氯氟氰虫酰胺在稻田环境中的残留及消解特性

Residue and dissipation of cyhalodiamide in rice paddy

建立了一种快速、灵敏、可靠的用于分析稻田环境中氯氟氰虫酰胺残留的方法,同时研究了氯氟氰虫酰胺在稻田环境中的消解特性。田间样品经液-液分配及优化的Qu ECh ERS方法提取及净化,采用超高效液相色谱-串联质谱法（UPLC-MS/MS）进行定性、定量分析。结果表明：添加水平分别在0.002-0.5 mg/kg下,氯氟氰虫酰胺在稻田水、土壤以及水稻植株空白样品中的平均添加回收率为70%-101%,相对标准偏差（RSD,n=5）为0.7%-9.1%,其在田水、土壤和水稻植株中的最低检测浓度分别为0.002、0.005和0.01 mg/kg。该方法可满足水稻及其环境中氯氟氰虫酰胺残留量的检测要求。消解动态试验结果表明,氯氟氰虫酰胺在稻田水、土壤及水稻植株中的消解过程符合一级动力学方程,消解半衰期分别为4.8-7.7 d、5.2-8.3 d和1.5-15.4 d,属于易消解农药。

In the present work,a rapid,sensitive and efficient analytical method was developed for the determination of cyhalodiamide in rice paddy samples including paddy water,soil and rice straw,and accordingly the residue and dissipation of cyhalodiamide in the rice paddy were also investigated.Residues of cyhalodiamide were extracted and purified via a modified Qu ECh ERS（ quick,easy,cheap,effective,rugged and safe） method and liquid-liquid extraction（ LLE） and detected by ultra performance liquid chromatography-tandem mass spectrometry（ UPLC-MS / MS） using electrospray ionization in positive mode. Average recoveries for residues of cyhalodiamide in paddy water,soil and rice strawwere acquired as 70%- 101%,with the relative standard deviation（ RSD） from 0. 7% to9. 1% and the minimum detectable concentration of 0. 002,0. 005 and 0. 01 mg / kg,respectively,which illustrates the favorable applicability of this optimized method and indicates that the accuracy can meet the demand for the sensitive detection of cyhalodiamide in the rice paddy. Through the field trial,kinetics of residual cyhalodiamide in paddy water,soil and rice plant were found to be in accordancewith the first-order rate equation with the half-lives of 4. 8- 7. 7 d,5. 2- 8. 3 d and 1. 5- 15. 4 d,respectively,which suggests that cyhalodiamide is an easily degradable compound in the environment.