Multi-residue analysis and probabilistic health risk assessment of pesticides in papaya and melon using QuEChERS–HPLC-MS/MS

A QuEChERS-based sample preparation technique, coupled with HPLC–MS/MS analysis using dynamic multiple reaction monitoring (dMRM), was developed for the precise determination of pesticide residues in papaya and melon samples from Iran. The method showed good linearity over the 0.01–0.5 mg L⁻¹ range, with coefficients of determination (R²) > 0.99. Limits of quantification ranged from 0.004 mg L⁻¹ (buprofezin) to 0.051 mg L⁻¹ (indoxacarb). Method accuracy and precision were evaluated at two fortification levels, yielding recoveries of 70.0–122.4% and RSDs below 20.0% (≤ 15.0% for the vast majority of analytes) for all monitored pesticides, thereby fully complying with the European SANTE criteria. All pesticide residues detected in papaya samples were below the national maximum residue limits (MRLs). In contrast, fourteen pesticides in melon samples exceeded permissible limits, including eight insecticides (sulfotep, imidacloprid, diazinon, phosalone, acetamiprid, pymetrozine, pirimiphos-methyl, dimethoate), four fungicides (carbendazim, iprodione, propiconazole, thiabendazole), one acaricide (fenpyroximate), and one herbicide (fenoxaprop-ethyl). Dietary exposure assessment indicated potential long-term health risks for adults and children, with a total carcinogenic risk of 2.93 × 10⁻⁶ for melon consumption. Extending pre-harvest intervals and reducing pesticide application rates may mitigate contamination risks.