Automated Sample Preparation for the Monitoring of Ethanol Metabolites in Urine by LC-MS/MS

Ethylglucuronide (EtG) and Ethylsulphate (EtS) are stable Phase II metabolites of ethanol, which can be detected in urine until several days after alcoholic beverage consumption. In this application note, we describe an LC-MS/MS method for the analysis of EtG and EtS in urine employing a simple, automated sample preparation methodology using a liquid handling-based automation system. Automation of the sample preparation for analysis by LCMS/MS has the potential to increase throughput, reduce active bench time, and minimize the opportunity for human error. Our method enabled the quantification of EtG and EtS over a large concentration range, spanning from 0.5X to 10X the cut-off value, with accuracies ranging from 97-104%, and CV less than 4% taking into account both sample preparation and LC-MS/ MS analysis.