Modified QuEChERS/UPLC-MS/MS method to monitor triclosan, ibuprofen, and diclofenac in fish Pseudoplatystoma magdaleniatum

Abstract

The objective of the study was to develop a simple, fast, and sensitive analytical method for the extraction and quantification of ibuprofen, diclofenac, and triclosan in the muscle of the striped catfish Magdalena (Pseudoplatystoma magdaleniatum), a species of fish emblematic of the main rivers of Colombia (Magdalena and Cauca) that is critically endangered. The extraction method used was QuEChERS, the cleaning method for the removal of co-extracted fats and lipids was freezing, and quantification was performed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was validated according to the performance requirements of Appendix F of AOAC. The results showed that the method is accurate and reproducible; the extraction procedure is fast and can be performed on a small-sample aliquot. The value of LOQ in fish tissue was 20 μg/kg dry weight and LOD of 2.775 for diclofenac; 1.163 for ibuprofen; and 1.214 for triclosan. RSDs for repeatability and intermediate precision were < 20.3%. Linearity has correlation coefficients (r) greater than 0.99 for the range of 20–400 μg/kg. Recoveries of 63–112%, 75–102%, and 62–113% for triclosan, diclofenac, and ibuprofen, respectively, were obtained. The method was applied to fish in the Magdalena and Cauca rivers with positive results, finding the polluting triclosan in the fish muscle at concentrations of up to 54.67 μg/kg dry weight, while ibuprofen and diclofenac were not detected in the matrices analyzed. This is the first freshwater fish research in Colombia.