Evaluation of Phosphatidylethanol Elimination in Alcohol Use Disorder Patients Undergoing Withdrawal Treatment.

AIMS: Phosphatidylethanol (PEth) is used to monitor alcohol consumption in alcohol use disorder (AUD). In this study, we aim to evaluate the elimination time of PEth with regard to the clinically established 200 and 20 ng/ml cutoffs for PEth 16:0/18:1. METHODS: Data from 49 patients undergoing treatment for AUD were evaluated. PEth concentrations were measured at the beginning and repeatedly during the treatment period of up to 12 weeks to monitor the elimination of PEth. We evaluated the time in weeks until the cutoff concentrations of <200 and <20 ng/ml were achieved. The correlation between the initial PEth concentration and the number of days until the PEth concentration had dropped below 200 and 20 ng/ml was assessed by calculating Pearson's correlation coefficients. RESULTS: The initial PEth concentrations ranged from <20 to >2500 ng/ml. In 31 patients, the time until the cutoff values were reached could be documented. Even after 6 weeks of abstinence, PEth concentrations above the cutoff of 200 ng/ml could still be detected in two patients. A strong significant positive correlation was found between the initial PEth concentration and the time required to drop below the two cutoffs. CONCLUSION: A waiting period of more than 6 weeks after declared abstinence should be granted for individuals with AUD before using only one single PEth concentration to assess the consumption behavior. However, we recommend to always use at least two PEth concentrations for the evaluation of alcohol-drinking behaviors in AUD patients.

Alcohol Biomarker Phosphatidylethanol as a Predictor of the Severity of Alcohol Withdrawal Syndrome.

AIMS: to investigate the relationship between phosphatidylethanol (PEth) and withdrawal severity in patients with alcohol use disorder (AUD). METHODS: in 34 patients with AUD admitted for treatment of acute alcohol withdrawal, data were available for initial blood PEth concentrations and scores throughout detoxification of symptoms of withdrawal assessed by trained medical staff using the alcohol withdrawal syndrome (AWS)-scale, a validated scale consisting of 11 items in the alcohol withdrawal syndrome (two subscales with seven physiological and five psychological symptoms). RESULTS: a significant positive correlation between PEth and the severity of alcohol withdrawal was found. When the sample was divided into two groups, according to whether or not AWS score at some point in the treatment reached 6 or more, the median PEth score was higher in those whose peak score had been 6 or more (score of 6 being the suggested cutoff to start medicating the withdrawal syndrome). Although there was a trend for some aspects of the clinical history to be more 'severe' in those with higher AWS, no differences reached significance. CONCLUSION: blood PEth on admission could have a role in identifying patients at risk of more severe AWS.

Phosphatidylethanol Reliably and Objectively Quantifies Alcohol Consumption in Adolescents and Young Adults.

BACKGROUND: Alcohol contributes to numerous annual deaths and various societal problems not just in adult, but also in adolescent, populations. Therefore, it is vital to find methods for reliably detecting alcohol use for early preventative measures. Research has shown phosphatidylethanol (PEth) to be superior to self-report instruments and indirect biomarkers for alcohol consumption in adult populations. However, the transferability onto an adolescent population has not yet been investigated. METHODS: N = 106 adolescents and young adults aged between 13 and 21 years were included. PEth analysis using high-pressure liquid chromatography-tandem mass spectrometry was performed on dried blood spot samples. Self-report questionnaires for alcohol consumption (Alcohol Use Disorders Identification Test-Consumption, AUDIT-C, and Timeline Followback, TLFB) and drug and alcohol consumption (Detection of Alcohol and Drug Problems in Adolescents, DEP-ADO) were completed by each participant. RESULTS: AUDIT-C scores showed large correlations with PEth 16:0/18:1 (rs  = 0.732) and PEth 16:0/18:2 (rs  = 0.661) concentrations. AUDIT-C with a cutoff value ≥3 was largely correlated with PEth 16:0/18:1 (η = 0.411) and showed a medium-sized correlation with PEth 16:0/18:2 (η = 0.397) concentrations. Using an AUDIT-C cutoff value ≥5 showed large correlations with both PEth 16:0/18:1 (η = 0.510) and PEth 16:0/18:2 (η = 0.497) concentrations, respectively. ROC curves indicated higher PEth concentrations are a good model for detecting positive AUDIT-C cutoff values (AUROC range: 0.800 to 0.849). PEth concentrations showed medium to large correlations with DEP-ADO and TLFB subscales (range rs  = 0.469 to 0.746). CONCLUSION: The results suggest that PEth is a reliable and objective marker for quantifying alcohol consumption in adolescents and young adults. This could be of importance for early preventative measures against hazardous alcohol consumption, which is increasingly common at younger ages.

Dysfunctional approach behavior triggered by alcohol-unrelated Pavlovian cues predicts long-term relapse in alcohol dependence.

We demonstrated that alcohol-dependent patients who relapsed within 1 year after detoxification showed stronger PIT effects compared with abstainers and controls. Relapsers particularly failed to correctly perform in trials where an instrumental stimulus required inhibition while a Pavlovian background cue indicated a monetary gain. Under that condition, relapsers approached the instrumental stimulus, independent of the expected punishment. The failure of inhibiting an aversive stimulus in favor of approaching an appetitive context cue reflects dysfunctional altered learning mechanisms in relapsers.

Determination of the stereoisomeric distribution of R-(-)- and S-(+)-methamphetamine in Thai pills in the legal context of "not inconsiderable quantities".

In Germany, the severity of a narcotic offence is determined based on the classification into different categories of quantity. Recently, an amendment to the Narcotics Law regarding the "not inconsiderable quantities" was introduced. The new limits for methamphetamine are derived from the varying potency of the respective enantiomers. Switzerland, however, does not practice this distinction and there is only one limit quantity, without considering the isomeric structure. To examine whether this single value is still contemporary, 26 Thai pill samples from the years 2000, 2001, 2007, 2009 and 2017 were analyzed by HPLC-MS/MS and GC-MS. Both methods resulted in similar stereoisomeric distributions: the pills mainly consist of the more potent S-(+)-methamphetamine, some even being enantiopure. Others show enantiomeric mixtures of R-(-)-/S-(+)-methamphetamine, but rarely in an equimolar ratio. There even was one sample, where mainly the less potent R-(-)-methamphetamine was detected. In conclusion, the analyses revealed that the single value for a "not inconsiderable quantity" in Switzerland seems outdated. Most of the sized pills showed a much higher concentration of the more potent S-(+)-methamphetamine. The risks related to taking such a pill are much higher and therefore the limit quantity should be adapted to the potency of the respective enantiomers.

Cannabinoid concentrations in confiscated cannabis samples and in whole blood and urine after smoking CBD-rich cannabis as a "tobacco substitute".

In Switzerland, only cannabis with a total Δ9-tetrahydrocannabinol (THC) content higher than 1% is controlled by the narcotics legislation. Cannabis products rich in cannabidiol (CBD) and low in THC can be legally sold as tobacco substitutes. In this paper, we address analytical and forensic toxicological issues related to the increasing availability and consumption of these products. Based on the analysis of 531 confiscated cannabis samples, we could establish classification thresholds: plant material with a ratio of total THC/total CBD ≥ 3 is graded as THC-rich/CBD-poor, whereas samples with a ratio ≤ 0.33 are categorized as CBD-rich/THC-poor cannabis. We also evaluated an on-site test kit as a rapid alternative to the laborious liquid or gas chromatography (LC or GC)-based techniques normally used for the differentiation between THC- and CBD-cannabis. Furthermore, we determined whole blood and urine cannabinoid levels after smoking different doses of legal CBD-cannabis. A male volunteer smoked one cigarette within 15 min and four cigarettes within 1 h and within 30 min, respectively. Cigarettes contained on average 42.7 mg CBD and 2.2 mg THC. Blood samples were collected up to 1.1 h and urine samples up to 27.3 h after the beginning of smoking. All urine samples tested negative by three immunochemical assays for detection of cannabis use. This is an important finding for abstinence monitoring. However, we found that the trace amounts of THC present in CBD-cannabis can produce THC blood levels above the Swiss legal limit for driving, and thus render the consumer unable to drive from a legal point of view.

High-Resolution Ion Mobility Spectrometry for Rapid Cannabis Potency Testing.

We report initial results from an ion mobility spectrometry (IMS)-based analysis of natural cannabis samples and explore the possibility of using this technique to distinguish medical marijuana from illegal forms of the drug, as defined by Swiss legislation. We analyzed cannabis extracts by electrospray ionization IMS-MS and found that high-resolution drift-tube IMS ( R > 150) can effectively isolate and quantify the controlled substance, Δ9-tetrahydrocannabinol (THC), even in the presence of other noncontrolled cannabinoid isomers including cannabidiol (CBD). We used this information to determine whether the THC content of a given sample surpassed the legal limit, which is 1% by weight in Switzerland. Our IMS-MS methodology produced equivalent quantification results to standard HPLC-based methods and offers the additional advantage of significantly shorter time requirements for the analysis. In addition, IMS-based analysis offers flexibility over HPLC in that it can be performed on portable devices. As such, these findings may have implications for cannabis testing in police laboratories.

Introduction of sample tubes with sodium azide as a preservative for ethyl glucuronide in urine.

Ethyl glucuronide (EtG) is a direct alcohol marker, which is widely used for clinical and forensic applications, mainly for abstinence control. However, the instability of EtG in urine against bacterial degradation or the post-collectional synthesis of EtG in contaminated samples may cause false interpretation of EtG results in urine samples. This study evaluates the potential of sodium azide in tubes used for urine collection to hinder degradation of ethyl glucuronide by bacterial metabolism taking place during growth of bacterial colonies. The tubes are part of a commercial oral fluid collection device. The sampling system was tested with different gram-positive and gram-negative bacterial species previously observed in urinary tract infections, such as Escherichia coli, Staphylococcus aureus, Enterecoccus faecalis, Staphylococcus epidermidis, Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomonas aeruginosa. Inhibition of bacterial growth by sodium azide, resulting in lower numbers of colony forming units compared to control samples, was observed for all tested bacterial species. To test the prevention of EtG degradation by the predominant pathogen in urinary tract infection, sterile-filtered urine and deficient medium were spiked with EtG, and inoculated with E. coli prior to incubation for 4 days at 37 °C in tubes with and without sodium azide. Samples were collected every 24 hours, during four consecutive days, whereby the colony forming units (CFU) were counted on Columbia blood agar plates, and EtG was analyzed by LC-MS/MS. As expected, EtG degradation was observed when standard polypropylene tubes were used for the storage of contaminated samples. However, urine specimens collected in sodium azide tubes showed no or very limited bacterial growth and no EtG degradation. As a conclusion, sodium azide is useful to reduce bacterial growth of gram-negative and gram-positive bacteria. It inhibits the degradation of EtG by E. coli and can be used for the stabilization of EtG in urine samples.

Phosphatidylethanol (PEth) detected in blood for 3 to 12 days after single consumption of alcohol-a drinking study with 16 volunteers.

In most studies, the alcohol marker phosphatidylethanol (PEth) was used to differentiate social drinking from alcohol abuse. This study investigates PEth's potential in abstinence monitoring by performing a drinking study to assess the detection window of PEth after ingesting a defined amount of alcohol. After 2 weeks of abstinence, 16 volunteers ingested a single dose of alcohol, leading to an estimated blood alcohol concentration (BAC) of 1 g/kg. In the week after drinking, blood and urine samples were taken daily; in the second week, samples were taken every other day. PEth 16:0/18:1 and 16:0/18:2 were analyzed in blood by online-SPE-LC-MS/MS. Ethyl glucuronide and ethyl sulfate were determined in urine for abstinence monitoring. Prior to start of drinking, PEth 16:0/18:1 exceeded 30 ng/mL in blood samples of five volunteers despite the requested abstinence period. Positive PEth values resulted from drinking events prior to this abstinence period. After the start of drinking, maximum BACs were reached after 2 h with a mean of 0.80 ± 0.13 g/kg (range: 0.61-1.11 g/kg). PEth 16:0/18:1 increased within 8 h to maximum concentrations (mean: 88.8 ± 47.0 ng/mL, range: 37.2-208 ng/mL). After this event, PEth was detectable for 3 to 12 days with a mean half-life time of approximately 3 days. PEth has a potential in abstinence monitoring, since PEth could be detected for up to 12 days after a single drinking event. Further investigations are necessary, to establish cut-off levels for PEth as diagnostic marker for the determination of drinking habits like abstinence, social drinking, or risky alcohol consumption.

Improved detection of alcohol consumption using the novel marker phosphatidylethanol in the transplant setting: results of a prospective study.

Phosphatidylethanol (PEth) is a new, highly specific alcohol marker. The aim of this study was to assess its diagnostic value in the liver transplant setting. In 51 pre- and 61 post-transplant patients with underlying alcoholic liver disease PEth, ethanol, methanol, carbohydrate-deficient transferrin (CDT), and ethyl glucuronide in urine (uEtG) and hair (hEtG) were tested and compared with patients' questionnaire reports. Twenty-eight (25%) patients tested positive for at least one alcohol marker. PEth alone revealed alcohol consumption in 18% of patients. With respect to detection of alcohol intake in the preceding week, PEth showed a 100% sensitivity. PEth testing was more sensitive than the determination of ethanol, methanol, CDT or uEtG alone [sensitivity 25% (confidence interval (CI) 95%, 7-52%), 25% (7-52%), 21% (6-45%) and 71% (41-91%), respectively], or ethanol, methanol and uEtG taken in combination with 73% (45-92%). Specificity of all markers was 92% or higher. Additional testing of hEtG revealed alcohol consumption in seven patients, not being positive for any other marker. Phosphatidylethanol was a highly specific and sensitive marker for detection of recent alcohol consumption in pre- and post-transplant patients. The additional determination of hEtG was useful in disclosing alcohol consumption 3-6 months retrospectively.

Accelerated quantification of amphetamine enantiomers in human urine using chiral liquid chromatography and on-line column-switching coupled with tandem mass spectrometry.

Amphetamine (AM) is a powerful psychostimulant existing in two enantiomeric forms. Stereoselective analysis of AM in biosamples can assist clinicians and forensic experts in differentiating between abuse of illicitly synthesized racemic AM and ingestion of pharmaceutical AM formulations containing either S-AM or different proportions of the S- and R-enantiomers. Therefore, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying AM enantiomers in urine was newly developed. The method comprised dilution with water, followed by injection of the diluted sample onto an achiral C18 trapping column for purification and subsequent backflush elution to a chiral Lux 3 µm AMP LC column by means of a switching valve. An isocratic mobile phase of 25 % acetonitrile in 0.1 M aqueous ammonia was used for enantiomeric separation. Injection, cleanup, and backflush of the next sample were performed before the previous sample had eluted from the analytical column, thus enabling simultaneous enantioseparation of up to three samples within the analytical column. This novel chromatographic concept allowed for increased sample throughput by accelerating both the sample preparation and the LC analysis. Analyte detection was accomplished by electrospray ionization in positive ion mode and selected reaction monitoring using a triple-stage quadrupole mass spectrometer. The method was successfully validated through assessment of its linearity, lower limit of quantification, accuracy and precision, selectivity, matrix effect, carry-over, dilution integrity, and re-injection reproducibility. Linearity ranged from 0.05 to 25 mg/L for both enantiomers. Proof of the method included analysis of urine samples obtained from drug abusers and patients receiving an S-AM prodrug. Graphical Abstract Enantioselective determination of amphetamine in human urine using liquid chromatography with achiral-chiral column-switching and tandem mass spectrometry.

Application of phosphatidylethanol (PEth) in whole blood in comparison to ethyl glucuronide in hair (hEtG) in driving aptitude assessment (DAA).

For driving aptitude assessment (DAA), the analysis of several alcohol biomarkers is essential for the detection of alcohol intake besides psycho-medical exploration. In Switzerland, EtG in hair (hEtG) is often the only direct marker for abstinence monitoring in DAA. Therefore, the suitability of phosphatidylethanol (PEth) was investigated as additional biomarker. PEth 16:0/18:1 and 16:0/18:2 were determined by online-SPE-LC-MS/MS in 136 blood samples of persons undergoing DAA and compared to hEtG, determined in hair segments taken at the same time. With a PEth 16:0/18:1 threshold of 210 ng/mL for excessive alcohol consumption, all (n = 30) but one tested person also had hEtG values ≥30 pg/mg. In 54 cases, results are not in contradiction to an abstinence as neither PEth (<20 ng/mL) nor hEtG (<7 pg/mg) was detected. In eight cases, both markers showed moderate consumption. Altogether, PEth and hEtG were in accordance in 68 % of the samples, although covering different time periods of alcohol consumption. With receiver operating characteristic analysis, PEth was evaluated to differentiate abstinence, moderate, and excessive alcohol consumption in accordance with hEtG limits. A PEth 16:0/18:1 threshold of 150 ng/mL resulted in the best sensitivity (70.6 %) and specificity (98.8 %) for excessive consumption. Values between 20 and 150 ng/mL passed for moderate consumption, values <20 ng/mL passed for abstinence. As PEth mostly has a shorter detection window (2-4 weeks) than hEtG (up to 6 months depending on hair length), changes in drinking behavior can be detected earlier by PEth than by hEtG analysis alone. Therefore, PEth helps to improve the diagnostic information and is a valuable additional alcohol marker for DAA.

Phosphatidylethanol (PEth) in blood samples from "driving under the influence" cases as indicator for prolonged excessive alcohol consumption.

Phosphatidylethanol (PEth) is considered as specific biomarker of alcohol consumption. Due to accumulation after repeated drinking, PEth is suitable to monitor long-term drinking behavior. To examine the applicability of PEth in "driving under the influence of alcohol" cases, 142 blood samples with blood alcohol concentrations (BAC) ranging from 0.0-3.12‰ were analyzed for the presence of PEth homologues 16:0/18:1 (889 ± 878 ng/mL; range

N-Acetyltaurine as a novel urinary ethanol marker in a drinking study.

The forensic utility of N-acetyltaurine (NAcT) in urine as a marker for ethanol intake was examined. A HILIC-based liquid chromatography method for the mass spectrometric determination of NAcT, taurine, and creatinine in urine was developed and validated to investigate NAcT formation and elimination in a drinking study. Thereby, eight subjects ingested 0.66 to 0.84 g/kg alcohol to reach a blood alcohol concentration (BAC) of 0.8 g/kg. Blood and urine were taken every 1.5-2 h, during the first 8 h. NAcT and taurine levels were measured and corrected for the urine's dilution by normalization to a creatinine concentration of 1 mg/mL. For the determination of NAcT and taurine, uncorrected lower limits of quantitation (LLOQs) were at 0.05 µg/mL of urine. In the drinking study, NAcT proved to be an endogenous compound, which is present at a range of 1.0 to 2.3 µg/mL in urine of alcohol-abstinent subjects. Maximum NAcT concentrations were reached in samples taken 3 to 6 h after the start of drinking, whereby an upregulation in N-acetyltaurine could be found for all the subjects. The mean peak concentrations (c̅ max) of 14 ± 2.6 µg/mL (range 9-17.5 µg/mL) were reached. Within 24 h, the NAcT levels declined to endogenous concentrations. The detectability of NAcT was found to be slightly shifted compared to BAC: When BAC was not detectable anymore, NAcT levels were still elevated. After 24 h, when ethyl glucuronide (EtG) and ethyl sulfate (EtS) were still detectable, NAcT concentrations showed endogenous levels again. Positive NAcT results can be used as an indicator for recent alcohol consumption. A direct relationship between NAcT and taurine concentrations could not be found. Graphical abstract N-acetyltaurine concentrations for eight subjects during the first 24 h after an alcohol consumption of 0.8 g/kg.

Development of a rapid column-switching LC-MS/MS method for the quantification of THCCOOH and THCCOOH-glucuronide in whole blood for assessing cannabis consumption frequency.

The concentration of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THCCOOH) in whole blood is used as a parameter for assessing the consumption behavior of cannabis consumers. The blood level of THCCOOH-glucuronide might provide additional information about the frequency of cannabis use. To verify this assumption, a column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and direct quantification of free and glucuronidated THCCOOH in human whole blood was newly developed. The method comprised protein precipitation, followed by injection of the processed sample onto a trapping column and subsequent gradient elution to an analytical column for separation and detection. The total LC run time was 4.5 min. Detection of the analytes was accomplished by electrospray ionization in positive ion mode and selected reaction monitoring using a triple-stage quadrupole mass spectrometer. The method was fully validated by evaluating the following parameters: linearity, lower limit of quantification, accuracy and imprecision, selectivity, extraction efficiency, matrix effect, carry-over, dilution integrity, analyte stability, and re-injection reproducibility. All acceptance criteria were analyzed and the predefined criteria met. Linearity ranged from 5.0 to 500 µg/L for both analytes. The method was successfully applied to whole blood samples from a large collective of cannabis consumers, demonstrating its applicability in the forensic field.

Determination of fatty acid ethyl esters in dried blood spots by LC-MS/MS as markers for ethanol intake: application in a drinking study.

The forensic utility of fatty acid ethyl esters (FAEEs) in dried blood spots (DBS) as short-term confirmatory markers for ethanol intake was examined. An LC-MS/MS method for the determination of FAEEs in DBS was developed and validated to investigate FAEE formation and elimination in a drinking study, whereby eight subjects ingested 0.66-0.84 g/kg alcohol to reach blood alcohol concentrations (BAC) of 0.8 g/kg. Blood was taken every 1.5-2 h, BAC was determined, and dried blood spots were prepared, with 50 µL of blood, for the determination of FAEEs. Lower limits of quantitation (LLOQ) were between 15 and 37 ng/mL for the four major FAEEs. Validation data are presented in detail. In the drinking study, ethyl palmitate and ethyl oleate proved to be the two most suitable markers for FAEE determination. Maximum FAEE concentrations were reached in samples taken 2 or 4 h after the start of drinking. The following mean peak concentrations (c̅(max)) were reached: ethyl myristate 14 ± 4 ng/mL, ethyl palmitate 144 ± 35 ng/mL, ethyl oleate 125 ± 55 ng/mL, ethyl stearate 71 ± 21 ng/mL, total FAEEs 344 ± 91 ng/mL. Detectability of FAEEs was found to be on the same time scale as BAC. In liquid blood samples containing ethanol, FAEE concentrations increase post-sampling. This study shows that the use of DBS fixation prevents additional FAEE formation in blood samples containing ethanol. Positive FAEE results obtained by DBS analysis can be used as evidence for the presence of ethanol in the original blood sample.

Ethanol metabolites: their role in the assessment of alcohol intake.

BACKGROUND: Alcohol-related disorders are common, expensive in their course, and often underdiagnosed. To facilitate early diagnosis and therapy of alcohol-related disorders and to prevent later complications, questionnaires and biomarkers are useful. METHODS: Indirect state markers like gamma-glutamyl-transpeptidase, mean corpuscular volume, and carbohydrate deficient transferrin are influenced by age, gender, various substances, and nonalcohol-related illnesses, and do not cover the entire timeline for alcohol consumption. Ethanol (EtOH) metabolites, such as ethyl glucuronide, ethyl sulfate, phosphatidylethanol, and fatty acid ethyl esters have gained enormous interest in the last decades as they are detectable after EtOH intake. RESULTS: For each biomarker, pharmacological characteristics, detection methods in different body tissues, sensitivity/specificity values, cutoff values, time frames of detection, and general limitations are presented. Another focus of the review is the use of the markers in special clinical and forensic samples. CONCLUSIONS: Depending on the biological material used for analysis, ethanol metabolites can be applied in different settings such as assessment of alcohol intake, screening, prevention, diagnosis, and therapy of alcohol use disorders.

Influence of Gilbert's syndrome on the formation of ethyl glucuronide.

A drinking experiment with participants suffering from Gilbert's syndrome was performed to study the possible influence of this glucuronidation disorder on the formation of ethyl glucuronide (EtG). Gilbert's syndrome is a rather common and, in most cases, asymptomatic congenital metabolic aberration with a prevalence of about 5 %. It is characterized by a reduction of the enzyme activity of the uridine diphosphate glucuronosyltransferase (UGT) isoform 1A1 up to 80 %. One of the glucuronidation products is EtG, which is formed in the organism following exposure to ethanol. EtG is used as a short-term marker for ethyl alcohol consumption to prove abstinence in various settings. After 2 days of abstinence from ethanol and giving a void urine sample, 30 study participants drank 0.1 L of sparkling wine (9 g ethanol). 3, 6, 12, and 24 h after drinking, urine samples were collected. 3 hours after drinking, an additional blood sample was taken, in which liver enzyme activities, ethanol, hematological parameters, and bilirubin were measured. EtG and ethyl sulfate (EtS), another short-term marker of ethanol consumption, were determined in the urine samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS); creatinine was measured photometrically. In all participants, EtG and EtS were detected in concentrations showing a wide range (EtG: 3 h sample 0.5-18.43 mg/L and 6 h sample 0.67-13.8 mg/L; EtS: 3 h sample 0.87-6.87 mg/L and 6 h sample 0.29-4.48 mg/L). No evidence of impaired EtG formation was found. Thus, EtG seems to be a suitable marker for ethanol consumption even in individuals with Gilbert's syndrome.

Time dependence of elimination of different PEth homologues in alcoholics in comparison with social drinkers.

BACKGROUND: Phosphatidylethanol (PEth) is a direct marker of alcohol consumption, which has been known for almost 30 years. Each PEth molecule carries 2 fatty acids, which differ in chain length and degree of unsaturation. It is formed by means of phospholipase D in the presence of ethanol. Usually, this marker was used by quantification of the PEth homologue 16:0/18:1. The intention of this work was to get more information about the distribution and the quantity of the different PEth homologues. METHODS: Blood samples from 12 alcohol-dependent subjects were collected and analyzed during withdrawal therapy. For comparison, blood from 78 healthy social drinkers was also analyzed. PEth analysis was performed as follows: after liquid-liquid extraction, the homologues were separated on a Luna Phenyl Hexyl column, injected to an HPLC system (1100 system; Agilent) and identified by ESI-MS/MS (QTrap 2000; AB Sciex) using multiple reaction monitoring. RESULTS: PEth 16:0/18:1 is the major homologue comparing the area ratios of PEth homologues in blood samples from alcoholics. Additional prevalent homologues were PEth 16:0/18:2, 18:0/18:2, and 18:0/18:1. The homologues occurring in blood samples from alcoholics as well as from social drinkers were mostly the same, but differences among their distribution pattern were observed. CONCLUSIONS: In addition to the approach to quantitate the PEth homologue 16:0/18:1, this is a new and alternative proceeding for the differentiation between alcoholics and social drinkers using this alcohol consumption marker.

Cellular photo digital breathalyzer for monitoring alcohol use: a pilot study.

BACKGROUND: Monitoring alcohol use is important in numerous situations. Direct ethanol metabolites, such as ethyl glucuronide (EtG), have been shown to be useful tools in detecting alcohol use and documenting abstinence. For very frequent or continuous control of abstinence, they lack practicability. Therefore, devices measuring ethanol itself might be of interest. This pilot study aims at elucidating the usability and accuracy of the cellular photo digital breathalyzer (CPDB) compared to self-reports in a naturalistic setting. METHOD: 12 social drinkers were included. Subjects used a CPDB 4 times daily, kept diaries of alcohol use and submitted urine for EtG testing over a period of 5 weeks. RESULTS: In total, the 12 subjects reported 84 drinking episodes. 1,609 breath tests were performed and 55 urine EtG tests were collected. Of 84 drinking episodes, CPDB detected 98.8%. The compliance rate for breath testing was 96%. Of the 55 EtG tests submitted, 1 (1.8%) was positive. CONCLUSIONS: The data suggest that the CPDB device holds promise in detecting high, moderate, and low alcohol intake. It seems to have advantages compared to biomarkers and other monitoring devices. The preference for CPDB by the participants might explain the high compliance. Further studies including comparison with biomarkers and transdermal devices are needed.