Urine tested positive for ethyl glucuronide and ethyl sulfate after the consumption of yeast and sugar

Abstract

Background To an increasing degree, EtG and EtS are routinely used for the proof of abstinence for purposes of traffic, occupational, addiction and social medicine. This routine use demands further investigations on the sensitivity and specificity of these analytes and the examination of possible genesis of positive EtG and EtS concentrations even without the consumption of ethanol. In vivo fermentation with consecutive formation of EtG and EtS was addressed by experiments with yeast products. Methods Two experiments with baker's yeast and brewer's yeast tablets were performed. The ethanol concentrations in urine of the 2 and 4 volunteers, respectively, were detected by HS-GC-FID, EtG and EtS analysis was performed by LC–ESI-MS/MS, and the creatinine concentration was determined using a method based on the Jaffé reaction. Results and conclusions After the consumption of baker's yeast the maximum concentrations of EtG and EtS normalised to creatinine were found to be 0.67 and 1.41 mg/L, respectively, and therefore clearly above the commonly applied cut-off value for the proof of abstinence of 0.1 mg/L. In contrast, in this study the, uptake of yeast tablets did not result in a detection of EtG and EtS in urine.