SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

A35
ETHYLGLUCRONIDE ANALYSIS IN URINE BY LIQUID CHROMATOGRAPHY WITH
TANDEM MASS SPECTROMETRY
Michael Feldman*' \ KC Van Home 2 , Zhichun Liu 2 , Patrick Bennete, David J. Kuntz!. lNorthwest
Toxicology, a division ofLab One, Salt Lake City, UT 84124, USA and 2Tandem Labs, Salt Lake City, UT
84124, USA
~-D-ethylglucuronide (EtG) is a metabolite of ethanol which is formed by the conjugation of ethanol with
activated glucuronic acid in the presence of membrane-bound mitochrondrial UDP glucuronyl transferase.
EtG is produced at approximately 0.02-0.06% of an ingested dose. EtG is stable, water-soluble and can be
detected in urine and can be detected for up to three days following ethanol consumption. Urine ethanol
levels are normally detected only for several hours, thus making EtG a unique metabolite for monitoring
abstinence of alcoholics in alcohol treatment programs.
Urine samples for analysis are prepared by the direct addition of 100 IJ,L of urine with 400 IJ,L of internal
standard (EtG-D5) in water into the liquid sample vial. No extraction is required. The HPLC used in the
analysis is a Shimadzu SCL-IOA with a Phenomenex Luna 31J,m column with a mobile phase consisting of
methanol, water and formic acid with a flow rate of 400lJ,Llminute. The mass spectrometer is a Sciex API­
3000 using a Turbo Ion Spray Source in the negative ion mode. Quadrupole 1 was set to pass the 221 and
226 ions for EtG and EtG-D5, respectively. Transition ions of 75 (quantitation) and 85 (qualifier) were
monitored for each compound.
The assay was linear between 40 nglmL to 10,000 ng/mL with a cutoff established at 100 ng/mL with a
Limit of Detection and Limit of Quantitation of 40 ng/mL. Precision was determined with %CV of less
than 1 % between the concentrations of 40-150 ngimL. The %CV between runs was determined to be less
than 7%. Data from dosing studies, including incidental exposure, will be presented.
Keywords: Ethylglucuronide, Ethanol
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