title: Liquid Chromatography-Tandem Mass Spectrometry Assay to Detect Ethyl Glucuronide in Human Fingernail: Comparison to Hair and Gender Differences.
abstract: Over the past decade, the use of hair specimens for the long-term detection of the alcohol biomarker ethyl glucuronide has been increasing in popularity and usage. We evaluated the usefulness of fingernail clippings as a suitable alternative to hair for ethyl glucuronide detection. A liquid chromatography-tandem mass spectrometry method for the detection of ethyl glucuronide in fingernail clippings was fully validated and used to analyze the hair and/or fingernail specimens of 606 college-aged study participants. The limit of detection was 2 pg/mg, the limit of quantitation was 8 pg/mg and the method was linear from 8 to 2000 pg/mg. Intra- and inter-assay imprecision studies at three different concentrations (20, 40, 200 pg/mg) were all within 7.8% and all intra- and inter-assay bias studies at these levels were within 115.1% of target concentration. Ethyl glucuronide levels in fingernail (mean = 29.1 ± 55.6 pg/mg) were higher than ethyl glucuronide levels in hair (mean = 9.48 ± 22.3 pg/mg) and a correlation of the matched pairs was observed (r= 0.552,P< 0.01,n= 529). Evaluating each gender separately revealed that the correlation of male fingernail to male hair was large and significant (r= 0.782,P< 0.01,n= 195) while female hair to female fingernail was small yet significant (r= 0.249,P< 0.01,n= 334). The study results demonstrated that fingernail may be a suitable alternative to hair for ethyl glucuronide detection and may be the preferred sample type due to the lack of a gender bias.
authors.affiliation: United States Drug Testing Laboratories, Inc., Des Plaines, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Jones
authors.affiliation: United States Drug Testing Laboratories, Inc., Des Plaines, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Jones
authors.affiliation: United States Drug Testing Laboratories, Inc., Des Plaines, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Plate
authors.affiliation: United States Drug Testing Laboratories, Inc., Des Plaines, USA.
authors.forename: Douglas
authors.initials: D
authors.lastname: Lewis
authors.affiliation: Center for Addiction and Behavioral Health Research, University of Wisconsin-Milwaukee, Milwaukee, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Fendrich
authors.affiliation: Center for Addiction and Behavioral Health Research, University of Wisconsin-Milwaukee, Milwaukee, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Berger
authors.affiliation: Center for Addiction and Behavioral Health Research, University of Wisconsin-Milwaukee, Milwaukee, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fuhrmann
keywords: Alcohol; Biomarkers; Ethyl Glucuronide; Fingernail; Hair; LC-MS/MS; Liquid Chromatography-Tandem Mass Spectrometry