A Highly Specific, Fully Validated Urinary Ethyl Glucuronide Analysis Using Solid Phase Extraction-Liquid...

Area of Science:

• Analytical Chemistry
• Forensic Toxicology
• Clinical Chemistry

Background:

• Ethyl glucuronide (EtG) is a direct metabolite of ethanol, detectable in urine days after alcohol consumption.
• Accurate EtG quantification is crucial for monitoring alcohol abstinence in treatment programs and in forensic investigations.
• Existing methods may require improvement in specificity and sensitivity for reliable EtG detection.

Purpose of the Study:

• To develop and validate a highly specific and selective liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for quantitative EtG determination in urine.
• To establish a reliable analytical tool for monitoring alcohol use, particularly in clinical and forensic settings.

Main Methods:

• Development and validation of an LC/MS/MS method for ethyl glucuronide (EtG) quantification in urine.
• Utilized propyl glucuronide (PrG) as an internal standard to enhance method selectivity.
• Employed solid-phase extraction (SPE) for sample cleanup and a C18 column for chromatographic separation.
• Validated parameters included selectivity, linearity, LOD, LOQ, precision, and recovery.

Main Results:

• The developed LC/MS/MS method demonstrated high specificity and selectivity for EtG determination.
• The limit of detection (LOD) was 90.8 ng/mL and the limit of quantification (LOQ) was 185.0 ng/mL.
• Intraday and interday precision were within acceptable limits, confirmed by HorRat values.
• The method showed excellent performance in real-world sample analysis.

Conclusions:

• The validated LC/MS/MS method provides a reliable and accurate solution for quantifying EtG in urine.
• This method is suitable for monitoring patients undergoing alcohol addiction treatment.
• The assay is applicable to both antemortem and postmortem toxicological investigations, aiding in alcohol use assessment.