Development and validation of LCMS method for determination of Ethyl Glucuronide (EtG) in urine

Abstract Background Ethyl glucuronide (EtG) is a phase II metabolite of ethanol and is an upcoming biomarker for recent alcohol intake. Monitoring of alcohol intake in case of alcohol-dependent syndrome is very useful for early intervention and preventing harmful effects. EtG has also been identified as a very useful marker in differentiating antemortem ingestion of alcohol from postmortem production of alcohol. This study was undertaken with an objective of developing a sensitive and specific method for determination of EtG in urine. Methods Triple quadruple Liquid Chromatography (LC)-Mass Spectrometry (MS) with Electrospray Ionization (ESI) negative mode has been used for developing the multiple reaction monitoring method by using the Polaris 3 C 18-Ether analytical column. A simple sample preparation method was adopted using the Bond Elute Plexa PAX SPE cartridge. The developed method was also tested on actual urine samples from 15 individuals after consumption of 60 and 90 ml of whiskey at different time intervals. Results A simple method was developed for determination of EtG in urine, with a sensitivity of 100 ppb and a recovery of 75%. Validation of the method on urine samples revealed that EtG could be detected for up to 18 h in individuals who ingested 60 ml of whiskey and up to 24 h in those who ingested 90 ml of whiskey. Conclusion The simple method was developed for determination of EtG in urine and validated on actual urine samples. This method can now be used in aircraft accident investigation to differentiate postmortem production of alcohol, and the method is also a very useful tool to monitor Alcohol dependent Syndrome (ADS) cases.