噻苯隆在芒果中的残留与消解动态研究

Study on the residue and digestion dynamics of thidiazuron in Mangifera indica

目的 建立超高效液相色谱-串联质谱法检测芒果中噻苯隆的方法,探究噻苯隆在芒果中的残留和消解动态规律,评价噻苯隆在芒果上使用的安全性。方法 本实验的施药浓度、次数、施药间隔,按照NY/T788—2018《农作物中农药残留实验准则》结合芒果生产实际进行适当调整,于2021年在广西大学校内芒果基地开展噻苯隆在芒果中的残留和消解动态实验。结果 在0.4~40.0μg/kg添加水平范围内,噻苯隆在芒果中的平均添加回收率为86.80%~89.77%,相对标准偏差为1.48%~3.70%,方法 检出限为0.12μg/kg,定量限为0.40μg/kg。噻苯隆在芒果中的消解动态曲线符合一级动力学方程,半衰期为3.57~3.89d,属于易降解农药。最终残留实验结果 表明,在芒果谢花后25、35、45d各喷施1次噻苯隆,共喷3次,在距离最后一次施药45d后,临近生理成熟期的芒果中噻苯隆含量均低于定量限。结论 在芒果谢花后25、35、45 d各喷施1次噻苯隆,共喷3次,噻苯隆在芒果中的残留量小于我国蔬菜瓜果中噻苯隆的最大残留限定值。

Objective To establish a method for the determination of thidiazuron in Mangifera indica by ultra performance liquid chromatography-tandem mass spectrometry,explore the residue and digestion dynamics of thidiazuron in Mangifera indica,and evaluate the safety of thidiazuron in Mangifera indica.Methods The application concentration,times and interval of this experiment were properly adjusted according to the NY/T 788—2018 Guideline for the testing of pesticide residues in crops and the actual production of Mangifera indica.The residue and digestion dynamics experiments of thidiazuron in Mangifera indica were carried out in Mangifera indica base of Guangxi University in 2021.Results In the range of 0.4-40.0 μg/kg,the average recoveries of thidiazuron in Mangifera indica was 86.80%-89.77%,the relative standard deviations were 1.48%-3.70%,the limit of detection of thidiazuron was 0.12 μg/kg,while the limit of quantification was 0.40 μg/kg.The digestion of thidiazuron in Mangifera indica was consistent with the first-order kinetic equation.The half-life of thidiazuron in Mangifera indica was 3.57-3.89 d,it belonged to easily degradable pesticide.The final residue experiment results showed that thidiazuron was sprayed once at 25,35 and 45 d after Mangifera indica flowering,and a total of 3 times,and the content of thidiazuron in Mangifera indica were all below that limit of quantitation at the near physiological maturity 45 d after the last application.Conclusion Thidiazuron is sprayed once at 25,35 and 45 d after Mangifera indica flowering,and a total of 3 times,and the residue of thidiazuron in Mangifera indica is less than the maximum residue limit of vegetables and fruits set by the country.