Research linking substance use with HIV risk behaviors and antiretroviral therapy adherence is typically based on self-reported data. However, studies in high-income countries show that men who have sex with men (MSM) often underreport substance use when compared to objective biological testing. Such comparisons have not been conducted among MSM in sub-Saharan Africa. We compared self-reported and objectively measured substance use among MSM participating in HPTN 075, a multi-site observational cohort study conducted in Kenya, Malawi, and South Africa. Urine samples (n = 734) from 382 participants were tested for the alcohol metabolite ethyl glucuronide and 43 other substances. These tests detect alcohol use in the prior 48-72h and other substances up to 7 days earlier, depending on the drug. Of the 734 samples, 159 (21.7%) tested positive for ethyl glucuronide. Self-reported alcohol use was available for 97.5% of these cases and confirmed in 141 (91.0%) of them. Sixty samples (8.2%) tested positive for at least one of the 43 other substances. Self-report data were available for 95.0% of those, but use was acknowledged in only 19 (33.3%) cases. These findings suggest that alcohol use is generally reported accurately, while drug use is substantially underreported-likely due to legal prohibitions and social stigma. Incorporating objective substance testing alongside self-reports is recommended to improve the accuracy of substance use measurement in behavioral and clinical HIV research, especially in contexts where stigma or criminalization may inhibit disclosure.

Elimination of EtG and EtS between two consecutive blood samples in apprehended drivers.

The primary aims of this best practice article are to provide a laboratory perspective of the merits and pitfalls of different markers currently in use in UK National Health Service (NHS) hospital laboratories, and how best these tests can be used for the detection of heavy (harmful) alcohol consumption. Included are suggested testing algorithms for carbohydrate-deficient transferrin (CDT), ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth16:0/18:1), for the purpose of creating suitable bench-to-bedside alcohol services in support of the delivery of hospital alcohol strategy, and the NHS long-term health plan.

Background/Objectives: Alcohol and smoking during pregnancy may be associated with several complications, but the underlying mechanism is still unclear. The aim of this study was to evaluate the role of oxidative stress induced by smoking and alcohol during pregnancy and their effects on fetal and neonatal outcomes. Material and methods: We considered pregnant women at term. Validated questionnaires were used to investigate smoking and alcohol habits. Ultrasound was performed to evaluate fetal weight, amniotic fluid index, and maternal-fetal Doppler velocimetry. At the time of delivery, we collected a tuft of maternal hair, maternal venous blood, and cord blood. In these samplings we determined in phase I nicotine, cotinine, and ethyl glucuronide on the maternal keratin matrix with the gas chromatography-mass spectrometry technique. In phase II, the Free Oxygen Radicals Test (FORT) and Free Oxygen Radical Defense (FORD) test were used to assess circulating reactive oxygen species (ROS). Results: 119 pregnant patients were enrolled (n = 62 for smoking and n = 57 for alcohol). Twenty-six patients (42%) out of 62 were active smokers. Three patients (5%) out of 57 were alcoholic consumers. Mean neonatal weight and mean placental weight were significantly lower for active smokers (p = 0.0001). The neonatal weight was in the 1st-2nd percentile for all alcohol abusers. Considering two subgroups (n = 10 non-smokers and n = 10 smokers) for ROS determination, a statistically significant higher oxidative stress in the blood of smoking patients was evidenced (p < 0.0001). In cord blood the differences were not statistically significant (p = 0.2216). Conclusions: Fetal growth restriction was present in the group of active smokers and in patients with alcohol abuse. Oxidative stress was higher in smoking patients than in non-smokers. However, in cord blood, FORT was negative in all cases, suggesting a protective mechanism in utero. Given the limited sample size, the results obtained are preliminary and require future studies.

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. 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. 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. 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.

Urinary alcohol and ethyl glucuronide as a screening tool for alcohol use in pregnancy; a multicentre prospective study

BackgroundPhosphatidylethanol (PEth), ethyl glucuronide (EtG), and ethyl sulphate (EtS) are highly sensitive and specific biomarkers of alcohol intake. This study investigated their application and relationship to traditional self‐report measures in a mixed cohort of liver disease patients to guide decision making in liver transplant populations.MethodsWe recruited 183 participants (mean age 49.2 years, 62% male), with N = 99 liver disease (88% alcohol‐associated liver disease [ALD]), N = 35 alcohol use disorder (AUD), and N = 49 healthy volunteers. Patient‐reported alcohol intake and AUDIT score served as references and were compared to traditional biomarkers, PEth and serum EtG/EtS. Receiver operating characteristic (ROC) analysis and a range of biomarker cutoffs were examined to determine optimal test characteristics. A subset of blood samples modified to a standardized hematocrit analyzed the relationship between hematocrit and PEth.ResultsCompared to traditional biomarkers, both PEth and EtG were sensitive and specific for alcohol intake. At the limit of detection (LOD), PEth was 95% sensitive at detecting any drinking. PEth cutoff of 300 μg/L was 86% sensitive and 92% specific for “heavy drinking,” and 600 μg/L was 88% sensitive and specific for “very heavy drinking.” PEth displayed superior test characteristics (sensitivity, specificity, PPV, NPV, and AUC) to all measured traditional biomarkers over two‐day and one‐month time frames. A subset of participants suspected of drinking but reporting abstinence had positive PEth tests (35%), suggestive of unreported drinking. PEth was positively correlated with hematocrit (r2 = 0.83, p < 0.01) and correction to a standardized median resulted in increases in PEth concentration in most cases.ConclusionsPEth is clinically useful as an alcohol biomarker in patients with liver disease and is superior to traditional biomarkers, providing good test characteristics for “heavy” and “very heavy” drinking using stepwise cutoffs. PEth detected a subset of patients underreporting their alcohol use, with implications for the management of patients in liver transplant clinics.

In intervention studies, alcohol consumption is often measured by self-report alone, which can be impacted by social desirability, recall, and other biases. Biomarkers and biosensors have gained popularity as objective measurements of alcohol consumption that can improve the accuracy of results. This scoping review provides a narrative overview and describes the use of biomarkers in alcohol intervention studies to inform future research. We conducted a review of alcohol intervention literature including published studies and Clinicaltrials.gov registrations (2000-2021). Randomized controlled trials, quasi-experimental, and nonexperimental studies were included if they piloted or evaluated an intervention aimed at reducing unhealthy alcohol consumption and if an alcohol biomarker was used. Data charting included type of biomarker(s), the country and context of the study location, and a description of how the biomarker was used in analysis. We identified 168 alcohol intervention studies that included at least one biomarker. Blood alcohol content was the most used (N = 76). There was an upward trend in biomarker use over time; 24% of studies were published between 2000 and 2010, and 76% between 2011 and 2021. The use of direct biomarkers, phosphatidylethanol and ethyl glucuronide, and biosensors has increased in frequency over time relative to indirect biomarkers, such as aspartate aminotransferase, carbohydrate-deficient transferrin, and alanine aminotransferase. Most studies were conducted in high-income countries; only 15% were conducted in a low- or middle-income country. More than half of completed studies did not report on comparisons between self-report and biomarker results even when both were collected. Among studies that did report a comparison, 26% reported discordance between self-report and biomarker results. The use of direct biomarkers and biosensors is accelerating. There is a need for more consistency in reporting biomarker/self-report concordance results, more comparisons between multiple biomarkers, and for greater geographic representation within the alcohol biomarker literature.

Alcohol consumption is widespread worldwide and a leading cause of injuries, morbidity, and mortality. Accurately detecting alcohol use with reliable biomarkers is crucial in clinical and forensic settings. Direct alcohol biomarkers, i.e., ethanol (EtOH), ethyl glucuronide (EtG), ethyl sulphate (EtS), phosphatidylethanol 16:0/18:1 (PEth) reflect short- and long-term consumption. Nevertheless, complementary biomarkers with improved specificity and sensitivity are needed to better assess alcohol use, including generating a detailed timeline of consumption. Invitro exposure of HepaRG liver cells to EtOH resulted in the generation of ethylated phosphorylcholine (EtOChoP). This is the first study to investigate the invivo presence of EtOChoP and its occurrence in medico-legal samples. Proof-of-concept and observational studies assessed EtOChoP, PEth, EtG, EtS, and EtOH in whole blood, and, when available, other matrices were analyzed for EtG, EtS (plasma, serum, urine, hair), EtOH (urine), and EtOChoP (plasma, serum). A single alcohol exposure event (0.5 g/kg EtOH, with blood EtOH concentration peaking at 0.76 g/L at 100 min) led to EtOChoP presence, and, similar to short-term biomarkers (e.g., EtOH, EtG, and EtS in whole blood), EtOChoP was not detected in the following day(s). However, in the observational study, EtOChoP remained detectable even when short-term biomarkers were absent, resembling long-term biomarkers (PEth and hair EtG). Notably, 14% of samples were positive only for EtOChoP, highlighting the need for additional biomarkers. These findings identify EtOChoP as a promising alcohol (ab)use biomarker formed after EtOH consumption and possibly accumulating during chronic drinking. EtOChoP could potentially differentiate between recent drinking and chronic problematic drinking in individuals with high PEth levels.

Phosphatidylethanol and ethyl glucuronide to categorize alcohol consumption in alcohol-related cirrhosis.

ABSTRACTMonitoring long‐term alcohol consumption is critical in forensic and public health contexts. Hair analysis of ethyl glucuronide (EtG), a direct metabolite of ethanol, has become a standard method for detecting chronic alcohol use. While the reliability of EtG hair testing is well established for short‐ and medium‐term analyses, its stability in hair stored over extended periods has not been comprehensively evaluated. This limitation is especially relevant in retrospective investigations, postmortem evaluations, and long‐term epidemiological studies, where archived samples may be analyzed years after collection. In this study, we assessed the long‐term stability of EtG in human hair stored for up to 10 years. A total of 909 samples originally analyzed between 2013 and 2022 were re‐tested in 2023 using a previously published and validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. When the results of the old and the new analyses were compared, EtG concentrations showed no significant degradation over time, with more than 80% of the samples displaying matching values when analytical uncertainty was considered. Only a small fraction of samples (4.4%) dropped below the commonly used interpretive threshold for chronic alcohol use (30 pg/mg) after 10 years of storage. These findings provide robust evidence that EtG remains chemically stable in hair under standard storage conditions over a decade, confirming the reliability of archived samples for assessing alcohol use history and expanding the utility of EtG analysis in long‐term toxicological and forensic investigations. The demonstrated stability strengthens confidence in hair as a matrix for retrospective substance use evaluation across scientific disciplines.

Vitreous humour is used to assess intoxication at the time of death due to its anatomical isolation, which reduces contamination risk. Toxicological analysis typically includes drugs and alcohol. For interpreting post-mortem ethanol concentrations, distinguishing between ante-mortem ingestion and post-mortem production from putrefaction is essential. For this purpose, biomarkers like ethyl glucuronide (EtG) and ethyl sulfate (EtS) are crucial for confirming alcohol consumption. Factors such as post-mortem interval (PMI), the cause of death, individual characteristics like sex, age, body mass index (BMI), ambient temperature at corpse discovery, and body storage temperature may affect vitreous humour analysis. The present review explores how these factors have been integrated into the current scientific discussion on the quantification of ethanol, EtG and EtS in vitreous humour, and how they ultimately impact the determination of the cause of death. Our findings indicate that the PMI is often unspecified in reviewed cases (64%), and when mentioned, it is under 24h (17%). Individual characteristics like sex, age, and BMI are frequently omitted (43%, 46%, and 86%, respectively), and details on ambient and storage temperatures are rarely provided. Although post-mortem alterations in ocular anatomy are well-documented, there are limited studies that report ethanol stability in vitreous humour across various PMIs. For EtG and EtS, no studies have evaluated quantitative changes in vitreous humour in relation to PMI. Despite these data gaps, available studies suggest that age and BMI may influence the analysis of ethanol in cases of alcohol-related deaths, underscoring the need for further research on factors affecting substance levels in vitreous humour.

The need for objective diagnostic tools in people with alcohol intake abuse is one of the major needs in daily clinical practice. Determination of blood alcohol concentration is commonly used in cases of suspected acute alcohol intoxication, especially in the emergency room. A dose-dependent correlation between alcohol consumption and mean corpuscular volume (MCV) is a known index of excessive alcohol intake. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels are frequently elevated (2-4 times above normal) in patients with alcohol use disorder and an AST/ALT ratio >2 is indicative of alcohol-related liver disease. Several studies highlighted a positive correlation between alcohol consumption and serum gamma-glutamyl transferase (γGT) levels, with increased values in about 75% of patients drinking >60 g/day of ethanol for at least 5 weeks. Also, 60-80 g of alcohol per day for a minimum of 2 weeks can result in increased carbohydrate-deficient transferrin (CDT) levels (normally less than 2% of total transferrin). Complete abstinence from alcohol leads to a normalization of CDT values in approximately 2-3 weeks. Ethyl glucuronide (EtG) is detectable in urine from a minimum of 6 hours up to a maximum of 100 hours after alcohol intake. In-vitro studies showed that the levels of phosphatidylethanol (PEth) in human red blood cells were proportional to ethanol concentration and exposure time, suggesting an important role in differentiating abstinence from unhealthy drinking. γGT and CDT are the most useful markers for monitoring chronic alcohol abstinence, whereas blood alcohol concentration and urinary EtG are the most valuable indexes of acute alcohol consumption. In conclusion, no specific laboratory marker alone is reliable to identify patients with alcohol abuse, thus the best diagnostic strategy includes combined index use in addition to other screening tools (i.e., clinical history/context and questionnaires).

To determine if adults with an alcohol use disorder (AUD), who had a preintervention urine ethyl glucuronide (uEtG) level predictive of nonresponse to contingency management (CM), would respond to two intervention modifications (https://clinicaltrials.gov/ ID: NCT03481049). One hundred fifty-eight adults (53.2% female) with AUD, serious mental illness, and a mean uEtG ≥ 350 ng/mL over a 4-week induction period were randomized to (a) usual CM (uEtG-negative [<150 ng/mL] samples reinforced with $1,686); (b) high magnitude CM (uEtG-negative samples reinforced with $2,983); or (c) shaping CM (reduced drinking [uEtG < 500 ng/mL] samples reinforced for 4 weeks, then uEtG-negative samples reinforced for 12 weeks with $1,686). The primary outcome was uEtG-negative samples during induction and Weeks 5-16 of CM. The relationship between outcomes and uEtG-defined heavy drinking (≥ 500 ng/mL) immediately prior to randomization was assessed. CM conditions did not differ in uEtG-negative samples during the intervention period, Wald, χ²(2) = 1.96, p = .46. Participants were 4.2 times (95% CI [3.02, 5.92], p < .01) more likely to submit a uEtG-negative sample during CM, relative to induction. Those with a heavy drinking uEtG result immediately before randomization were less likely to submit uEtG-negative samples during CM, Wald, χ²(1) = 15.33, p < .01. CM modifications were not associated with lower levels of alcohol use. Participants engaged in less alcohol use during CM, relative to induction. Two patterns of response to CM were observed based on uEtG-defined heavy drinking immediately prior to CM. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Alcohol abuse is a widespread addiction globally, leading to long-term health issues and social consequences. Ethyl glucuronide (EtG) and ethyl palmitate (EtPa) are frequently requested by local authorities, solicitors, or private individuals to assess long-term chronic excessive alcohol consumption. In this paper, we present a validation process aimed at developing sensitive methods for detecting EtG and EtPa in hair samples. EtG was extracted by overnight sonication in water followed by sample clean-up using solid phase extraction (SPE) and analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). EtPa was extracted using a simple ultrasonication extraction followed by analysis using gas chromatography-tandem mass spectrometry (GC-MS/MS). The analytical method was validated by assessing linearity, precision, accuracy, recovery, sensitivity, and selectivity. Both EtG and EtPa methods obtained a coefficient of determination (r2) above 0.999 across concentration ranges of 4, 8, 16, 24, 48, and 96 pg/mg and 120, 240, 360, 480, 600, and 720 pg/mg. Extraction recoveries were both close to 100% with stable retention times and proven sensitivity and selectivity. These methods were validated according to the standards set by the United Kingdom Accreditation Service (UKAS) Lab51 and ISO 17025.

Alcohol is the most well-known toxic substance, the negative impact of which on human health and lifestyle is proven. Chronic alcoholism is a pathological condition that occurs after excessive alcohol consumption and can be observed in young and middle-aged men. The aim of the study is to determine the characteristics of the age-sex distribution and pathomorphological changes of the heart and vessels in forensic cases of alcoholic cardiomyopathy (ACMP). Material and methods. In our study, changes in the left ventricular myocardium due to alcohol consumption were investigated in 70 bodies of those who died at home under suspicious circumstances and were sent to the State Specialized Institution "Main Bureau of Forensic Medical Examination of the Ministry of Health of Ukraine" to determine the cause of death. Bioethics. The study was conducted in accordance with the ethical principles set forth in the Declaration of Helsinki (1964) and subsequent amendments thereto. Ethical approval was obtained from the Committee on Ethics of Scientific Research, Experimental Developments and Scientific Works of the Danylo Halytskyi Lviv National Medical University (excerpt from protocol No. 14 dated December 20, 2023). All data were anonymized and processed in strict confidentiality to preserve the privacy of the deceased and their families. Scientific research. "A study of pathogenetic mechanisms and pathomorphological features of endocrine, cardiovascular, respiratory, nervous, digestive, urinary, and reproductive systems and perinatal period diseases with the aim of improvement of their morphological diagnostics." Topic code: IN.07.00.0001.18. State registration number: 0122U201668 Results. The studied group with ACMP comprised 70 deceased people aged 16 to 40. Of these, 49 (70%) were aged 31 to 40. Of these, 51 (72.8%) were men, and 19 (27.2%) were women. Among the concomitant pathologies, chronic alcoholic hepatitis and hepatosis, as well as left-sided lower lobe bronchopneumonia, were detected in a third of cases. Additionally, in 8 (11.4%) cases, pulmonary embolism was found, associated with the presence of parietal thrombi. The final cause of death of the deceased was acute cardiac and cardiorespiratory failure, which arose as a result of heart damage. In 64.3% of people, a high level of ethyl glucuronide was found in the blood, which indicates alcohol consumption 96 hours before death. Heart lesions were represented by dilated cardiomyopathy and myocardial fibrosis. Conclusion. Histological features of ACMP include parenchymal remodeling with dystrophic changes, uneven hypertrophy of cardiomyocytes against the background of stromal, perivascular, and subendocardial fibrosis; intimal “cushion-like” protrusions and sclerosis of intramural arteries; microcirculatory disorders with sludge phenomenon; and focal-diffuse lipomatosis of the wall of the left and right ventricles to the subendocardial sections. Myocardial fibrosis was focal or diffuse, developed mainly in the interstitial spaces around blood vessels, and was accompanied by the proliferation of connective tissue cells of fibroblasts, simultaneously with a decrease in the number of myocytes.

Abstract Ethanol is a naturally occurring molecule produced via fermentation of sugar-rich foods by yeast. Ethanol catabolism is followed by production of secondary metabolites such as ethyl glucuronide (EtG), which can be measured to provide a retrospective view of dietary exposure. To date, occurrence of this molecule has not been studied in vertebrates other than humans and several other mammalian taxa. Here, we describe a method of testing for the presence of EtG in bird feathers and livers using mass spectrometry. Birds that regularly consume fruit and nectar may accordingly be ingesting ethanol on a chronic basis. We predicted that avian species with diets rich in fermentable sugars consume physiologically significant amounts of ethanol and therefore accumulate detectable levels of EtG. The suitability of EtG assays was tested across 17 avian species representing a diversity of diets. Assays of avian feathers yielded positive results for 10 of 17 avian species; EtG was also present at substantial levels in the livers of two of five study species. We found that EtG was present in nectarivorous hummingbirds but also in species in other trophic niches (three granivores, one omnivore, three invertivores, and one vertivore). Dietary exposure to ethanol may thus be much more widespread than has previously been recognized, and diverse features of avian nutritional ecology (e.g., secondary consumption via ingestion of prey items) may contribute to its accumulation in tissues.

To determine whether there were within-week associations between changes in alcohol use and changes in cannabis, cocaine or amphetamines use and, if so, to ascertain whether these associations varied by naltrexone use among adult sexual and gender minority men (SGMM) with mild and moderate alcohol use disorder (AUD). Secondary analyses of data from the Say When study, a double-blind placebo-controlled trial comparing targeted oral naltrexone (50 mg) to placebo for AUD over 12 weeks. Procedures were conducted at the San Francisco Department of Public Health from May 2015 to November 2020, in San Francisco, California, USA. 98 of 120 SGMM who reported substance use beyond alcohol. Mixed effects logistic regression models tested associations between alcohol exposures [ethyl-glucuronide (EtG)-positive urine screens, past-week binge drinking and past-week binge drinking frequency] and same-week use of other substances (positive urine screens for cannabis, cocaine or amphetamines), adjusting for age, race/ethnicity, income, depression score and treatment assignment. Associations by treatment assignment (naltrexone or placebo) were also evaluated. Having a positive EtG urine screen was associated with higher odds of positive urine screens for cannabis [adjusted odds ratio (aOR) = 2.93, 95% confidence interval (95% CI) = 1.37-6.30, P = 0.006) or cocaine (aOR = 3.08, 95% CI = 1.52-6.23, P = 0.002). Each additional binge drinking day was associated with higher odds of having a positive urine screen for cocaine (aOR = 1.29, 95% CI = 1.04-1.60, P = 0.018). Among those receiving naltrexone, greater binge drinking days was associated with increased odds of having a positive urine screen for cocaine (aOR = 1.64, 95% CI = 1.18-2.27, P = 0.003), while results for cannabis and amphetamines were not statistically significant. Among adult sexual and gender minority men enrolled in a clinical trial, alcohol use was positively associated with cannabis and cocaine use. Naltrexone may mitigate cocaine use in this group by moderating binge drinking or diminishing the rewarding effects of cocaethylene. Findings highlight the potential of targeted naltrexone as an intervention to address alcohol and cocaine co-use and improve treatment outcomes in this underserved group.

Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are mostly analyzed in urine; consequently, most kinetic studies are based on urine samples. In forensic cases, however, it may be necessary to determine these alcohol biomarkers in serum, whole blood, or capillary blood. While there are sufficient data on EtG and EtS in serum after alcohol consumption, the amount of data available on whole blood concentrations is small. Therefore, data on corresponding blood-to-serum ratios seem to gain importance. This study provides data on a drinking experiment with 5 drinking episodes, where serum and whole blood samples were taken simultaneously from 11 healthy participants over 10 days. The samples were analyzed for EtG, EtS, and ethanol. EtG and EtS analysis in whole blood and serum were performed by liquid chromatography-tandem mass spectrometry; ethanol was determined by gas chromatography-flame ionization detection and an alcohol dehydrogenase-based method. EtG and EtS reached their maximum concentration 4-7 h after alcohol consumption. For EtG, a mean blood-to-serum ratio of 0.58 with a range from 0.38 to 0.73 was found; for EtS, the mean ratio was 0.81 with a range from 0.61 to 0.92, indicating a predominant distribution in the serum. For both analytes, high correlation coefficients were obtained when plotting concentrations in serum against concentrations in whole blood. Concerning elimination profiles of the individuals, no time or concentration dependence of EtG or EtS blood-to-serum ratios could be deduced. Neither for EtG nor for EtS was a regularity of curve progressions observed in our test specimens.

Ethyl glucuronide detection in hair (H-EtG) effectively diagnoses long-term abstinence and differentiates between social and chronic excessive alcohol use. However, hair testing does not capture alcohol consumption within the week prior to sample collection. To address this limitation, blood tests like phosphatidylethanol (PEth) and blood ethyl glucuronide (B-EtG) are used alongside H-EtG, extending alcohol detection from minutes after drinking up to the period covered by hair. A total of 1205 cases were selected, where H-EtG was analysed in hair segments over 3 cm long, and concurrent fingertip blood samples in dried blood spots (DBSs) were analysed for PEth and B-EtG using UPLC/ESI-MS/MS with cut-offs: H-EtG = 5 pg/mg, PEth = 20 ng/mL and B-EtG = 10 ng/mL. A total of 468 (39%) cases showed H-EtG, PEth and B-EtG levels below cut-off, consistent with abstinence, while 198 (16%) were above cut-off, indicating continuous alcohol consumption. The remaining cases exhibited various patterns. B-EtG was negative in 282 cases (23%), with H-EtG and PEth detected, suggesting alcohol use but not recently. PEth was positive, but H-EtG and B-EtG were negative in 149 cases (12%), indicating alcohol use within a month, but not recently. H-EtG was positive in 78 cases (6%), with PEth and B-EtG negative, confirming recent abstinence. H-EtG was negative in 27 cases (2%), indicating no alcohol use for months, but recent consumption was confirmed by the detection of PEth and B-EtG. Only two cases (0.2%) had positive B-EtG with negative H-EtG and PEth, indicating recent alcohol use. The results confirm the value of combining H-EtG with concurrent blood testing of PEth and B-EtG, significantly enhancing drinking history assessment.