Residues and Dissipation of Imidacloprid, Oxamyl, and Emamectin Benzoate in Greenhouse Grown Tomato Fruits and Their Influence on Lycopene Content

Abstract

The dissipation of oxamyl, emamectin benzoate, and imidacloprid pesticide residues in tomato fruits and their effect on its lycopene content were evaluated. The tested pesticides were applied according to the recommendation of the Egyptian Ministry of Agriculture for emamectin benzoate (Pasha EC 1.9%, 250 cm3/fedan), imidacloprid (Confidente SC 35%, 75 cm3/100L), and oxamyl (Vydate SL 24%, 3L/fedan). Pesticide residues in tomato fruits were analyzed using recently developed QuEChERS method coupled with HPLC. Recovery assays confirmed the validity and efficiency of QuEChERS with 101, 93, and 110% recovery for oxamyl, emamectin benzoate, and imidacloprid, respectively. The half-life (t1/2) values for oxamyl, emamectin benzoate, and imidacloprid in tomato fruits were 2.88, 3.12, and 3.46 days, respectively. After 12 days from application, the residues of oxamyl, emamectin benzoate, and imidacloprid in tomato fruits reached 1.0, 0.09, and 0.23 mg/kg, respectively. However, except imidacloprid, these residue values of oxamyl and emamectin benzoate were still above the maximal residue limit (MRL). In addition, the cumulative effects of imidacloprid and emamectin benzoate have significant inhibitory effects on the lycopene content compared to untreated tomato fruits.