基于QuEChERS-超高效液相色谱-串联质谱法检测依维菌素在杨梅上的残留

为评价依维菌素在杨梅上的残留风险，开发了依维菌素在杨梅上的残留分析方法，并结合田间试验对依维菌素在浙江、福建、江西和云南4地杨梅上的残留消解状况进行了研究。采用改进的QuEChERS方法，结合超高效液相色谱-串联质谱 (UPLC-MS/MS) 对伊维菌素在杨梅上的残留量进行分析。结果表明:在0.001~0.5 mg/L范围内，依维菌素的质量浓度与对应的峰面积间呈良好线性关系，相关系数 (r) 为0.999 9。在0.005~1 mg/kg添加水平下，依维菌素在杨梅中的平均回收率为80%~95%，相对标准偏差为9.9%，表明该分析方法的准确度和精密度均符合残留分析的要求。方法检出限 (LOD) 为0.15 ng，定量限 (LOQ) 为0.005 mg/kg。田间试验结果表明，依维菌素在杨梅上的平均初始残留量为0.21~0.88 mg/kg，半衰期为2.1~6.1 d，表明依维菌素属易降解农药，但由于其在杨梅上初始残留量相对较高，因此应对其潜在的残留风险予以关注。

Residue analysis of ivermectin on Myrica rubra based on QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry

In order to evaluate the residual risks of ivermectin in Myrica rubra(Lour.)S.et Zucc. (waxberry), a residue analysis method of ivermectin in waxberry was developed. And the residue dynamics was studied based on field trials conducted in Zhejiang Province, Fujian Province, Jiangxi Province and Yunnan Province. The modified QuEChERS method coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to detect the residues in samples. The results showed that a good linear relationship (r=0.999 9) was obtained for ivermectin within the concentration range from 0.005 to 1 mg/L. Meanwhile, the average recoveries were 80%-95% with the maximum RSD of 9.9% at the spiked concentration range from 0.005 to 1 mg/kg. The recovery results inferred the accuracy and precision were accorded with the request of residue analysis. The LOD and LOQ of this method were 0.15 ng and 0.005 mg/kg, respectively. The field trial result showed that the initial residue of ivermectin in waxberry was 0.21-0.88 mg/kg and the half-life was 2.1-6.1 d, which revealed that ivermectin was an easily degradable pesticide. However, attention should be paid to the potential residue risks for the relatively higher initial residue.