Validation of the NSAID in vitro assay for biomonitoring of NSAID activities in surface waters: final report
In: Texte 2020, 167
In: Ressortforschungsplan of the Federal Ministry for the Enviroment, Nature Conservation and Nuclear Safety
The NSAID in vitro assay developed as a tool for environmental monitoring of pharmaceutical effects was validated for its suitability to detect COX inhibitor activity in surface water. A standard operation procedure based on solid phase extraction of aqueous samples was established by modifying a sampling protocol for the detection of estrogens with the aim to stabilize NSAIDs in the samples. In addition, the sensitivity of the NSAID in vitro assay was improved by minimizing matrix effects and improving the stability of the substrate arachidonic acid. The validation characteristics linearity, measurement range, accuracy, precision and limit of detection were evaluated. The test procedure was used for measuring 39 surface water samples taken at EU Watch List sampling sites in 14 EU member states and 4 Swiss cantons between autumn 2017 to spring 2018. Diclofenac equivalents measured by the NSAID in vitro assay were compared with data obtained by chemical analysis (LC-MS/MS) of diclofenac and other COX-inhibitors.