis constituents and their metabolites.

This document describes updates to previously published recommendations for drug testing in drug-impaired driving cases. A survey of drug testing practices in driving under the influence of drug (DUID) and motor vehicle fatality cases was sent to toxicology laboratories across the United States and Canada. Following compilation of survey data, a virtual consensus meeting was held where forensic science practitioners and the authors reviewed the survey results and conducted a comprehensive review of the 2021 recommendations using a modified Delphi method. Tier I and Tier II screening and confirmation scope and cutoffs were re-evaluated to update the recommendations. Carisoprodol and meprobamate were moved to the Tier II scope from Tier I; gabapentin was promoted to the Tier I scope from Tier II; screening cutoffs were differentiated for immunoassay versus non-immunoassay (e.g. chromatographic) screening for blood and oral fluid; cross-reactivity screening requirements were removed and clarified with specific cutoff values; several cutoffs for screening and confirmation were increased or removed for blood and oral fluid; urine was removed as a recommended matrix for testing in cases involving suspected drug impairment.

The interpretation of urine drug test results is complicated by the potential for poppy seed ingestion to yield opiate concentrations above standard cutoffs. U.S. federally regulated workplace drug testing programs have adjusted thresholds over time to mitigate this confounder, but the introduction of low cutoffs in clinical settings has reintroduced interpretive challenges. Fifteen adult participants consumed, ad libitum, a portion of a poppy seed kolachi. Urine samples were collected over five days and analyzed for codeine and morphine. Detection windows were evaluated across cutoffs ranging from 4,000 ng/mL to the assays' limits of detection (8 ng/mL codeine; 10 ng/mL morphine). Opiate detection duration was inversely related to cutoff. At the 4,000 ng/mL cutoff, eight participants were codeine-positive at 8 hours, with two participants remaining positive at 24 hours. At this cutoff, a single participant was morphine-positive through the first 12 hours. At 2,000 ng/mL, only codeine remained detectable, in a single participant, at 48 hours. At 300 ng/mL, seven participants were opiate-positive at 48 hours (only codeine, n = 4; only morphine, n = 2; codeine and morphine, n = 1), and four remained positive at 72 hours (only codeine, n = 2; only morphine, n = 2). At 50 ng/mL, five participants were opiate-positive at 96 hours (only codeine, n = 2; only morphine, n = 2; codeine and morphine, n = 1). Four participants continued to produce detectable opiate concentrations at 108 hours (codeine only, n = 1; morphine only, n = 1; codeine and morphine, n = 2). A single ingestion of a commercial poppy seed kolachi produced urinary opiate concentrations exceeding cutoffs from 4,000 ng/mL down to the assays' limits of detection, with positivity persisting up to 108 hours. These findings underscore the need for cautious interpretation of positive results-especially in settings using low cutoffs-and support the potential utility of adjunctive markers such as thebaine.

XXXXX recently added brain to its fentanyl analog testing method for 14 analogs (fluoroisobutyryl fentanyl, acetyl fentanyl, acryl fentanyl, alfentanil, butyryl fentanyl, carfentanil, fentanyl, para-fluorofentanyl, furanyl fentanyl, methoxyacetyl fentanyl, norcarfentanil, norfentanyl, sufentanil, and valeryl fentanyl) and 3 U-series drugs (U-47700, U-48800, and U-49900). Brain is a protected and isolated organ with lower metabolic activity than other tissues, which can assist in interpreting results and preserving parent drug. Limited publications testing brain samples for fentanyl and fentanyl analogs exist and none describe homogenate stability for these analytes. Validation of the solid phase extraction and liquid chromatography tandem mass spectrometry method followed the ASB 036 Standard Practices for Method Validation in Forensic Toxicology and included limit of detection, limit of quantification, calibration model, bias and precision, ionization suppression/enhancement, interferences, carryover, processed sample stability, and dilution integrity. Carfentanil, fentanyl, furanyl fentanyl and methoxyacetyl fentanyl) met quantitative bias and precision acceptance criteria in brain. To assess homogenate stability, brain homogenates (both unpreserved and preserved with 1% sodium fluoride) were fortified with 50 ng/mL of analyte, stored at room temperature (∼20 °C), refrigerated (2-8 °C), or frozen (∼-20 °C), and analyzed in triplicate over a 90-day period. Analytes were considered stable if analyte/internal standard response ratio was within ± 20% of Day 0 and chromatographic peaks met qualitative acceptance criteria. Frozen brain homogenates could be stored for up to 90 days and withstood three freeze/thaw cycles for acetyl fentanyl, alfentanil, fentanyl, para-fluorofentanyl, FIBF, methoxyacetyl fentanyl, and norfentanyl. Brain homogenate stability was improved when frozen and was not impacted by the addition of 1% sodium fluoride. The study herein provides insight into the feasibility of testing brain for fentanyl analogs and their stability under various storage conditions, contributing valuable data to the limited literature on brain toxicology testing.

Free phenol and cresol isomers in human samples have drawn interest, particularly in the field of forensic toxicology. In this study, a simultaneous analytical method for the detection of unchanged phenol and three structural isomers of cresol in human blood was developed using GC-MS/MS. This method was applied to authentic human heart and peripheral vein blood samples obtained from a fatal intoxication case involving accidental exposure to liquified phenol containing cresol isomers. In addition, we applied the method to blood samples from 110 healthy individuals. The QuEChERS method was employed for extracting the target compounds, followed by centrifugation. The supernatant of the organic layer was then evaporated by dry nitrogen flow. After the residue was derivatized with 30 μL of BSTFA reagent, the final reconstituted eluate was analyzed by GC-MS/MS. Quantification was performed using the internal standard method for o-cresol and m-cresol, and the standard addition method for phenol and p-cresol. All validation parameters met acceptable criteria. The concentrations of phenol, o-cresol, m-cresol, and p-cresol in heart blood were 335.27, 1.70, 25.27, and 14.21 μg/mL, respectively; in venous blood, the concentrations were 71.43, 1.25, 13.57 and 5.99 μg/mL, respectively. The 95% upper medical reference values (UMRVs) for free phenol and p-cresol in blood from 110 healthy individuals were <0.0865 μg/mL and <0.142 μg/mL, respectively. These data are valuable for evaluating exposure and determining cause of death in forensic investigations.

Background: Alcohol biomarkers including ethyl glucuronide (EtG) and phosphatidylethanol (PEth) are ordered frequently in clinical and forensic settings including solid organ transplantation. PEth provides a long detection window but can be insensitive to light drinking. In contrast, EtG and ethyl sulfate (EtS) can be elevated after light alcohol consumption and might complement PEth testing.

Methods: Urine EtG/EtS and whole blood PEth results were evaluated from all clinically-ordered testing between 2014-2024. PEth and EtG/EtS confirmation were performed by liquid chromatography tandem mass spectrometry at two reference laboratories, using cutoffs: Lab A, PEth 20 ng/mL, EtG and EtS 500 and 250 ng/mL; Lab B, PEth 10 ng/mL, EtG and EtS 250 and 100 ng/mL. Only Lab B performed EtG screening by immunoassay, using a 500 ng/mL cutoff.

Results: PEth was positive in 1269 (15.6%) of 8131 samples, compared to 769 (6.7%) confirmed EtG/EtS positives from 11555 samples. EtG screening (n = 9668) was positive in 743 (7.7%) samples, of which 30 (4.0%) confirmed negative (false positives); the screen was indeterminate in 267 (2.8%) samples, 66 of which confirmed positive and 172 negative. Of 3132 paired PEth and EtG samples, 2887 (92.2%) were concordant, 224 (7.2%) were PEth-positive and 21 (0.7%) were EtG-positive. PEth was significantly more sensitive in paired samples (p < 0.001), even after accounting for potential confounders. Limiting testing to PEth would have correctly identified alcohol consumption in 331 of 373 (88.7%) instances versus EtG/EtS in 149 (39.9%), and reduced charges by >$720,000 USD.

Discussion: PEth outperformed EtG/EtS in detecting alcohol consumption in a predominantly abstinent transplant population. Compared to PEth, EtG/EtS had lower overall positivity and poorer sensitivity in paired samples; additionally, EtG screening demonstrated false positives and indeterminate results. EtG testing provided little added value beyond PEth in this population, and did not warrant the increased cost of performing both tests.

In recent years, nitrite (salt) overdose has become a method of suicide worldwide. This study presents the development and validation of a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for the quantification of nitrite and nitrate in postmortem whole blood. Nitrate measurements were performed after precipitation, filtration and liquid-liquid extraction. Potassium ferricyanide was used to stabilize nitrite and prevent degradation processes, while the Griess reaction allowed sensitive nitrite quantification. In eleven cases of suspected sodium nitrite intoxication, nitrite concentrations ranged from 1.0-529 µg/mL in femoral blood and 1.3-176 µg/mL in heart blood, while nitrate concentrations ranged from 57-997 µg/mL and 54-907 µg/mL, respectively. Physiological nitrate concentrations of max. 72 µg/mL were determined in postmortem blood (n = 5), whereas physiological nitrite levels were not detectable (LOD/LOQ: 1 µg/mL). Significant inter-case variability was observed in nitrate and nitrite levels, reflecting the influence of individual postmortem biochemistry, condition and presumably thanatomicrobial profile and activity, while intra-case discrepancies between femoral and heart blood highlight the importance of analyzing multiple matrices. Nevertheless, an intoxication with sodium nitrite was either concluded if: I) Nitrite was detected (10/11)or II) High nitrate concentrations (above physiological level) were measured (1/11). The interpretation of cases was supported by toxicological data like methemoglobin levels, circumstantial evidence and morphological findings such as grey skin coloration and chocolate-brown colored blood. The findings enhance the understanding of highly variable nitrate and nitrite dynamics in postmortem toxicology and provide practical insights for forensic investigations, emphasizing the integration of analytical methods, circumstantial and morphological evidence.

On-site drug screening of oral fluid samples has gained attention because of its convenience and rapid results. The aim of this investigation was to compare the results of preliminary screening for drugs in oral fluid samples collected from suspected drug-impaired drivers using DrugWipe 6S and WipeAlyser reader with the results obtained from blood samples. Additionally, we compared the DrugWipe test results with findings of drug traces detected within the used DrugWipe devices. Police officers selected a sample of 355 suspected drug-impaired drivers in 2023. They used DrugWipe 6S for preliminary drug screening of drivers. After the field drug testing of oral fluid, the apprehended drivers were brought to a physician for the collection of blood samples. The collected samples (DrugWipe devices and blood samples) were submitted to the Norwegian National Forensic Toxicology Laboratory for analysis. The proportion of positive DrugWipe results that were unconfirmed when analysing blood samples was 82% for opiates, 75% for cocaine, and ∼19%-20% for amphetamines, cannabis, and benzodiazepines. The proportion of negative DrugWipe results that were found positive in blood samples was for cannabis and benzodiazepines ∼13%-14%, and for other drugs <3%. Detected drug traces in the used DrugWipe devices corresponded well with DrugWipe readouts for cannabis, amphetamines, and cocaine. The lack of correspondence between DrugWipe test results for cocaine and findings in blood may be due to the fact that the concentration of cocaine in saliva is often much higher than in blood, and the DrugWipe test is very sensitive. In addition, degradation and elimination of cocaine before the blood sample is taken may contribute to cocaine concentrations below the cut-off concentration in blood. For opiates and benzodiazepines, traces of drugs were found in relatively few DrugWipe devices. Many unconfirmed positives for opiates were most likely due to cross-reaction with substances in 'snus' (snuff tobacco).

Δ9-Tetrahydrocannabinol (Δ9-THC) is the most prominent and main psychoactive cannabinoid found in cannabis. In forensic matters involving cannabis, such as drugged driving or workplace accident investigations, blood Δ9-THC determination is typically required. Venipuncture by a phlebotomist at a medical facility is often the standard blood collection protocol, but this procedure is time consuming and requires specialized training. Capillary blood collection at the site of a transportation or workplace mishap may provide a collection method that is logistically easier and may better reflect blood cannabinoid concentrations at the time of an incident. This study represents the first temporal comparison of the concentration of Δ9-THC and its primary metabolites in venous and capillary blood obtained from users following ad libitum inhalation of contemporary high-concentration cannabis products. Participants provided their own cannabis from a licensed Colorado dispensary and were instructed to smoke or vape ad libitum the amount most used for the desired effect during a 15-minute period. Capillary blood samples collected at the lateral shoulder using the TAP® II microneedle device and standard venipuncture samples at the forearm were collected contemporaneously at baseline and then 10, 30, 60, 90, and 140 minutes after the last inhalation and were analyzed for Δ9-THC, 11-hydroxy-Δ9-THC, and 11-carboxy-Δ9-THC by liquid chromatography-tandem mass spectrometry. Within-subject Δ9-THC concentrations trended lower, often up to 30 to 40%, in contemporaneous capillary blood samples than in venous blood samples until 140 min after cannabis smoking. Concentrations of the Δ9-THC metabolites 11-hydroxy-Δ9-THC and 11-carboxy-Δ9-THC were equivalent at all but the first timepoint after smoking. Due to logistical advantages, capillary blood collection by microneedle devices may be a viable option for qualitative detection of Δ9-THC and its metabolites soon after an incident or a quantitative determination if the samples are collected at least 2 hours after cannabis inhalation.

Herbicide poisoning commonly involves both paraquat and diquat (DQ); DQ poisoning alone is less frequently reported, and especially rare in Japan. We present a case of fatal DQ poisoning after attempted suicide by ingesting DQ dibromide, requiring intensive care including haemodialysis (HD). Toxicological profiles of DQ, DQ metabolites, and bromide ion in serum were investigated relative to the course of treatment. Quantitative analyses were carried out by liquid chromatography/tandem mass spectrometry (LC-MS-MS) for DQ and its oxidative metabolites and by capillary electrophoresis for bromide (Br-). The quantitated initial serum DQ concentration prior to HD#1 was 75 μg/mL. Following HD#1, DQ concentration dropped to 8.4 μg/mL but re-elevated about 12 hours later (12 μg/mL). HD#2 lowered the DQ concentration to 1.5 μg/mL but again re-elevated prior to death (2.8 μg/mL). Serum Br- concentration pre-HD#1 was 493 μg/mL and dropped to 27-49 μg/mL after HD treatment. While HD treatment seemed to have reduced the DQ concentration significantly, re-elevation of the serum DQ level suggests that it was a temporary relief not enough to prevent the patient from going into multiple organ failure. Possibility of bromism was also investigated, as the ingested herbicide contained 33% DQ dibromide, thus Br- would have also been absorbed into the body along with DQ.