QuEChERS-GC/MS法测定草莓中的嘧菌环胺

QuEChERS-GC/MS Method for Determination of Cyprodinil in Strawberry

为建立一种QuEChERS预处理样品,气相色谱质谱联用技术测定草莓中嘧菌环胺的分析方法,采用乙腈提取草莓中的嘧菌环胺,提取液经无水硫酸镁、无水醋酸钠、N-丙基乙二胺(PSA)和十八烷基键合硅胶(C18)盐析、净化后,在气相色谱-质谱(GC-MS)上以DB-5ms毛细管柱进行分离测定。以保留时间和离子对定性,基质内标法定量。结果表明,嘧菌环胺在0.05~5μg/m L质量浓度范围线性关系良好,相关系数r为0.998 9。检出限为0.006 mg/kg,定量限为0.012 mg/kg。加标浓度在0.2~2 mg/kg时的平均回收率均在86.5%~93.8%之间;精密度测试中6次测定结果的相对标准偏差在2.32%~3.68%之间,重复性检测6次进样相对标准偏差为2.2%。该方法前处理简单、快速、节省溶剂,可适用于草莓中嘧菌环胺含量的监测。

A method was developed to determine residue of cyprodinil in strawberry by QuEChERS GC/MS method. Acetonitrile was selected to extract cyprodinil of strawberry, and anhydrous magnesium sulfate and anhydrous magnesium sodium acetate were used for salting out. PSA and C18 were selected as cleaning agent. Purified solution was separated in DB-5 ms column and analyzed by GC-MS. Retention time and fragment ion pair were used as qualitative determination, and matrix internal standard was used as quantitative deternation. The result showed that the concentration of cyprodinil pesticide had good linear relationship in the range of 0.05 μg/mL to 5 μg/mL, and correlation coefficient(r) was 0.998 9. The detection limit of cyprodinil was 0.006 mg/kg, and quantification limit was 0.012 mg/kg. The average recoveries at 0.2-2 mg/kg were ranged from 86.5% to 93.8%. Relative standard deviation(RSD) of precision was 2.32%-3.68%(n=6), and RSD of reproducibility was 2.2%(n=6). This method was easy for pre-treatment, efficient and solvent saving, which could be used to determine cyprodinil residues in strawberry.