多重吸附同步净化-气相色谱-质谱法测定干性样品中丁烯氟虫腈的残留量

建立了干性样品中丁烯氟虫腈残留量的多重吸附同步净化(MASP)-气相色谱-质谱检测方法。前处理以1%乙酸-乙腈提取样品,应用MASP法对样品同时进行提取、盐析和净化,并利用气相色谱-质谱仪在选择离子扫描(SIM)模式下进行检测,以基质匹配标准溶液外标法定量。结果表明:丁烯氟虫腈在2~100 μg/L范围内线性关系良好,相关系数(r²)不小于0.999;在2~10 μg/kg添加水平范围内,丁烯氟虫腈的平均回收率为92.2%~97.5%,相对标准偏差(RSD, n=6)为2.69%~5.21%;方法检出限(S/N=3)为2 μg/kg;定量限(S/N=10)为6 μg/kg。本方法操作简便、快速、准确,可用于干性样品中丁烯氟虫腈的日常检测。同时,对丁烯氟虫腈的裂解机理进行了探讨。

Determination of butene-fipronil residue in dry samples by multiple adsorption synchronous purification-gas chromatography-mass spectrometry

A method was developed for the determination of butene-fipronil residue in dry samples by multiple adsorption synchronous purification (MASP)-gas chromatography (GC)-mass spectrometry (MS). After extracted with 1% acetic acid-acetonitrile, the samples were pretreated with MASP method including extraction, salting-out and purification procedures, and analyzed with GC-MS under the selected ion monitoring (SIM) mode, and then quantified by matrix-match standard solution with external standard method. The results showed good linearity in the range of 2-100 μg/L with the correlation coefficients (r²)not less than 0.999. The average fortified recovery of butene-fipronil in samples was found in the range of 92.2%-97.5% at three fortified levels from 2 to 10 μg/kg, with the relative standard deviations of 2.69%-5.21% (n=6). The limit of detection (S/N=3) for butane-fipronil was 2 μg/kg and the limit of quantification (S/N=10) was 6 μg/kg. The method is simple, rapid and accurate, and could be used for the routine analysis of butane-fipronil in dry samples. Meanwhile, the pyrolysis mechanism of butane-fipronil, as a new substance, is discussed.