Dissipation Profiles of Tristyrylphenol Ethoxylate Homologues in Lettuce under Greenhouse and Field Conditions.

Tristyrylphenol ethoxylates (TSPEOs) have been increasingly used in pesticide formulations as inert ingredients in China, but little information exists on the dissipation behavior of TSPEOs in foodstuffs. In this work, a rapid method for measuring TSPEO homologs in lettuce using QuEChERS and HPLC-MS/MS was established. This method was used to study the dissipation and distribution profiles of TSPEOs in lettuce. TSPEO homologs degraded rapidly under greenhouse and field conditions, with half-lives of 2.18-5.39 and 1.82-5.52 days, respectively. TSPEOn (n = 6-9) were relatively persistent in the field. The distribution profiles showed an obvious difference between the two conditions. TSPEOn (n = 14-18) degraded to shorter-chain TSPEOs with time, and a two-peak (TSP16EO and TSP10EO) homolog distribution profile occurred between 7 and 14 days of treatment under greenhouse conditions. This work improves the understanding of the dissipation behavior of TSPEO homologs in lettuce.