Metabolites of the aquatic pollutant diclofenac in fish bile.

The uptake and metabolism of anti-inflammatory drug diclofenac (DCF) was studied by exposing rainbow trout (Oncorhynchus mykiss) to DCF intraperitoneally, and via water at concentration of 1.7 μg L(-1). The bile was collected and the formed metabolites were identified. The identification was based on the exact mass determinations by a time-of-flight mass analyzer and on the studies of fragments and fragmentation patterns of precursor ions by an ion trap mass analyzer. The main metabolites found were acyl glucuronides of hydroxylated DCFs. In addition, one ether glucuronide of hydroxylated DCF was found. Also, unmetabolized DCF was detected in the bile. The total bioconcentration factors (BCF(total-bile) for DCF and its metabolites) in rainbow trout bile, varied between individuals and was roughly estimated to range from 320 to 950. These findings suggest that fish living downstream the wastewater treatment plants (WWTPs) and which are chronically exposed to the drug may accumulate the drug and its metabolites in the bile.