固相萃取-气相色谱-串联质谱法同时测定红茶中113种农药残留

Determination of 113 pesticide residues in red tea by gas chromatography-tandem mass spectrometry combined with solid phase extraction

中文关键词:  固相萃取  气相色谱-串联质谱法  红茶  农药残留

英文关键词:solid phase extraction  gas chromatography-tandem mass spectrometry  red tea  pesticide residues

中文摘要:

      目的 建立一种固相萃取净化(solid phase extraction, SPE)-气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS/MS)测定红茶中113种农药多残留的分析方法。方法 样品采用1%(V:V)醋酸乙腈水溶液(2:1, V:V), 加入6 g MgSO4, 1.5 g乙酸钠进行提取。考虑到农药化合物结构的差异性影响, 本文采用2种不同的净化方法, 方法Ⅰ是采用Cleanert TPT柱对95种农药进行净化, 方法Ⅱ采用PSA柱与50 mg石墨化碳黑(graphitized carbon black, GCB)对18种平面或类平面结构的农药进行净化, 然后用GC-MS/MS进行分析, 基质匹配标准溶液内标法定量。结果 结果表明, 113种农药在5~200 ng/mL范围内线性关系良好, 相关系数均大于0.993, 方法的添加回收率为50%~134.2%, 相对标准偏差(relative standard deviations, RSD)为0.1%~13.7%, 定量限(limits of the quantitation, LOQ)为10~50 μg/kg。结论 该方法灵敏度、准确度和精密度均能满足红茶中农药多残留的分析要求。

英文摘要:

      Objective To establish a method for the determination of 113 kinds of pesticide residues in tea by solid phase extraction purification (SPE)-gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods The samples were extracted with 1% (V:V) acetic acid-acetonitrile water solution (2:1, V:V) and 6 g MgSO4 and 1.5 g sodium acetate. As the influences of the compound structures, the extracts were purified by two methods. In purified method Ⅰ, 95 pesticide residues were used by the SPE of Cleanert TPT, while the other 18 planar structure compounds or the compounds with some planar groups were used by the SPE of PSA and 50 mg GCB. After filtration, the target compounds were detected by GC-MS/MS and quantified with internal standard method by the matrix match standard solutions. Results The results showed that 113 pesticides had good linear relationships in the range of 5-200 ng/mL, with the correlation coefficients were all better than 0.993. The average recoveries of the 113 pesticide residues ranged from 50%-134.2%, with the relative standard deviations of 0.1%-13.7%. The limits of the quantitation were 10-50 μg/kg. Conclusion The sensitivity, accuracy and precision of the method can meet the analysis requirements of pesticide residues in black tea.