title: Ethyl glucuronide and ethyl sulphate determination in serum by liquid chromatography-electrospray tandem mass spectrometry.
abstract: BACKGROUND
  Ethyl glucuronide (EtG) and ethyl sulphate (EtS) are two ethanol metabolites that can be detected in serum up to 8 h after ethanol elimination. Their presence is therefore indicative of recent ethanol consumption in case of delayed sampling after an event (e.g. car crash).
  
  
  METHODS
  A LC-ESI-MS-MS method for the determination of EtG and EtS in serum was developed and validated. Two product ions together with the parent ions were monitored for identification. Pentadeuterated-EtG was used as internal standard.
  
  
  RESULTS
  Excellent linearity for EtG (from 0.22 to 45 micromol/l) and EtS (from 0.40 to 80 micromol/l) was observed (r(2)>or=0.9998). LOD and LLOQ were 0.04 and 0.20 micromol/l for EtG and 0.08 and 0.40 micromol/l for EtS, respectively. Accuracy (bias) and precision (relative standard deviation), studied at four different quality control levels, were always better than 7%. Matrix effects were found to be negligible. The method was applied to several samples obtained from known alcoholics and social drinkers.
  
  
  CONCLUSIONS
  A sensitive and specific determination of EtG and EtS in serum samples was achieved despite a simple and fast sample preparation. To our knowledge, this is the first fully validated method for the simultaneous determination of the two alcohol metabolites in serum.
authors.affiliation: Department of Legal Medicine and Public Health, University of Pavia, Via Forlanini 12-27100 Pavia, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Morini
authors.forename: Lucia
authors.initials: L
authors.lastname: Politi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Zucchella
authors.forename: Aldo
authors.initials: A
authors.lastname: Polettini
mesh_terms: D000428:Alcohol Drinking / Q000097:blood*; D000437:Alcoholism / Q000097:blood* / Q000175:diagnosis; D002853:Chromatography, Liquid; D005965:Glucuronates / Q000097:blood*; D006801:Humans; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013463:Sulfuric Acid Esters / Q000097:blood*
chemical_list: D005965:Glucuronates; D013463:Sulfuric Acid Esters; C093924:ethyl glucuronide; C011612:diethyl sulfate