Journal Of Analytical Toxicology[JOURNAL]
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200 papers
Theory put into practice: probabilistic approach to propranolol as the cause of death.
Kriikku P, Vauhkonen P, Ojanperä I … +1 more , Oura P
J Anal Toxicol · 2026 Jul · PMID 42402213 · Publisher ↗
Post-mortem forensic toxicology aims to assist in cause-of-death investigations, especially in suspected toxicity cases. Utilizing a large toxicology database derived from routine medico-legal autopsies, we tested a prob...
Post-mortem forensic toxicology aims to assist in cause-of-death investigations, especially in suspected toxicity cases. Utilizing a large toxicology database derived from routine medico-legal autopsies, we tested a probabilistic approach in assessing the contribution of a toxicological finding to the underlying cause of death. In this retrospective study, theoretical general prior odds for a poisoning death were calculated for three different groups of cases based on the laboratory referral issued by the forensic pathologist. The groups were, in descending order according to the likelihood of poisoning: A) suspected poisoning (N = 6356), B) exclusion of poisoning (N = 12 641), and C) for background information only (N = 15 018). Propranolol was selected as a model compound with 548 propranolol-positive cases in the database. First, the detected propranolol concentrations were divided into concentration ranges. Then, a likelihood ratio (LR) for each concentration range was calculated as the probability of observing a propranolol concentration within a certain concentration range given that propranolol poisoning was the cause of death, divided by the probability of observing a propranolol concentration within the same concentration range given that propranolol poisoning was not the cause of death. To showcase the practical applicability, posterior odds for fatal propranolol poisoning were derived using the odds form of Bayes' theorem (posterior odds = prior odds x LR) for a selection of propranolol-positive cases (N = 5) and compared with the cause of death recorded on the death certificate. In our dataset, the point estimate for LR exceeded 1 for propranolol concentrations ≥ 1.0 mg/L. The LR proved useful in assisting in the cause-of-death determination and making the interpretive process more systematic and transparent. Despite some limitations, this study added to the evidence of the usefulness of a probabilistic approach in assessing the relevance of a toxicology finding in autopsy cases.
Is drug facilitated sexual assault changing? About a case involving 4-bromomethcathinone.
Thomas S, Romain M, Hilary M … +3 more , Jérôme L, Pascal H, Laurence L
J Anal Toxicol · 2026 Jul · PMID 42384933 · Publisher ↗
Drug facilitating sexual assault (DFSA) corresponds to sexual activity occurring whereas the victim is unable to express consent due to the action of drug. Although use of sedative and amnesic drug in DFSA such as benzod...
Drug facilitating sexual assault (DFSA) corresponds to sexual activity occurring whereas the victim is unable to express consent due to the action of drug. Although use of sedative and amnesic drug in DFSA such as benzodiazepines and gamma-hydroxybutyrate (GHB) is widely described in the medical literature, there is a lack of information regarding the involvement of amphetamine derivatives in this context, particularly synthetic cathinones. Herein, we report a case of a 19-year-old woman who presents herself into the emergency department following an acute alcoholic intoxication and a suspected DFSA after going in a nightclub. The emergency toxicological screening on the plasma and urine of the patient, performed through liquid chromatography coupled to high resolution tandem mass spectrometry (LC-HRMS) on target and non-target mode and with gas chromatography coupled to high resolution mass spectrometry (GC-HRMS) enabled the detection of 4-bromomethcathinone (4-BMC), a new psychoactive substance (NPS) of the cathinone family. The demethylated and reduced metabolites of the drug were also found in both plasma and urine. No other substance was identified except ethanol which was quantified in gas chromatography-flame ionization detection (GC-FID) and diazepam with its metabolites, this last one having been administrated in the emergency department. As far as we know, this report described the first case of DFSA involving this halogenated derivative of cathinone and consequently, highlights the need for toxicologists to systematically investigate with specific analytical methods the potential presence of NPS in case of DFSA.
Differentiation of 2-, 3-, and 4-Fluorofuranylfentanyl Using HPLC-MS and Human Liver Microsomes.
Iwaki T, Oida Y, Morikawa M … +8 more , Itoh K, Iwai K, Abe K, Kohyama E, Ito T, Tanaka H, Yokoi T, Kitaichi K
J Anal Toxicol · 2026 Jun · PMID 42377259 · Publisher ↗
The structural similarity of positional isomers of fentanyl analogs makes their forensic differentiation difficult, particularly when the parent compounds exhibit similar chromatographic behavior and product-ion spectra....
The structural similarity of positional isomers of fentanyl analogs makes their forensic differentiation difficult, particularly when the parent compounds exhibit similar chromatographic behavior and product-ion spectra. This study evaluated the differentiation of 2-, 3- and 4-fluorofuranylfentanyl (2-, 3- and 4-FFF) using high-performance liquid chromatography-mass spectrometry (HPLC-MS) and human liver microsomes (HLMs). The synthesized positional isomers were analyzed using gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and HPLC-ion trap-time-of-flight mass spectrometry (HPLC-IT-TOF-MS). Although the parent isomers were separated by GC-MS, their retention times and product-ion spectra obtained by HPLC-MS/MS were highly similar under the present conditions. Incubation with HLMs supplemented with NADPH, UDPGA and alamethicin produced three Phase I metabolic categories: an oxidative N-dealkylated metabolite of FFF (M1), monohydroxylated FFF metabolites (M2a and M2b), and an amide hydrolysis product of FFF (M3). Glucuronide conjugates were not detected under the present analytical conditions. Although M1 was the predominant metabolite, M1 did not retain the complete FFF structure. M2a and M2b were putatively assigned as monohydroxylated metabolites that retained the complete FFF structure, and may therefore support the differentiation of FFF positional isomers, although their retention times did not allow the differentiation. M3, which did not retain the complete FFF structure, showed distinct retention times among the three positional isomers, providing chromatographic information useful for metabolite-based differentiation. The in vitro elimination half-lives differed among 2-, 3- and 4-FFF under the present HLM conditions, suggesting possible differences in the pharmacokinetic properties of these positional isomers. These findings indicate that HPLC-MS analysis using HLMs provides useful analytical information for differentiating FFF positional isomers.
Trends and Circumstances of Pediatric Fentanyl Deaths in North Carolina: A 10-year Retrospective Study.
Welch M, Friederich LW, Cox ME … +2 more , Aurelius MB, Bishop-Freeman SC
J Anal Toxicol · 2026 Jun · PMID 42366685 · Publisher ↗
This study describes the contextual factors and scientific data associated with fentanyl-related deaths among individuals aged 0-17 years in North Carolina. Using information from the North Carolina Medical Examiner Syst...
This study describes the contextual factors and scientific data associated with fentanyl-related deaths among individuals aged 0-17 years in North Carolina. Using information from the North Carolina Medical Examiner System from 2015-2024, 138 pediatric fentanyl deaths were identified. Manually abstracted scene information, toxicology results, and pathological findings allowed for a rarely examined in-depth analysis of circumstances surrounding these deaths. Children less than two years (n = 33, 1.38 per 100,000) and adolescents aged 15-17 years (n = 80, 1.96 per 100,000) experienced a fentanyl-related death rate higher than the statewide pediatric fentanyl-related death rate of 0.60 per 100,000 residents. Among children less than two years, 78.8% of overdose onset occurred in the decedent's primary residence, and drugs or paraphernalia were present at the scene in 51.5% of cases. Co-sleeping was documented in 60.6% of deaths, with 80.0% occurring in adult beds. Postmortem blood concentrations of fentanyl among children less than two years ranged from less than 0.50 to 280 ng/mL (mean 27.0 ng/mL, median 17 ng/mL). Among adolescents, 62.5% of overdose onset occurred in the decedent's primary residence, followed by a friend's residence (13.8%). History of substance use was documented in 82.5% of cases and drugs or paraphernalia were present in 67.5% of cases. Blood concentrations of fentanyl among adolescents ranged from less than 1.0 to 330 ng/mL (mean 21.7 ng/mL, median 11.0 ng/mL). Scene investigation and documentation allow for the recognition of behavioral trends which can be targeted for age-specific overdose prevention strategies. Among decedents less than two years, notable trends included children co-sleeping in adult beds with access to drugs and drug waste and/or prolonged periods without supervision. Among older adolescents, several cases involved suspected counterfeit pharmaceuticals and/or periods of non-contact with primary caregivers. Improved workflows for pediatric medicolegal death investigation and electronic reporting strategies are already underway.
Drug Detection in Traffic-Related Fatalities in Connecticut (2020-2024).
Mohr ALA, Gill JR, Logan BK
J Anal Toxicol · 2026 Jun · PMID 42366678 · Publisher ↗
Motor vehicle fatalities continue to be a leading cause of preventable death in the United States. Beginning in 2019, there was a steady uptick in traffic fatalities nationally, which peaked in 2021. The state of Connect...
Motor vehicle fatalities continue to be a leading cause of preventable death in the United States. Beginning in 2019, there was a steady uptick in traffic fatalities nationally, which peaked in 2021. The state of Connecticut has experienced similar trends with increases in traffic fatalities over the last several years. The focus of this review was to evaluate drug positivity in traffic-related fatalities that occurred in Connecticut between January 1, 2020 and December 31, 2024. Cases related to traffic fatalities were identified by the state's Office of the Chief Medical Examiner. Deaths of drivers, passengers, and pedestrians were used for the data set. A total of 1,816 fatal motor vehicle incidents were reviewed. Of these, 312 cases lacked toxicology results, and five cases had testing canceled; both were excluded from substance-related analyses. Among the remaining 1,499 cases with available toxicological data, 1,084 (72%) had at least one positive toxicology finding. Drug positivity was identified in 75% (713 of 948) of driver fatalities, 66% (125 of 188) of passenger fatalities, and 67% (221 of 327) of pedestrian fatalities. The most frequently encountered drugs across all three classes of decedents were ethanol, delta-9 tetrahydrocannabinol, and fentanyl. These findings underscore the pervasive role of drugs and alcohol across all categories of traffic-related deaths and highlight the ongoing need for preventive strategies, toxicology testing, and targeted public safety interventions.
Characterization of postmortem γ-hydroxybutyric acid (GHB) and a novel model to discern exogenous use.
Pearring S, Tchu S, Desharnais B … +4 more , Doyon A, Mireault P, Elliott S, Rodda LN
J Anal Toxicol · 2026 Jun · PMID 42345529 · Publisher ↗
Interpretation of postmortem (PM) γ-hydroxybutyric acid (GHB) remains challenging due to endogenous production and PM increases in concentration associated with decomposition. Existing interpretation guidelines primarily...
Interpretation of postmortem (PM) γ-hydroxybutyric acid (GHB) remains challenging due to endogenous production and PM increases in concentration associated with decomposition. Existing interpretation guidelines primarily rely on a single criterion, such as concentration thresholds or urine-to-blood ratios. In San Francisco, routine and unbiased implementation of GHB testing across all casework generated a large dataset including 1865 GHB detections in PM blood or urine, of which 552 were paired peripheral blood and urine samples. Cases were categorized as acute exogenous use, confirmed exogenous use, or no indication of use based on toxicological and investigative findings. Peripheral blood concentrations in cases with no indication of use did not vary significantly by age, gender, race, or manner of death but were significantly higher in decomposed cases. While existing guidelines effectively identify endogenous levels, the proposed hybrid model, combining peripheral blood concentration (B) with urine-to-blood ratio (U/B), enables further classification into no exogenous use, possible exogenous use (B > 5 mg/L and U/B > -0.05 × B + 4), and acute exogenous use (B > 50 mg/L and U/B > -0.05 × B + 10). The model was evaluated and compared to existing guidelines. Internal applicability was assessed using recent casework, and external applicability was evaluated using an independent dataset from Québec, Canada. The hybrid model demonstrated improved performance, achieving substantially higher positive predictive value when compared to existing guidelines, while maintaining equal or improved performance measures across other metrics. This approach provides a conservative, evidence-based framework for distinguishing acute exogenous GHB use in PM casework.
Development and validation of a quantitative analytical method for urine samples in drug-facilitated sexual assault cases.
Denkena IL, Martins AF, Rodrigues LC … +7 more , Lanaro R, de Azevedo RCS, Santos MGG, Muñoz D, Gianvecchio VAP, Huestis MA, Costa JL
J Anal Toxicol · 2026 Jun · PMID 42340679 · Publisher ↗
Drug-facilitated sexual assault (DFSA) is a type of drug-facilitated crime defined as a form of sexual violence against an individual incapacitated or unconscious due to the effects of psychoactive substances. These subs...
Drug-facilitated sexual assault (DFSA) is a type of drug-facilitated crime defined as a form of sexual violence against an individual incapacitated or unconscious due to the effects of psychoactive substances. These substances alter the victim's level of consciousness, judgment, and/or memory. This study aimed to develop and validate a quantitative LC-MS/MS method for psychoactive substances and biotransformation products with detection limits suitable for DFSA investigations. The scope was based on ANSI/ASB Standard 121 guidelines (2021). Urine samples were submitted to enzymatic hydrolysis, followed by liquid-liquid extraction. An aliquot of urine underwent protein precipitation with acetonitrile. After agitation, centrifugation, and evaporation of solvent, samples were resuspended with mobile phase and injected into LC-MS/MS system. The method was validated according to ANSI/ASB Standard 036 recommendations, with quantification limits of 0.5 to 50 ng/mL and linearity of 0.5 to 750 ng/mL. Bias and imprecision were better than 14.3% and 14.8%, respectively, and matrix effect ranging from -72.9% to 21.5%. No evidence of carryover and interference was observed. All substances were stable at 10 °C for 24 hours and recovery results were better than 5.2%. In total, 42 samples from sexual assault victims were analyzed, with at least one substance detected in 26 samples. Ethanol was the most predominant substance, followed by 11-nor-9-carboxy-Δ-9-tetrahydrocannabinol and cocaine. A sensitive method was developed and validated to quantify psychoactive substances in urine, with low limits of detection and quantification, adequate linearity, bias, imprecision, and successfully applied to the analysis of authentic urine samples.
Evaluation of a rapid immunoenzymatic screening kit (SAMElife™) for drugs of abuse detection in hair.
Martini V, Ortu S, Stramesi C … +2 more , Vignali C, Morini L
J Anal Toxicol · 2026 Jun · PMID 42316794 · Publisher ↗
The performance of the SAMElife™ rapid hair screening kit was evaluated for the detection of drugs of abuse in 31 anonymized hair samples, encompassing 217 analyses for morphine, cocaine, amphetamines, buprenorphine, oxy...
The performance of the SAMElife™ rapid hair screening kit was evaluated for the detection of drugs of abuse in 31 anonymized hair samples, encompassing 217 analyses for morphine, cocaine, amphetamines, buprenorphine, oxycodone, fentanyl, and methadone. Screening results were compared with confirmatory gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. The kit demonstrated high specificity (100%) and good sensitivity (81.8%) for basic drugs, with four false negatives observed for cocaine, while no false positives were recorded. Detection of Δ9-tetrahydrocannabinol (THC) was unreliable, yielding uniformly positive results regardless of confirmatory analysis. The automated workflow, requiring only hair cutting and no prior decontamination, provides a rapid and practical approach for preliminary screening in routine toxicology laboratories. Despite limitations in THC detection and the small number of positive samples for some analytes, the SAMElife™ kit offers a reliable tool to reduce the number of samples requiring confirmatory analysis. Further evaluation on larger populations and optimization of the THC assay are recommended.
Performance evaluation of a commercial LC-high-resolution-MS platform for untargeted whole blood analysis: comparison with immunoassay and LC-low-resolution-MS urine screening and targeted LC-MS/MS whole blood quantification.
Bovens A, Brockbals L, Kraemer T … +1 more , Steuer AE
J Anal Toxicol · 2026 Jun · PMID 42302757 · Publisher ↗
In forensic toxicology (FT), drug of abuse (DoA) screening is essential yet challenging. This study presents a vendor-based, high-resolution (HR) LC-MS/MS blood screening method implemented without in‑house optimization,...
In forensic toxicology (FT), drug of abuse (DoA) screening is essential yet challenging. This study presents a vendor-based, high-resolution (HR) LC-MS/MS blood screening method implemented without in‑house optimization, in comparison to immunoassay-based and low-resolution (LR) urine screening approaches simultaneous to (semi)quantification. The HR-method allows detection of more than 3000 analytes, including DoAs, drugs and suspected new psychoactive substances (NPS). Following protein precipitation, analytes qualitatively identified in 500 authentic whole-blood samples using the HR-method were qualitatively compared with results from the immunoassay and LR urine screening. Additionally, 82 common DoAs and drugs were (semi)quantitatively validated according to ANSI and GTFCh guidelines and quantitative performance was assessed against a fully validated targeted LC-MS/MS method (MRM mode). In total, the HR-method detected 819 (83%) of the 994 analytes identified by the LR urine screening. Substances not captured by the HR approach typically showed concentrations below the identification limit and/or were of negligible relevance in FT. The HR blood screening detected 66% of all cases positive for THC and/or its metabolites, whereas the LR urine screening failed to detect these compounds entirely. Incorporation of the HighResNPS® database enabled the tentative identification of 14 NPS. Seventy-four (90%) of the 82 DoAs demonstrated accuracy within ± 30%, precision (CV) ≤ 30% and quantitative results of 100 authentic cases were consistent with those from the targeted LC-MS/MS method which is generally considered the gold standard for quantification. Overall, the HR blood screening is superior to the LR urine screening for most analyte classes, enabling simultaneous detection of DoAs, their metabolites and NPS. The semi-quantitative validation of 74 drugs and the quantitative comparison confirmed the method's reliability in distinguishing between subtherapeutic, therapeutic and toxic concentrations without the need for drug class-specific optimization, thereby saving time, effort and costs. This untargeted approach combines screening with (semi)quantification while supporting routine workflows, research applications and retrospective analysis of new emerging substances.
Differential addictive potential of cis- and trans-3-methylfentanyl revealed by pharmacokinetic-pharmacodynamic profiling.
Bai X, Chen Y, Wei ZQ … +7 more , Bian J, Zhou CM, Lv LH, Zheng H, Zhao YB, Rao YL, Xu ZR
J Anal Toxicol · 2026 Jun · PMID 42297570 · Publisher ↗
3-Methylfentanyl (3-MF) is a highly potent synthetic opioid linked to a high risk of overdose. Although its analgesic effects are known to be stereoselective, the differences in addictive potential between its cis- and t...
3-Methylfentanyl (3-MF) is a highly potent synthetic opioid linked to a high risk of overdose. Although its analgesic effects are known to be stereoselective, the differences in addictive potential between its cis- and trans-isomers have not been fully elucidated. This study aimed to compare the abuse liability of cis- and trans-3-MF isomers using behavioral, pharmacokinetic, neurochemical, and transporter-based evaluations in rodents. Conditioned place preference (CPP) was used to assess addiction potential in rodents. Pharmacokinetic profiles were evaluated in rats via intravenous (iv), intramuscular (im), and subcutaneous (sc) routes. Brain microdialysis measured nucleus accumbens (NAc) exposure and monoamine release. In vitro transporter assays assessed interactions with breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp). Cis-3-MF induced CPP at 8-fold lower doses than trans-3-MF (10 vs. 80 µg/kg). Pharmacokinetic analyzes revealed that trans-3-MF had higher plasma exposure after intravenous administration, while cis-3-MF showed nearly 100% bioavailability via intramuscular or subcutaneous routes. Microdialysis demonstrated 2.7-fold greater nucleus accumbens exposure of cis-3-MF and a more rapid and pronounced DA release (Cmax: 67 vs. 37 ng/ml for trans-3-MF). In contrast, trans-3-MF induced a slower increase in DA but elevated 5-HT levels. Trans-3-MF was identified as a partial BCRP substrate, potentially limiting brain penetration. Neither isomer interacted significantly with P-gp. Stereochemistry critically influences the addictive potential of 3-MF isomers. Cis-3-MF demonstrates greater abuse liability, driven by enhanced brain exposure and dopaminergic activation. These findings contribute to understanding stereoselective risks in synthetic opioid toxicity and support improved safety evaluations for novel analogs.
Development and application of a simplified, quantitative method for 30+ New Psychoactive Substances in hair.
Hwang S, Dos Santos BP, Ameer A … +8 more , Schwarz PS, Birk L, Salomone A, Eller S, Franco de Oliveira T, Matias JP, Concheiro-Guisán M, Fonseca Pego AM
J Anal Toxicol · 2026 Jun · PMID 42296389 · Publisher ↗
The rapid emergence of novel psychoactive substances (NPS) poses a significant challenge for forensic toxicology and public health. While blood and urine enable rapid detection for early warning systems, long-term monito...
The rapid emergence of novel psychoactive substances (NPS) poses a significant challenge for forensic toxicology and public health. While blood and urine enable rapid detection for early warning systems, long-term monitoring is essential for retrospective exposure assessment and temporal trend analysis. In this context, hair represents a valuable biological matrix; however, multi-class NPS determination remains difficult due to their chemical diversity and typically low concentrations. In this work, we targeted 12 synthetic opioids, 8 synthetic cathinones, 3 dissociatives, 3 designer benzodiazepines, 3 hallucinogens, and 2 synthetic cannabinoids. Sample preparation included a three-step wash procedure (water, methanol, and ethyl acetate), followed by simultaneous pulverization and methanolic extraction of 20 mg of hair, using an Omni Ruptor bead-mill homogenizer (10 cycles, 40 s at 4.5 m/s with dwell periods; total time ∼43 min). After centrifugation (5000 rpm, 10 min), extracts were evaporated under nitrogen stream at 40°C (20 psi) and reconstituted in 100 µl of 90:10 (v/v) water/acetonitrile, both containing 0.1% formic acid, followed by filtration. Chromatographic separation was achieved by liquid chromatography on a Kinetex C18 column (100 × 2.1 mm, 1.7 µm) using gradient elution with a total runtime of 10 min. Identification and quantitation were performed by tandem mass spectrometry in positive electrospray ionization using multiple reaction monitoring with quantifier and qualifier transitions. The method was validated according to ANSI/ASB Standard 036. Linearity was demonstrated from 5 to 500 pg/mg. Intra- and inter-day precision were <20% and bias within ±20% for most analytes, with no significant carryover or interferences observed. Matrix effects were observed but consistent across analytes, allowing reliable quantitation. Application to authentic hair samples from electronic music festival attendees in Europe and Brazil confirmed the presence of emerging NPS. This integrated pulverization-extraction approach enables rapid, robust multi-class NPS detection in hair for biomonitoring and forensic applications.
Achieving a more accurate method of standard addition through mathematical improvements.
Desharnais B, Abonamah JV, Sofalvi S … +1 more , Mireault P
J Anal Toxicol · 2026 Jun · PMID 42287129 · Publisher ↗
The method of standard addition (MSA) has recently benefited from a popularity boost. In this approach, aliquots from a sample with an unknown analyte concentration are spiked with increasing analyte amounts. When plotti...
The method of standard addition (MSA) has recently benefited from a popularity boost. In this approach, aliquots from a sample with an unknown analyte concentration are spiked with increasing analyte amounts. When plotting the measured signals against the spiked concentrations, the absolute value of the x-axis intercept is the unknown's concentration. Unfortunately, guidance on the best practices for performing MSA is extremely slim. In this article, we rely on literature, mathematical theory, and in silico simulations to build a framework for optimal accuracy when implementing the MSA approach. Our recommendations are as follows. (i) The highest upspike concentration should be as high as possible without saturating the detector; at least five times the estimated unknown concentration is a good rule of thumb. (ii) Adding measurement replicates should be favored over adding new upspike concentrations. (iii) Upspikes towards the low end of the dynamic range should be favored, insofar as their signal is differentiable from the unknown. (iv) To simplify calculations, coordinate swapping should be performed; i.e. signal measurements (e.g. area, area ratio) are recorded as the x values and spiked concentrations as the y values. (v) In performing the least squares regression, weight is set to 1/variance if three or more replicates are available, otherwise, to 1/(signal)2. (vi) If the confidence interval of the quadratic (b2) parameter includes zero, then a linear model should be used for the regression. Otherwise, a quadratic model should be used. (vii) Measurement uncertainty should be calculated using uncertainty contributors uCRM (uncertainty contributed by the certified reference material, as stated on its certificate of analysis) and uMSA (uncertainty contributed by the MSA procedure, which is the uncertainty of the y-intercept, ub0, when using a coordinate-flipped framework).
Implementing an accurate method of standard addition (MSA) using the EZMSA Excel or R tool.
Abonamah JV, Desharnais B, Lebrun É … +2 more , Sofalvi S, Mireault P
J Anal Toxicol · 2026 Jun · PMID 42286421 · Publisher ↗
The method of standard addition (MSA) is a quantification method in which aliquots of an unknown sample are spiked with increasing concentrations of the analyte targeted for quantification. When a regression is performed...
The method of standard addition (MSA) is a quantification method in which aliquots of an unknown sample are spiked with increasing concentrations of the analyte targeted for quantification. When a regression is performed on the resulting dataset, the unknown concentration is estimated by obtaining the absolute value of the intercept with the concentration axis. As described by the authors in the paper "Achieving a more accurate method of standard addition (MSA) through mathematical improvements", optimized selection of the spiked concentrations and calibration model (weight and order) yields more accurate MSA quantification results. This is complemented by measurement uncertainty calculation which adds additional confidence to the quantification result. Save for the selection of upspike concentrations, these improvements call for a level of proficiency in mathematics and programming that goes beyond what is considered basic for a forensic or analytical toxicologist. That is a strong impediment to the dissemination of best MSA practices. To remove this barrier, we developed a user-friendly tool: EZMSA. Available as an Excel spreadsheet and an online or local application, this tool carries out all the optimized MSA calculations for the user. The R application even allows the production of a customized report in PDF, DOCX or HTML formats. Validation of both EZMSA platforms was performed by analyzing various datasets testing the full scope of functions and calculations included in the tool. Two full application examples, where EZMSA is used for the quantification of alprazolam and phenazolam in blood, are also presented. The EZMSA tool for simple implementation of accurate MSA calculations is available for download in its Excel and R formats at https://github.com/ToxBrigitte/ezmsa; and as an online application at https://toxbrigitte.shinyapps.io/EZMSA/.
Delta-9-tetrahydrocannabutol (Δ9-THCB), Delta-9-tetrahydrocannabihexol (Δ9-THCH), and Delta-9-tetrahydrocannabiphorol (Δ9-THCP): the Impact of Varying Alkyl Chain Length on Delta-9-tetrahydrocannabinol (Δ9-THC) Analog Metabolism.
James KM, Poklis JL, Karschner EL … +2 more , Dempsey SK, Peace MR
J Anal Toxicol · 2026 Jun · PMID 42286420 · Publisher ↗
Increasing availability of delta-9-tetrahydrocannabinol (Δ9-THC) analogs including Δ9-tetrahydrocannabutol (Δ9-THCB), Δ9-tetrahydrocannabihexol (Δ9-THCH), and Δ9-tetrahydrocannabiphorol (Δ9-THCP) in unregulated products...
Increasing availability of delta-9-tetrahydrocannabinol (Δ9-THC) analogs including Δ9-tetrahydrocannabutol (Δ9-THCB), Δ9-tetrahydrocannabihexol (Δ9-THCH), and Δ9-tetrahydrocannabiphorol (Δ9-THCP) in unregulated products has raised questions about the impact of alkyl sidechain length not only on potency, but on metabolism. Δ9-THC homologs were metabolized in vitro with human liver microsomes, and multiple time points were collected. Multiple reaction monitoring (MRM) and precursor ion (PI) scanning methods presumptively identified that Δ9-THCB, Δ9-THCH, and Δ9-THCP produced hydroxylated and carboxylated phase I biomarkers, similar to those of Δ9-THC. The use of universal product ions containing a common core highlights their potential to assist laboratories in future identification of novel Δ9-THC analogs. One carbon deviation in alkyl sidechain length resulted in a decreased formation of the hydroxylated biomarker; whereas two carbon deviations further decreased the amount produced. Although the metabolism rate of the hydroxylated biomarkers was reduced, any deviation from the five-carbon sidechain increased the conversion from the hydroxylated biomarker to the carboxylated biomarker by the cytochrome P450 enzymes. Presumptive identification of novel THC analog metabolites provides new analytical targets for toxicology laboratories seeking the causative agent(s) in cases of suspected intoxication and/or drug toxicity. By understanding the metabolism of novel THC analogs, critical information can then be provided to the public regarding the potential risks of these mass-produced products.
Potential for postmortem formation of ethanol in vitreous humor.
Peterson BL, Midthun KM, Labay LM
J Anal Toxicol · 2026 Jun · PMID 42286417 · Publisher ↗
Interpretation of ethanol results in postmortem blood samples has well-known limitations. After death, ethanol can form in the blood if sufficient glucose and microorganisms are present to facilitate the fermentation pro...
Interpretation of ethanol results in postmortem blood samples has well-known limitations. After death, ethanol can form in the blood if sufficient glucose and microorganisms are present to facilitate the fermentation process. The potential for postmortem formation of ethanol has led to the widespread practice of verifying blood ethanol concentrations in a secondary matrix, typically vitreous humor when available. This study examined underlying trends and causes of postmortem ethanol formation in vitreous humor. Postmortem casework from 1 January 2022 to 31 December 2024 was investigated for cases where ethanol was reported in vitreous humor but not detected in a paired blood sample. Volatile analysis was performed by headspace gas chromatography on dual columns with flame ionization detectors. Ethanol, methanol, isopropanol, and acetone were screened in both blood and vitreous humor at reporting limits of 10, 10, 5.0, and 5.0 mg/dL, respectively. During this timeframe, 858 cases were identified with vitreous humor ethanol concentrations ranging from 10 to 624 mg/dL (mean 49 mg/dL, median 20 mg/dL). Of those identified, 683 cases (79%) had low-range vitreous ethanol concentrations (10-49 mg/dL). Possible biomarkers of ketoacidosis were also assessed in the 858 cases, with 464 cases (54%) reporting positive acetone and/or isopropanol. Additionally, elevated levels of beta-hydroxybutyric acid (BHB) (≥ 250 µg/mL) in either the blood or vitreous humor, were detected in 92% of cases (n = 140) tested for BHB; elevated levels of glucose (≥ 200 mg/dL) in vitreous humor were detected in 37% of cases (n = 458) tested for glucose. The results of this study highlight the importance of testing multiple matrices for ethanol in postmortem casework and the potential for postmortem ethanol formation in unpreserved specimens.
Mitragynine and 7-hydroxy-mitragyine plasma pharmacokinetics in humans after single and 15 multiple oral kratom extract doses.
Huestis MA, Brett MA, Bothmer J … +2 more , Henningfield JE, Swift S
J Anal Toxicol · 2026 Jun · PMID 42266029 · Full text
Kratom, a medicinal Southeast Asian plant, gained interest in the United States for its analgesic and stimulant effects. Previous clinical studies characterized mitragynine and 7-hydroxy-mitragynine (7-OH-MTG) plasma pha...
Kratom, a medicinal Southeast Asian plant, gained interest in the United States for its analgesic and stimulant effects. Previous clinical studies characterized mitragynine and 7-hydroxy-mitragynine (7-OH-MTG) plasma pharmacokinetics following kratom tea and dried kratom leaf powder intake; however, to date, there are no kratom extract data. In the current study, mitragynine and 7-OH-MTG plasma pharmacokinetics are characterized in humans following increasing single doses (SD) and 15 multiple daily doses (MD) of concentrated kratom extract (39.5% mitragynine) containing 9.9, 29.6, and 59.2 mg mitragynine. Mean mitragynine plasma Cmax after single escalating doses increased dose-dependently, 32.8 ± 17.0, 93.2 ± 38.6, and 196 ± 77.4 ng/ml at a median Tmax of 1.3 h, with mean 7-OH-MTG Cmax of 6.8 ± 2.7, 13.7 ± 3.3, and 30.5 ± 12.2 ng/mL at a median Tmax of 1.3-1.7 h. Mean mitragynine plasma Cmax after 15 escalating multiple doses increased dose-dependently, 27.4 ± 10.9, 125 ± 79.7, and 277 ± 48.8 ng/mL at a median Tmax of 1.7-2.0 h, with mean 7-OH-MTG Cmax of 5.4 ± 1.9, 16.6 ± 6.1, and 33.9 ± 5.5 ng/mL at a median Tmax of 1.7-2.3 h. Cmax and AUC increased dose-dependently following SD and MD but were less than 1.4X greater than expected for both analytes and all doses based on strict dose proportionality. Half-lives were best reflected at higher doses due to the ability to measure low analyte concentrations longer but also suggested possible enzyme saturation. Higher 7-OH-MTG to mitragynine ratios were observed after multiple doses compared to SD and at lower compared to higher doses. These data indicate that concentrated kratom extracts may yield greater overall mitragynine exposure than dried kratom leaf powder or kratom tea preparations administered at comparable doses.
Drugs in formalin-fixed specimens-a review on reactivity and stability.
Hoffmann J, Picht F, Richter C … +2 more , Blümke-Anbau K, Cepus V
J Anal Toxicol · 2026 Jun · PMID 42266022 · Publisher ↗
Formalin-fixed specimens represent particular challenges in the field of forensic toxicology. Despite being a rare occurrence, the circumstances of certain cases may require toxicological analyses of embalmed or fixed ti...
Formalin-fixed specimens represent particular challenges in the field of forensic toxicology. Despite being a rare occurrence, the circumstances of certain cases may require toxicological analyses of embalmed or fixed tissues. However, the preservation causes a variety of physical and chemical processes influencing the concentration and the detectability of many target analytes. While redistribution of drugs between tissue and formaldehyde solution may be reflected in measuring both tissue and fixing solution concentrations, reactions of target analytes with formaldehyde may lead to more complex behaviour of drugs. Some of those degradation pathways have been comprehensively described, e.g. Eschweiler-Clarke conversion of amines. Considering both the redistribution and reactions of drugs in fixed specimens, most toxicologically relevant substances can be detected, either directly or by identifying specific degradation products. This review summarizes the current knowledge of drug-formaldehyde reactions and documents the stability of a broad variety of drugs.
Analysis of suzetrigine, a novel nonopioid pain medication, in whole blood and urine using liquid chromatography-tandem mass spectrometry.
Parry IR, Skillman BN
J Anal Toxicol · 2026 Jun · PMID 42262902 · Publisher ↗
Suzetrigine (JOURNAVX®) is a novel non-opioid pain medication that was approved in January 2025. Given the well-documented abuse potential of opioids, suzetrigine may become more widely prescribed as an alternative for a...
Suzetrigine (JOURNAVX®) is a novel non-opioid pain medication that was approved in January 2025. Given the well-documented abuse potential of opioids, suzetrigine may become more widely prescribed as an alternative for acute pain management. However, it could still appear in forensic casework as little is understood about its role in polydrug toxicity, comorbidity with pre-existing health conditions, or abuse potential within larger populations. As such, this research aimed to develop the first forensically focused method to detect suzetrigine in blood and urine. Due to its similar physicochemical properties, suzetrigine was seamlessly integrated into a previously validated liquid-liquid extraction method developed for novel dual orexin receptor antagonists (DORAs). This report focuses on the subsequent method development and validation for suzetrigine detection using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was validated in accordance with ANSI/ASB 036 for the quantification of suzetrigine in blood and its qualitative identification in urine. A quadratic calibration model with 1/x weighing was utilized (1.0-1000 ng/ml) with quality controls (QCs) at 1.5, 80, 400, and 800 ng/ml. The limit of detection in blood and urine was 0.25 ng/ml, while the limit of quantitation in blood was 1.0 ng/ml. Post-extraction addition at 5 and 500 ng/ml yielded matrix effects less than ±25%, but increased variability at the low concentration in blood was deemed to have no impact on LOD. No carryover or interferences were observed from the internal standard, matrices, or common drugs. Dilution integrity (5X) was acceptable in blood, and processed samples were stable up to 72 hours in the autosampler. In this report we describe a simple extraction for suzetrigine in blood and urine followed by LC-MS/MS analysis. This analytical workflow will be valuable as the use of suzetrigine becomes more prevalent in casework samples.
Evaluation of gabapentin: a 7-year review of postmortem and driving while intoxicated cases in Dallas County.
Dempsey SK, Glicksberg LC
J Anal Toxicol · 2026 Jun · PMID 42249549 · Publisher ↗
Gabapentin is an approved treatment for epilepsy and neuropathic pain but due to a relatively minimal side effect profile at therapeutic doses it is also prescribed for numerous off-label uses. Due to an increasing numbe...
Gabapentin is an approved treatment for epilepsy and neuropathic pain but due to a relatively minimal side effect profile at therapeutic doses it is also prescribed for numerous off-label uses. Due to an increasing number of prescriptions, the misuse and abuse of gabapentin has also increased. This study reviewed driving while intoxicated (DWI) and postmortem cases positive for gabapentin submitted to the Dallas County Southwestern Institute of Forensic Sciences from January 2018 to December 2025. A total of 3189 cases were positive for gabapentin, of which 87 were DWI and 2973 were postmortem, and was identified in approximately 5% of all casework each year. Average blood concentrations were 3798.1 ng/ml (range 201.9-16 008.0 ng/ml) for DWI cases and 8983.9 ng/ml (range 200.9-180 706.2 ng/ml) for postmortem cases. The primary user of gabapentin were white males in their 40s to 50s for all case types. The substances most commonly identified with gabapentin in postmortem cases were opioids, ethanol, and stimulants and in DWI cases were stimulants, benzodiazepines, and THC and its metabolites. Almost half (47%) of postmortem cases were ruled a natural death by the medical examiner. In 155 cases (5.2%), gabapentin was included in the cause of death, most often listed with other drugs. With an increasing interest in gabapentin in forensic toxicology, the data presented indicates that gabapentin remains a consistent finding in Dallas County casework.
Variability in breath alcohol concentration profiles during controlled social drinking.
O'Connor RS, Wang J, Vargas JR
J Anal Toxicol · 2026 Jun · PMID 42236277 · Full text
Controlled alcohol studies often use standardized dosing conditions to characterize absorption and elimination. The present study evaluated breath alcohol concentration (BrAC) profiles under supervised social drinking co...
Controlled alcohol studies often use standardized dosing conditions to characterize absorption and elimination. The present study evaluated breath alcohol concentration (BrAC) profiles under supervised social drinking conditions that permitted variability in beverage consumption and food intake. Forty-two adult participants consumed self-selected 80-proof mixed drinks with ad libitum access to food. Drinking duration ranged from 45 to 172 min (mean 108 min, median 110 min), reflecting substantial variability in consumption time across participants. BrAC was measured at approximately 30-min intervals using an Intox EC/IR II until return to zero. Peak BrAC ranged from 0.040 to 0.117 g/210 L (mean 0.087). Time from the final drink to peak ranged from -23 to 76 min (mean 17 min, median 13 min). The mean elimination rate was 0.0186 g/210 L/hr (SD 0.0027, range 0.0134 to 0.0261). Most participants reached peak concentration shortly after drinking ceased, although delayed peaks of more than 1 hr were observed in some individuals. Representative curves demonstrated variability in absorption timing, including occasional multi-peak profiles, while post-peak elimination was generally linear. These findings characterize the range of BrAC-time patterns observed under supervised social drinking conditions and provide context for interpreting alcohol measurements in applied settings.
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