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目的建立水果中氟虫腈残留的气相色谱-电子捕获检测法(GC-ECD)和气相色谱-质谱(GC-MS)分析方法。方法试样经乙腈提取,以正己烷液液分配和N-丙基乙二胺(PSA)固相萃取净化后,上机测定。结果 2种方法在5μg/L~100μg/L时,线性关系良好,相关系数(r)分别为0.999 2、0.999 9,检出限均为0.20μg/kg。在10μg/L、50μg/L、100μg/L 3种加标浓度下,GC-ECD法、GC-MS-NCI法的平均回收率分别为88.32%~96.53%、84.89%~98.13%,相对标准偏差(RSD)分别为3.00%~9.07%、3.17%~8.96%。运用所建立的GC-ECD法对实际样品进行了检测,90份水果样品中检出1份苹果阳性样品,并采用GC-MS-NCI法进行了确证,证明2种方法的检测结果一致。GC-ECD测得的含量为1.21μg/kg,GC-MS-NCI测得的含量为1.18μg/kg。结论 GC-ECD法与GC-MS-NCI法的灵敏度、精密度和LOD均符合残留分析要求,具有简单、快速、可靠、灵敏度高的特点,适合于水果中氟虫腈残留的痕量分析。
Objective To establish a gas chromatography-electron capture detection (GC-ECD) and gas chromatography-mass spectrometry (GC-MS) analysis method for fipronil residues in fruits. Methods The samples were extracted with acetonitrile and purified by n-hexane liquid-liquid extraction and N-propyl ethylenediamine (PSA) solid-phase extraction. Results The linearity of the two methods was good at 5μg / L ~ 100μg / L with the correlation coefficients (r) of 0.999 and 2.09999, respectively. The detection limits were both 0.20μg / kg. The average recoveries of GC-ECD method and GC-MS-NCI method were 88.32% -96.53% and 84.89% -98.13% at the concentration of 10μg / L, 50μg / L and 100μg / Deviations (RSD) were 3.00% ~ 9.07%, 3.17% ~ 8.96%. The established GC-ECD method was used to test the real samples. One apple positive sample was detected from 90 fruit samples and confirmed by GC-MS-NCI method. The results of two methods were consistent. The content measured by GC-ECD was 1.21 μg / kg and the content measured by GC-MS-NCI was 1.18 μg / kg. Conclusion The sensitivity, precision and LOD of GC-ECD method and GC-MS-NCI method are in line with the requirements of residue analysis. They are simple, rapid, reliable and sensitive. They are suitable for the trace analysis of fipronil residues in fruits.