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An evaluation of the DRI‐ETG EIA method for the determination of ethyl glucuronide concentrations in clinical and post‐mortem urine
Author(s) -
Turfus Sophie C.,
Vo Tu,
Niehaus Nadia,
Gerostamoulos Dimitri,
Beyer Jochen
Publication year - 2013
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.414
Subject(s) - ethyl glucuronide , chromatography , immunoassay , urine , chemistry , detection limit , glucuronide , quantitative analysis (chemistry) , mass spectrometry , liquid chromatography–mass spectrometry , tandem mass spectrometry , medicine , alcohol , biochemistry , antibody , alcohol consumption , immunology
A commercial enzyme immunoassay for the qualitative and semi‐quantitative measurement of ethyl glucuronide (EtG) in urine was evaluated. Post‐mortem (n=800), and clinical urine (n=200) samples were assayed using a Hitachi 902 analyzer. The determined concentrations were compared with those obtained using a previously published liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method for the quantification of EtG and ethyl sulfate. Using a cut‐off of 0.5 µg/ml and LC‐MS/MS limit of reporting of 0.1 µg/ml, there was a sensitivity of 60.8% and a specificity of 100% for clinical samples. For post‐mortem samples, sensitivity and specificity were 82.4% and 97.1%, respectively. When reducing the cut‐off to 0.1 µg/ml, the sensitivity and specificity were 83.3% and 100% for clinical samples whereas for post‐mortem samples the sensitivity and specificity were 90.3 % and 88.3 %, respectively. The best trade‐offs between sensitivity and specificity for LC‐MS/MS limits of reporting of 0.5 and 0.1 µg/ml were achieved when using immunoassay cut‐offs of 0.3 and 0.092 µg/ml, respectively. There was good correlation between quantitative results obtained by both methods but analysis of samples by LC‐MS/MS gave higher concentrations than by enzyme immunoassay (EIA), with a statistically significant proportional bias (P<0.0001, Deming regression) for both sample types. The immunoassay is reliable for the qualitative and semi‐quantitative presumptive detection of ethyl glucuronide in urine. Copyright © 2012 John Wiley & Sons, Ltd.