Effectiveness of Commercial and Homemade Washing Agents in Removing Pesticide Residues on and in Apples

Removal of pesticide residues from fresh produce is important to reduce pesticide exposure to humans. This study investigated the effectiveness of commercial and homemade washing agents in the removal of surface and internalized pesticide residues from apples. Surface-enhanced Raman scattering (SERS) mapping and liquid chromatography tandem mass spectrometry (LC–MS/MS) methods were used to determine the effectiveness of different washing agents in removing pesticide residues. Surface pesticide residues were most effectively removed by sodium bicarbonate (baking soda, NaHCO3) solution when compared to either tap water or Clorox bleach. Using a 10 mg/mL NaHCO3 washing solution, it took 12 and 15 min to completely remove thiabendazole or phosmet surface residues, respectively, following a 24 h exposure to these pesticides, which were applied at a concentration of 125 ng/cm2. LC–MS/MS results showed, however, that 20% of applied thiabendazole and 4.4% of applied phosmet had penetrated into the apples followin...