Ethyl Glucuronide and Ethyl Sulfate, Urine

Laboratory assay overview

Ethylglucuronide (EtG) and Ethylsulfate (EtS) are metabolites of ethanol. While EtG has been used as a long-term biomarker in urine testing for more than 7 years, EtS has more recently been incorporated into testing programs. Scientific literature indicates that EtG may be detectable for up to 80 hours and that EtS may be detectable for 24 hours or more after ethanol ingestion - depending on cutoff, metabolism, and usage patterns. Under certain conditions, in-vitro (outside of the body, in the specimen container) formation of EtG may also occur when certain bacteria and ethanol or ethanol-producing bacteria are both present in a urine specimen. No published reports of in-vitro synthesis of EtS exist, however, even under the same conditions in which EtG may be synthesized in-vitro. EtS is typically present in urine at a lower concentration than EtG, although the ratio of EtG to EtS varies significantly between individual donors. In order to be reported positive for EtG, Quest Diagnostics’ clinical reporting criteria require that EtS be present in a specimen at a minimum concentration of 100 ng/mL whenever EtG is present at a concentration greater than or equal to 500 ng/mL. As with EtG, the presence of EtS in a urine specimen does not establish the source of the ethanol containing product and the possibility of "incidental exposure" and post-collection specimen changes needs to be considered when interpreting results. EtG and EtS testing, as with any controlled substance testing, measure only the presence and concentration of EtG (or EtS) in a given urine specimen. Quest Diagnostics recommends clinical correlation and/or healthcare provider review when interpreting EtG and EtS results.

Quest Diagnostics population reference ranges

Quest Diagnostics calculates these statistical intervals for this specific assay and demographic group, not as universal optimal targets.