Direct hollow fiber liquid phase membrane extraction and LC-MS/MS determination of non-steroidal anti-inflammatory drugs in fish

Abstract: NSAIDs (Non steroid anti-inflammatory drugs) have widely been found in STP (sewage treatment plant) effluents and surface water with different concentrations. However, the information concerning ecotoxicological risks, surface water and water living organisms is rather scarce. In this thesis, KET (ketoprofen), NAP (naproxen), DIC (diclofenac) and IBU (ibuprofen) were chosen as four model substances to study the bioaccumulation factor, the distribution, and the fate of the NSAIDs. A combination of HF-LPME (hollow fiber liquid-phase membrane extraction) and LC-MS/MS (liquid chromatography tandem mass spectrometry) was used to simultaneously extract and detect the NSAIDs in fish. For the freeze-dried fish tissue, this new analytical method showed an average enrichment factor of 3000 times. For water, the average enrichment factor was increased to 3700 times. The average R2 of the linearity were 0.9902, 0.9945, 0.9802 and 0.9890 for KET, NAP, DIC and IBU, respectively. Method detection limits for KET, DIC, NAP and IBU in the range of 1-3 ng/L. Moreover, this method could be successfully applied to detect the analytes in the real samples. For the wild cod fish, only NAP was found with a concentration of 26 ng/g (dry fish). For the wild rudd fish, two NSAIDs (78 ng/g of KET and 40 ng/g of NAP) were found. When the rudd fish was exposed to the NSAIDs, the four NSAIDs were determined in the range of 6-83 ng/g in the dry fish. Interestingly, for the exposed rudd, the concentrations of KET and DIC in dead rudd fishes were almost twice as that in the alive fish. The developed analytical methodology might be extended to be used to estimate the distribution or the fate of the four NSAIDs in other biota, animals or human beings.