Abstract: A quick, easy, cheap, effective, rugged, and safe (QuEChERS) combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for determination of 9 herbicide residues (prometryn, acetochlor, butachlor, quinclorac, bensulfuron methyl, metsulfuron methyl, atrazine, linuron and bentazone) in aquatic products. Detection was carried out in the positive ion mode with multiple reaction monitoring and the external standard method was used for quantification. The matrix effects in the determination of the nine herbicides and the factors influencing?them were analyzed. The results showed that good linearity was observed for quinclorac and linuron in the concentration range of 1.00–100 ng/mL and for seven other herbicides in the concentration range of 0.50–100 ng/mL with correlation coefficients above 0.99. The limits of detection (LODs) and limits of quantitation (LOQs) for all herbicides were in the ranges of 0.20–0.50 and 0.50–1.50 μg/kg, respectively. The average recoveries of the herbicides spiked into blank samples of Penaeus orientalis, Cyprinus carpio, Carassius auratus and Aristichthys nobilis were 84.33%–116.37% (n = 6), and the precision expressed as relative standard deviation (RSD) was 0.80%–13.81% (n = 6). This method could be applied to determine the 9 herbicide residues in aquatic products. The type and mass of matrix and herbicide concentration influenced the matrix effect. Quinclorac, bensulfuron methyl and metsulfuron methyl showed strong matrix enhancement effects in P. orientalis and C. carpio, while butachlor, acetochlor, linuron, bentazone and atrazine showed matrix inhibition effects in all four aquatic products. The matrix calibration curve should be used to reduce the matrix effects to ensure the accuracy in the detection of herbicide residues in aquatic products.

Key words: QuEChERS; ultra-high performance liquid chromatography-tandem mass spectrometry; aquatic products; herbicides; matrix effects