异菌脲、咪鲜胺及其代谢物在哈密瓜贮藏保鲜中的降解动态及安全评价

Degradation dynamics and risk assessment of dietary exposure to iprodione,prochloraz and its metabolites during fresh-keeping storage of Hami cantaloupe

目的评价哈密瓜贮藏过程中异菌脲、咪鲜胺及其代谢物2,4,6-三氯苯酚的残留消解动态,评估其人体慢性膳食摄入风险。方法采用气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测哈密瓜在冷藏和常温贮藏条件下异菌脲、咪鲜胺和2,4,6-三氯苯酚随贮藏期延长残留量的变化,并对膳食摄入风险进行评估。结果异菌脲、咪鲜胺在哈密瓜中的消解动态均满足一级反应动力学方程,异菌脲在常温和冷藏条件下半衰期分别为3.3、3.6 d;咪鲜胺在常温和冷藏条件下半衰期分别为3.8、4.5 d。咪鲜胺的代谢物2,4,6-三氯苯酚在贮藏期间含量呈现增加趋势。一般人群对哈密瓜中实验农药的慢性膳食摄入的风险都较低,为可接受水平。结论本研究通过对哈密瓜中异菌脲、咪鲜胺及其代谢物贮藏保鲜过程中降解动态的研究,为合理规范使用杀菌剂提供了科学依据。

Objective To evaluate the residual dissipation dynamics and human dietary intake risk of iprodione,prochloraz and 2,4,6-trichlorophenol in Hami cantaloupe during storage.Methods A gas chromatography-tandem mass spectrometry(GC-MS/MS)method was established for the simultaneous determination of the residues of iprodione,prochloraz and 2,4,6-trichlorophenol in Hami cantaloupe during cold storage and normal temperature storage,the risk of dietary intake was evaluated.Results The iprodione and prochloraz in Hami cantaloupe all satisfied the first-order reaction kinetics equation.The half-lives of iprodione was 3.3 d at room temperature and 3.6 d at cold storage;the half-life of prochloraz was 3.8 d at room temperature and 4.5 d at cold storage.The content of 2,4,6-trichlorophenol,a metabolite of prochloraz,increased during storage.The risk of chronic dietary intake of experimental pesticides in cantaloupe in the general population was low and acceptable.Conclusions In this study,the degradation dynamics of iprodione,prochloraz and its metabolite in Hami cantaloupe during storage are studied to provide scientific basis for rational use of fungicides.