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建立了分散固相萃取-分散液液微萃取与气相色谱/质谱联用测定玉米和大米中痕量氟虫腈及其代谢物残留的分析方法。使用乙腈和水混合溶液作为萃取溶剂,盐析后,提取液经N-丙基-乙二胺硅烷固相萃取材料(PSA)作为吸附剂后,采用分散液液微萃取步骤将目标物从到微量四氯乙烯中。对影响分散液液微萃取效率的因素,包括萃取溶剂种类及体积、盐等条件进行了优化。在0.02~1μg/m L浓度范围内,线性关系良好(r≥0.9987)。在玉米和大米样品中氟虫腈添加浓度为1.0~25.0μg/g时,平均回收率在70.4%~95.1%之间,相对标准偏差(n=5)在2.6%~12%之间,以最低添加浓度1μg/kg作为定量限。
A method for the determination of trace fipronil and its metabolites in corn and rice by dispersive solid phase extraction-liquid-liquid microextraction and gas chromatography / mass spectrometry was established. The mixture was extracted with acetonitrile and water as the extraction solvent. After the salting-out, the extract was purified by Nano-SBA-PSA as the adsorbent and then dispersed liquid-liquid microextraction from Trace tetrachlorethylene. Factors influencing the efficiency of dispersive liquid-liquid microextraction, including the types of solvent extraction, volume and salt, were optimized. In the range of 0.02 ~ 1μg / m L, the linearity was good (r≥0.9987). The average recoveries ranged from 70.4% to 95.1% and the relative standard deviations (n = 5) ranged from 2.6% to 12% for fipronil at 1.0-25.0 μg / g in corn and rice samples The lowest concentration of 1μg / kg as the limit of quantification.