Occurrence of postmortem production of ethylene glycol and propylene glycol in human specimens

We previously established a sensitive gas chromatography–mass spectrometry method for analysis of ethylene glycol (EG), propylene glycol (PG), and diethylene glycol (DEG), and disclosed the presence of appreciable amounts of EG, PG, and DEG in fresh whole blood and urine specimens obtained from nonoccupational healthy humans. These results led us to analyze EG and PG in specimens taken from three human cadavers. EG and PG concentrations in the postmortem blood and solid tissues were much higher than those found in fresh whole blood; their concentrations in many postmortem specimens were more than tenfold those in fresh whole blood specimens, suggesting the postmortem production of EG and PG. Therefore, we examined the time courses of EG and PG concentrations in blood specimens in the absence and presence of saprogenic blood (10 % volume) and/or glucose (3 mg/ml) in vitro, which were left at room temperature for 7 days. EG concentration in fresh blood without any addition decreased slightly during the 7 days. EG concentration in the blood with addition of glucose, and PG concentrations in the blood with and without addition of glucose did not change appreciably during the 7 days. EG and PG concentrations in the blood after addition of 10 % saprogenic blood increased 3.1-fold and 3.5-fold after 7 days, respectively; those after addition of saprogenic blood plus glucose increased 9.1-fold and 11.9-fold after 7 days, respectively. These results show that microorganisms present in the saprogenic blood caused the postmortem production of EG and PG, and the addition of glucose further enhances the EG and PG concentrations, probably acting as the substrate for glycol production by the microorganisms. To our knowledge, this is the first report to describe postmortem production of EG and PG in human specimens.