Understanding the magnitude of emergent contaminant releases through target screening and metabolite identification using high resolution mass spectrometry: Illicit drugs in raw sewage influents

• A total of 54 phase I and II metabolites of illicits were reported.
• Data dependent scan and targeted MS2 were explored for confirmation of metabolites.
• %mol fraction of each identified metabolite was reported.

A QExactive Orbitrap was used for the identification of phase I and II transformation products (TPs) of illicit drugs in raw sewage influents. Two operating modes (targeted MS2 and Data-dependent screening) were used for data acquisition. Even though, data-dependent scan is a faster route towards the potential identification of metabolites, it suffered from its limitation to provide enough data points across the chromatographic peak during the MS2 cycle in contrast to targeted MS2. Therefore, the later technique was implemented as the method of choice in this study for the positive confirmation and quantitation of TPs (n = 54). The vast majority of the identified TPs were products of phase I transformation reactions, with the latter being more prevalent in the nature. Estimated mole fractions showed that for a large number of the analytes, TPs must also be monitored in order to fully understand their environmental fate and calculate potential consumption.