title: N-Acetyltaurine as a novel urinary ethanol marker in a drinking study.
abstract: 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.
authors: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, 3012, Bern, Switzerland. marc.luginbuehl@irm.unibe.ch.
authors: Marc
authors: M
authors: Luginbühl
authors: Laboratory of Toxicology, University of Ghent, FFW - 4th Floor, Ottergemsesteenweg 460, 9000, Ghent, Belgium.
authors: Sofie
authors: S
authors: Rutjens
authors: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, 3012, Bern, Switzerland.
authors: Stefan
authors: S
authors: König
authors: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
authors: Julien
authors: J
authors: Furrer
authors: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, 3012, Bern, Switzerland.
authors: Wolfgang
authors: W
authors: Weinmann
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000097:blood / Q000652:urine*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D000067401:Blood Alcohol Content; D002853:Chromatography, Liquid / Q000379:methods; D000431:Ethanol / Q000097:blood / Q000652:urine*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D053719:Tandem Mass Spectrometry / Q000379:methods; D013654:Taurine / Q000031:analogs & derivatives* / Q000097:blood / Q000652:urine; D016482:Urinalysis / Q000379:methods; D055815:Young Adult
chemical_list: D015415:Biomarkers; D000067401:Blood Alcohol Content; C083076:acetyltaurine; D013654:Taurine; D000431:Ethanol
keywords: Abstinence monitoring; Alcohol marker; LC-MS/MS; N-Acetyltaurine; Taurine; Urine analysis