Pesticide Residues and Environmental Pollution Department, Central Agricultural Pesticide Laboratory, Agricultural Research Center, Giza, Egypt.
Biomed Chromatogr. 2020 Jul;34(7):e4836. doi: 10.1002/bmc.4836. Epub 2020 May 3.
The dissipation dynamic and residues of spiroxamine in open-field-grown strawberries were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spiroxamine application was performed according to Egyptian good agricultural practices recommendation. A QuEChERS-based extraction method along with direct analysis with an LC-MS/MS analytical method were optimized and validated, and the specificity of the techniques used was considered satisfactory. Good linearity (R > 0.999) was obtained for spiroxamine within the range of 0.001-0.1 μg/ml. The mean recoveries varied between 97.1 and 108.2%, with inter- and intra-day precision (RSD) <4.9%. The limit of quantitation for spiroxamine was 0.001 mg/kg. The results indicated that spiroxamine degradation in strawberry followed first-order kinetics (R > 0.9929) with an estimated half-life value of 4.71 days. Considering the Australian maximum residue limit (0.05 mg/kg) in strawberry and based on the results from residue trials with a preharvest interval of 14 days for strawberry, compliance can be expected. The present results could provide guidance to fully evaluate the risks of spiroxamine residues, preventing any potential health risk to consumers.
采用液相色谱串联质谱法（LC-MS/MS）测定了田间生长草莓中螺螨酯的消解动态和残留。螺螨酯的应用按照埃及良好农业规范推荐进行。优化并验证了基于 QuEChERS 的提取方法和直接 LC-MS/MS 分析方法，所使用技术的特异性令人满意。螺螨酯在 0.001-0.1μg/ml 范围内具有良好的线性（R>0.999）。螺螨酯的平均回收率在 97.1%至 108.2%之间，日内和日间精密度（RSD）<4.9%。螺螨酯的定量限为 0.001mg/kg。结果表明，草莓中螺螨酯的降解符合一级动力学（R>0.9929），半衰期估计值为 4.71 天。考虑到澳大利亚在草莓中的最大残留限量（0.05mg/kg），并且基于草莓 14 天的休药期残留试验结果，可以预期符合要求。本研究结果可为全面评估螺螨酯残留风险提供参考，防止对消费者造成任何潜在的健康风险。
