22%苄嘧磺隆·五氟磺草胺SC在水稻土壤及稻田水中的残留分析方法

Residue Analysis of Bensulfuron-methyl and Penoxsulam 22% SC in Rice Soil and Field Water

[目的]建立超高效液相色谱串联质谱法检测水稻土壤、稻田水中苄嘧磺隆、五氟磺草胺残留的方法。[方法]土壤中的苄嘧磺隆和五氟磺草胺用乙腈提取,采用Qu ECh ERS法净化,稻田水中的苄嘧磺隆和五氟磺草胺用乙酸乙酯萃取,用Agilent Zorbax RRHD Eclipse Plus C18色谱柱分离,以0.1%甲酸水-乙腈为流动相进行梯度洗脱,流速为0.3 m L/min,采用正离子电喷雾电离模式测定,外标法定量。[结果]方法的线性范围为0.002~1.0 mg/L,相关系数分别为0.9997和0.9999;在0.01、0.05、0.50 mg/L三个添加水平下,水稻土壤中,2种农药的平均回收率为77.1%~103.8%,相对标准偏差为2.4%~8.0%(n=5);在稻田水中平均回收率为77.6%~94.2%,相对标准偏差为2.4%~7.6%(n=5)。在上述检测条件下,苄嘧磺隆和五氟磺草胺的最小检出量分别为6.0×10-3、7.0×10-3ng。[结论]该方法的灵敏度、准确度、精密度符合农药残留分析的要求,适合大批量的水稻样品的检测。

[Aims] A new method was developed for residue analysis of bensulfuron-methyl and penoxsulam in rice soil and field water by ultra performance liquid chromatography-mass spectrum. [Methods] Bensulfuron-methyl and penoxsulam residues in soil were extracted with acetonitrile and purified by QuEChERS method. Bensulfuron-methyl and penoxsulam residues in field water were extracted with ethyl acetate. Then Agilent Zorbax RRHD Eclipse Plus C^s chromatographic column was used to separate the residues, the mixture of 0.1% formic acid aqueous solution and acetonitrile was used as mobile phase in gradient elution, and the flow rate was 0.3 mL/min. Finally, the samples were detected by UPLC-MS/MS under positive electrospray ionization and multiple reaction monitoring mode. The matrix-matched external standard calibration curves were used for the quantitative analysis. [Results] The linear range of calibration curves was 0.002-1.0 mg/L and linear correlation coefficients were 0.9997 and 0.9999. For rice soil, the average recoveries of the two pesticides were 77.1-103.8% at spiked levels of 0.01, 0.05 and 0.50 rag/L, with relative standard deviations were 2.4-8.0% （n=5）. The limits of quantitation were 0.0l mg/L. For field water, the average recoveries of the two pesticides was 77.6-94.2%, relative standard deviations were 2.4-7.6% （n=5）. Under these conditions, the limits of detection for bensulfuron-methyl and penoxsulam were 6.0 ×10^（-3） and 7.0 ×10^（-3） ng, respectively. [Conclusions] The method is simple and reliable, met with the requirement for pesticide residue analysis, which can be applied for determining bensulfuron-methyl and penoxsulam residues in rice samples.