Determination of Sulfonamides in Fish Using a Modified QuEChERS Extraction Coupled with Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

In the present work, an improved QuEChERS (quick, easy, cheap, effective, rugged and safe) protocol coupled with ultra-performance liquid chromatography-tandem mass spectrometry analytical method was developed and validated for determination of trace sulfonamides residues in fish tissues. The QuEChERS protocol was modified in terms of extraction solvent, as well as a graphene-based dispersive solid-phase cleanup procedure. Some extraction conditions such as solvent, acidity, and the amount of graphene sorbent were evaluated. The matrix effect related to the QuEChERS extraction from fish tissues was studied and compared with conventional QuEChERS protocol. The target analytes were quantified by a triple-quadrupole linear ion-trap mass spectrometer in multiple-reaction monitoring mode. The matrix-matched calibration curves were performed at seven concentration levels and good linear relationship (R2 > 0.999) was observed within the range of 0.5–200 μg kg −1. Recoveries of the spiked samples ranged between 70.7 and 100.9 % with relative standard deviation lower than 9.2 %. The limits of quantification were between 2.62 and 9.03 μg kg−1. The method was successfully applied to the analysis of real samples.