超高效液相色谱-串联质谱法同时检测辣椒中吡唑醚菌酯和戊唑醇农药残留

目的 建立QuEChERS-超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)同时检测辣椒中吡唑醚菌酯和戊唑醇农药残留的分析方法。方法 辣椒样品经乙腈提取, N-丙基乙二胺(primary secondary amine, PSA)+石墨化炭黑(graphitized carbon black, GCB)分散吸附剂净化, 采用甲醇(A)和0.1%甲酸水溶液(B)作为流动相进行梯度洗脱, 质谱应用电喷雾正离子源(electrospray ionization, ESI+), 采用多离子监测 (multiple reaction monitoring, MRM)模式对吡唑醚菌酯和戊唑醇的定量离子和定性离子进行监测, 外标法定量。结果 通过优化仪器方法中的流动相体系、质谱调谐参数及前处理过程中的提取溶剂和净化剂, 利用UPLC-MS/MS在6 min内完成吡唑醚菌酯和戊唑醇的分离分析。2种农药在0.001~ 0.100 mg/L范围内呈现出良好的线性关系(r>0.999), 检出限为0.001 mg/kg, 方法定量限为0.0025 mg/kg。当添加水平为0.0025、0.0050、0.0100、0.1000 mg/kg时, 吡唑醚菌酯在辣椒中的平均回收率为72.9%~96.1%, 相对标准偏差为3.5%~8.0% (n=5); 戊唑醇在辣椒中的平均回收率为78.4%~88.5%, 相对标准偏差为2.5%~11.8% (n=5)。 结论 本研究建立的方法检测速度快、灵敏度高、准确度和精密度符合农药残留分析的要求, 适用于辣椒中吡唑醚菌酯和戊唑醇农药残留的同时检测。

Simultaneous determination of pyraclostrobin and tebuconazole residues in peppers by ultra performance liquid chromatography-tandem mass spectrometry

Objective To establish a method for simultaneous determination of pyraclostrobin and tebuconazole residues in peppers by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods Pepper samples were extracted with acetonitrile, cleaned up with primary secondary amine (PSA)+graphitized carbon black (GCB), and separated by mobile system of methanol and 0.1% formic acid with gradient elution, then monitored for the quantitative ions and qualitative ions of pyraclostrobin and tebuconazole with multiple reactions monitoring (MRM) mode using electrospray ionization, and quantified with external standard method. Results This method made it possible that the simultaneous separation analysis was completed within 6 minutes using UPLC-MS/MS by modifying the mobile phase system and mass tune parameters in the instrumental method, and extraction solvent and purifying agent in the sample preparation. In the range of 0.001-0.100 mg/L, the linearity of pyraclostrobin and tebuconazole turned out excellent (r>0.999), and the limits of detection were 0.001 mg/kg, and the limits of quantitation of were 0.0025 mg/kg. With the spike level of 0.0025, 0.0050, 0.0100, 0.1000 mg/kg, the average recoveries of pyraclostrobin in peppers ranged from 72.9% to 96.1% and the relative standard deviations ranged from 3.5% to 8.0% (n=5), the average recoveries of tebuconazole in peppers ranged from 78.4% to 88.5% with the RSDs ranged from 2.5% to 11.8% (n=5). Conclusion The accuracy and precision of the method were appropriate for the pesticide residue analysis with a quick detection speed and high sensitivity, which is suitable for the simultaneous determination of pyrazole and tebuconol pesticide residues in pepper.