Determinação de resíduo de bifentrina em banana após a colheita e na água de lavagem

Abstract

In banana farming, the use of bags impregnated by insecticides and the washing of bunches are techniques that aim at maintaining the quality of fruits. This study aimed to monitor, by Gas Chromatography (GC) coupled with Mass Spectrometry (MS), bifenthrin residue in washed and unwashed bananas, as well as in the fruit washing water. From the emission until the harvest, the bunches were protected with bags impregnated with bifenthrin at 1.0 g kg-1, which were removed after harvest for fruit dropping and washing or not bunches in tanks with water, detergent and aluminum sulfate. The Quick, Easy, Cheap, Effective, Rugged, Safe Method - QuEChERS and liquid-liquid extraction with the low temperature partition method were used to extract bifenthrin residue from fruits at harvest point and ripe, and from water, respectively. Bifenthrin recovery percentages were 88.16%, 103.4% and 89.32% in peel, pulp and in peel + pulp, respectively, in compliance with Brazilian legislation. At the harvest point, 0.060 mg kg-1 and 0.010 mg kg-1 were detected in peel and in peel + pulp of washed fruits, respectively. When unwashed, bifenthrin concentration in peel was 0.31 mg kg-1 and 0.16 mg kg-1 in peel + pulp. No bifenthrin residue was detected in pulp, regardless of maturation stage and washing, as well as in the washing water. In mature unwashed fruits, 0.10 mg kg-1 and 0.040 mg kg-1 of bifenthrin were detected in peel and in peel + pulp, respectively. Washing does not eliminate the residues, but reduces bifenthrin residue in fruit peel at the harvest point; when ripe, only unwashed fruits showed presence of bifenthrin residue.