Phase II pharmaceutical metabolites acetaminophen glucuronide and acetaminophen sulfate in wastewater

Environmental context. Excretion of pharmaceuticals and their metabolites by humans and animals, flushing unused pharmaceuticals and inadequate water treatment result in the occurrence of these chemicals as pollutants in wastewater, surface water and drinking water. In this research, the pharmaceutical agent acetaminophen (paracetamol, Tylenol) and its glucuronide and sulfate metabolites were examined as a model system for monitoring wastewater influent and effluent. The true risk to ecosystems and humans from the occurrence of pharmaceuticals in our water supply can only be estimated if accurate concentrations of parent pharmaceutical chemicals as well as their metabolites are measured.

Abstract. An analytical method was developed to separately determine acetaminophen and its Phase II metabolites, acetaminophen glucuronide and acetaminophen sulfate, from wastewater in a single extract. The method developed will serve as a model for screening for the presence of other non-steroidal pharmaceutical compounds and their Phase II metabolites in wastewater. Acetaminophen glucuronide was not present in the wastewater influent tested to verify the analytical protocol, whereas concentrations of acetaminophen and acetaminophen sulfate in the influent were reproducible over time. A Phase I metabolite, p-aminophenol, was also determined to occur in the wastewater influent. Concentrations of the analytes-of-interest, detected in effluent samples collected after secondary treatment, but before UV treatment, were highly variable and were undetectable after UV treatment before release to surface water.