Pesticides residues in food may pose harmful effects on human health. Previous studies demonstrated the effective removal of surface pesticides using baking soda (NaHCO3). However, the studies focused on pure pesticide active ingredients (AIs). As pesticides are often applied with adjuvants, such as non-ionic surfactants, to facilitate the stability and functionality of the AIs in agricultural practice, the objective of this study is to investigate whether the non-ionic surfactant (Alligare 90) affects the persistence of the pesticides on the fresh produce surfaces during washing. Wettability and evaporation rate of two pesticides (Thiabendazole and Phosmet) mixed with Alligare 90 were determined respectively in order to correct the unit concentration applied on produce surfaces. Surface-enhanced Raman spectroscopy (SERS) with gold nanoparticle (AuNP) mirror substrate was applied to analyze the pesticide formulations before and after washing with 1% NaHCO3. Compared to pure pesticide AIs, Alligare 90 enhanced the SERS signal of Thiabendazole whereas decreased the corresponding Intensity of Phosmet on both spinach and apple surfaces. However, our results indicate that this non-ionic surfactant did not affect the removal efficacy of pesticides using 1% NaHCO3. This study demonstrated the potential efficacy of the baking soda washing strategy to remove surface pesticides applied with non-ionic surfactants. Future studies will involve testing and comparing various adjuvants.

Investigate the impact of a non-ionic surfactant on pesticide persistence on fresh produce surface during baking soda washing using surface enhanced Raman spectroscopy

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.