Quantifying the effect of non‐ionic surfactant alkylphenol ethoxylates on the persistence of thiabendazole on fresh produce surface

Abstract BACKGROUND Understanding the role of adjuvants in pesticide persistence is crucial to develop effective pesticide formulations and manage pesticide residues in fresh produce. This study investigated the impact of a commercial non‐ionic surfactant product containing alkylphenol ethoxylates (APEOs) on the persistence of thiabendazole on apple and spinach surfaces against the 30 kg m −3 baking soda (sodium bicarbonate, NaHCO 3 ) soaking, which was used to remove the active ingredient (AI) in the cuticular wax layer of fresh produce through alkaline hydrolysis. Surface‐enhanced Raman scattering (SERS) mapping method was used to quantify the residue levels on fresh produce surfaces at different experimental scenarios. Four standard curves were established to quantify surface thiabendazole in the absence and presence of APEOs, on apple and spinach leaf surfaces, respectively. RESULTS Overall, the result showed that APEOs enhanced the persistence of thiabendazole over time. After 3 days of exposure, APEOs increased thiabendazole surface residue against NaHCO 3 hydrolysis on apple and spinach surfaces by 5.39% and 10.47%, respectively. CONCLUSION The study suggests that APEOs led to more pesticide residues on fresh produce and greater difficulty in washing them off from the surfaces using baking soda, posing food safety concerns. © 2023 Society of Chemical Industry.