title: Accurate assignment of ethanol origin in postmortem urine: liquid chromatographic-mass spectrometric determination of serotonin metabolites.
abstract: Toxicological examination of fatal aviation accident victims routinely includes analysis of ethanol levels. However, distinguishing between antemortem ingestion and postmortem microbial formation complicates all positive ethanol results. Development of a single analytical approach to determine concentrations of 5-hydroxytryptophol (5-HTOL) and 5-hydroxyindole-3-acetic acid (5-HIAA), two well-known metabolites of serotonin, has provided a convenient, rapid and reliable solution to this problem. Antemortem ethanol leads to an elevation in the 5-HTOL/5-HIAA ratio for 11-19 h after acute ingestion. The liquid-liquid extracts of postmortem urine samples were subjected to liquid chromatography-mass spectrometry (LC-MS) for the simultaneous quantitation of these two analytes, yielding detection limits of 0.1 ng/ml for each. Examination of the 5-HTOL/5-HIAA ratio was undertaken for 44 urine samples known to be antemortem ethanol-positive or antemortem ethanol-negative. Recent ethanol ingestion was conveniently and accurately separated using a 5-HTOL/5-HIAA ratio of 15 pmol/nmol, a value previously suggested using human volunteers. All 21 ethanol-negative postmortem samples were below this cutoff, while all 23 ethanol-positive postmortem samples were above this cutoff. Thus, we recommend the employment of this cutoff value, established using this straightforward LC-MS procedure, to confirm or deny recent antemortem ethanol ingestion in postmortem urine samples.
authors.affiliation: Federal Aviation Administration, Civil Aerospace Medical Institute, AAM-610, Oklahoma City, OK 73169-6901, USA. r.d.johnson@faa.gov
authors.forename: R D
authors.initials: RD
authors.lastname: Johnson
authors.forename: R J
authors.initials: RJ
authors.lastname: Lewis
authors.forename: D V
authors.initials: DV
authors.lastname: Canfield
authors.forename: C L
authors.initials: CL
authors.lastname: Blank
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D000431:Ethanol / Q000652:urine*; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine*; D006917:Hydroxytryptophol / Q000652:urine*; D013058:Mass Spectrometry / Q000379:methods*; D011180:Postmortem Changes; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D006917:Hydroxytryptophol; D000431:Ethanol; D006897:Hydroxyindoleacetic Acid