Fungicide dissipation kinetics and dietary exposure risk assessment in squash fruit and leaf

Dissipation behavior and dietary exposure risk assessment of four pesticides (dimethomorph, mandipropamid, myclobutanil, and metalaxyl) were studied in fruits and leaves of squash grown under greenhouse conditions. Squash fruit and leaf samples were collected randomly at 0, 3, 5, 7, and 14 days after the last pesticide application. The analytical method was set up using ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). The quick, easy, cheap, effective, rugged, and safe method (QuEChERS) was performed for sample preparation. Recovery rates at two spiked levels (0.01 and 0.1 mg/kg) were in the range of 76.4–101.9% for the analyzed pesticides and their relative standard deviations were ≤ 4%.Pesticide half-lives were 2.1 and 4.9 days for dimethomorph, 4.6 and 8.1 days for mandipropamid, 4.7 and 8.2 days for myclobutanil, and 2.7 and 5 days for metalaxyl in squash fruit and leaf, respectively. Regarding total surveyors, hazard quotient values for squash fruit and leaf were ≤ 1.03 × 10 − 3 and ≤ 2.39 × 10 − 3 , respectively. These values in the case of true consumers were ≤ 3.14 × 10 − 3 and ≤ 3.91 × 10 − 1 , respectively.