MULTIRESIDUE METHOD FOR PESTICIDES IN AÇAÍ PULP USING A MODIFIED QuEChERS METHOD AND UHPLC-MS/MS

The northern region of Brazil, particularly the states of Par & aacute; and Amazonas, concentrates the majority of a & ccedil;ai national production. Considering the possible use of pesticides in this species, this study aimed to develop a comprehensive method for the multiresidue determination of pesticides in a & ccedil;ai pulp, using a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method with analysis by ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). Various parameters of extraction were investigated, and the method was successfully validated. Analysis by UHPLC-MS/MS provided high selectivity and sensitivity. The main modification to the original QuEChERS method was the use of the C18 adsorbent associated with primary secondary amine (PSA) in the clean-up step by dispersive solid phase extraction (d-SPE). The method was validated for 83 compounds, showing adequate accuracy (70 to 120%) and precision (RSD <= 20%). The method limits of quantification, established by recovery tests, ranged from 5 to 25 mu g kg-1. The method limits of detection were from 1.5 to 7.5 mu g kg-1. The method was applied to commercial samples of a & ccedil;ai pulp, and no pesticide residues were detected. The proposed method proved to be fast, efficient and suitable for multiresidue determination of pesticides in a & ccedil;ai pulp in routine analysis.