草莓中氯吡脲的残留动态研究及安全性评价

A Study on Residual Dynamics of Forchlorfenuron in Strawberry and Safety Evaluation

为研究利用超高效液相色谱-串联质谱（UHPLC-MS/MS）快速准确测定草莓中氯吡脲残留的方法,以及氯吡脲在草莓中的消解动态、最终残留情况并进行安全性评价。采用正离子多反应监测模式,外标法定量。氯吡脲在0.2~5μg/L线性关系良好,检出限为0.1μg/kg,定量限为0.3μg/kg,在不同添加水平下,氯吡脲的平均回收率范围为88.3%~96.6%,相对标准偏差范围为3.6%~6.9%。田间试验结果表明氯吡脲在草莓中的消解半衰期为4.6 d,属易降解性农药。最终残留试验结果表明,在草莓采收时均有微量氯吡脲检出,建议草莓的采收安全间隔期至少为7 d。

A fast and accurate method for the determination of forchlorfenuron in strawberry using ultrahigh performace liquid chromatograph-tandem mass spectrometry（ UHPLC-MS / MS） was worked out,and the degradation of forchlorfenuron in strawberry was investigated and a safety assessment was conducted. The forchlorfenuron residue was analyzed by ion multiple reaction monitoring（ MRM） negative mode and the external standard method was used for quantitative analysis.The results showed that a good linearity was in the range of0.2-5 μg / L,and the limit of detection of forchlorfenuron was 0.1 μg / kg,and the limit of quantitaty was 0.3 μg / kg.The average recovery of forchlorfenuron at different spiked levels was in the range of 88.3% to 96.6%,and the relative standard deviations were in the range of 3.6% to 6.9%. The field experiment indicated that there was trace forchlorfenuron residues in strawberry. The half life of for chlorfenuron in strawberry was 4. 6 days. This suggested that forchlorfenuron is a kind of readily degradable pesticide.The trace forchlorfenuron was detected in the harvest time of strawberry by the final residue test,and it is suggested that the safe interval of the strawberry harvest should not be less than 7 d.