| With the deepening of research on the toxicity of pesticide adjuvant in recent years,its safety has also received increasing attention.Tristyrylphenol ethoxylates(TSPnEOs)are one of the nonionic surfactant,widely used in domestic pesticide formulations and its usage amount is inferior to alkylphenol ethoxylates.Toxicity studies have shown that TSPnEOs are teratogenic,subchronic and their intermediates produced during production and degradation can induce estrogenic activity.With the widespread application of pesticide formulations,TSPnEOs are transported to the agricultural environment which not only affect the quality and safety of agro-products but also threatens the agro-ecological environment.Therefore researches on TSPnEOs residue detection methods,degradation rules and health risk assessment in agro-products is of great significance for the scientific evaluation and management of TSPnEOs pesticide adjuvant in China,and is meaningful to protect consumers' health and environmental safety.In this study,a GPC-LC-MS/MS analytical method of TSPnEO(n=6-29)with different degrees of polymerization in agro-products was established.The residual concentration of TSPnEO(n=6-29)in fruit samples were investigated.The correlation between the residual concentration of TSPnEO(n=6-29)and the pesticide residue concentration in fruit samples was analyzed.Health risks of ?TSPnEO(n=6-29)to human body were evaluated and the residual characteristics and degradation rules of TSPnEO(n=6-29)in agro-products were explored.(1)Gel permeation chromatography(GPC)and liquid chromatography-tandem mass spectrometry(LC-MS/MS)residue analysis method was established for 24 TSPnEO(n=6-29)and different polymerization degrees were separated in 11.25 min.The average recoveries of this method are 73%-143%,the relative standard deviations are 3%-19%,limits of quantification are 0.001-0.235 ?g/kg.This method has been successfully applied to the analysis of agro-products such as cherry,peach and kiwifruit.(2)The residual concentration and characteristic distribution of TSPnEO(n=6-29)with different polymerization degree in 361 cherry,peach and kiwifruit samples from the main producing areas in China were investigated and analyzed in 2016 and 2017.TSPnEO(n=6-29)was detected in all samples and the total concentration of ?TSPnEO(n=6-29)was 0.5-14786.0 ?g/kg(median 85.0 ?g/kg).The residual concentration of TSPnEO(n=6-29)in kiwifruit was significantly higher than that in cherries and peaches;the concentration of samples in 2017 was generally higher than that in 2016.Correlation analysis showed that there was a significant correlation between the total concentration of TSPnEO(n=6-29)and the residual concentration of acetamiprid(r=0.119,p<0.05)and carbendazim(r?-0.170,p<0.01).It is indicated that the residue of TSPnEO(n=6-29)may be related to the use of these pesticides.A dietary risk assessment based on monitoring data of three fruits indicated that the dietary intake risks(short/acute risk,long-term/chronic risk)of ?TSPnEO(n=6-29)were acceptable.(3)Through the residue test of TSPnEOs on cucumber it was found that the half-lives of different polymerization degrees of TSPnEO(n=6-29)in cucumber and soil were 3.5-7.7 d and 4.3-6.9 d respectively.The closer the polymerization degree is to the average polymerization degree(n=16)the higher the detection concentration is the faster the digestion rate is;the TSPnEOs usage times the dosage and the recovery interval are the main influencing factors.Through the residue experiment of TSPnEOs on cucumber,it was found that the half-lives of TSPnEO(n=6-29)with different polymerization degrees in cucumber and soil were 3.5-7.7 d and 4.3-6.9 d,respectively.The closer the polymerization degree is to the average polymerization degree(n=16),the higher the detection concentration and the faster the degradation rate are.The usage number and dosage of TSPnEOs and harvest interval were the main influencing factors. |
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