超高效液相色谱-串联质谱法测定粮食中克螨特残留量

Determination of propargite residues in grains by ultra performance liquid chromatography-tandem mass spectrometry

为了建立粮谷中克螨特残留量的测定方法,采用了固相萃取-超高效液相色谱-串联质谱法进行检测。样品加入适量水浸润后,乙腈超声提取,液液萃取后,经碳十八和氨基固相萃取柱净化,超高效液相色谱串联质谱多反应监测测定,外标法定量。结果显示,克螨特在0.001～0.020 mg/L时,检测方法线性良好,相关系数为0.999 8,检测限为0.2μg/kg,定量限为1.0μg/kg。对小麦、大麦、燕麦、大米、黑米、玉米6种粮谷进行3个水平的添加回收试验(1μg/kg、2μg/kg、5μg/kg),结果回收率在60.5%与90.2%之间,相对标准偏差为1.7%～13.7%。运用该方法检测粮谷时基本没有干扰现象,适用于粮谷中克螨特残留的测定。

The techniques of solid-phase extraction and ultra performance liquid chromatography-tandem mass spec- trometry were used to develop a method for determination of propargite residues in grains. The samples were dipped into wa- ter for 30 min, extracted using acetonitrile by ultrasonic method, and then purified by C18 and NH2 solid-phase extraction column. The target compound was separated on a C18 column with a gradient elution of 0.1% formic acid aqueous solution （including 5 mmol/L ammonium acetate） and acetonitrile （including 0.1% formic acid） as mobile phase. The identifica- tion and quantification were conducted using electrospray ionization in positive ion mode （ ESI＋ ） with multiple reactions mo- nitoring （MRM）, and were confirmed by external standard method. The linearity of method was good between 1.0 μg/L and 20.0 μg/L propargite （r2 =0. 999 8）. The limit of detection （LOD） was 0.2 p.g/kg, and the limit of quantification （LOQ） was 1.0 μg/kg. The recoveries were in the range of 60.5%-90.2% at three spiked levels （1 μg/kg, 2 μg/kg and 5 μg/kg） in six grains （wheat, barley, oat, rice, black rice and corn） , and the relative standard deviations （RSD） were in the range of 1.7% -13.7%. The method works well with no interference, and is suitable for the quantitative deter- mination of propargite residues in grains.