Dissipation of Chlorpyrifos in Bottled Tea Beverages and the Effects of (−)-Epigallocatechin-3-Gallate

Abstract

Bottled tea beverages (BTB) are popular for the health benefits and convenience. Because chlorpyrifos (CP) is commonly used as a biomarker for exposure, as well as a pesticide in the field, it is important to determine the dynamics of CP dissipation in BTB to better perform risk assessments. This study focused on the dynamic behavior of CP for 22 days by fortifying bottled green tea, dark tea, and oolong tea beverages with the parent chemical and analyzing the degradation products. Photoinduction was used to generate the two transient intermediates: the reactive oxygen species from H2O2 and the triplet excited state of CP from the parent chemical in water were designed to observe the effects of (-)-epigallocatechin-3-gallate (EGCG) on the dissipation and transformation of CP. The results indicated that the CP degraded in BTB and the main products were detected. The half-life values of CP illustrated that EGCG increased the dissipation of CP by combination with CP and inhibited the generation of CP-oxon by scavenging the emerged oxidant, the reactive oxygen species, and interfering with the transformation of the triplet excited state of CP. This work suggests EGCG could play various roles in the dissipation and transformation of CP. Thus, a comprehensive identification of CP degradation should be performed when assessing the exposure risk in drinking BTB.