牛奶中双甲脒残留量气质联用测定方法研究

Detection of amitraz pesticide residues in milk using GC-MS

研究了牛奶中双甲脒的气相色谱-质谱检测方法。实验结果表明:在酸性条件下,牛奶试样中的双甲脒水解生成2,4-二甲基苯胺,得到的产物加入碱性溶液Na OH(4 mol·L^(-1))后用适量正己烷萃取,过滤后供气相色谱质谱测定。在10~150μg·L^(-1)浓度范围内,2,4-二甲基苯胺的浓度与其测得的峰面积有较好的线性关系,线性方程Y=39942Χ(μg·L^(-1))-223586,r=0.9988,检出限为3.0 ng·m L^(-1)。在空白牛奶样品中,添加双甲脒标准溶液,做加标回收实验,结果表明平均回收率为104.1%~106.8%,相对标准偏差(RSD)为1.77%和3.08%。实验证明该方法快速,分离度较好,适用于牛奶中双甲脒含量的检测。

This paper studied amitraz＇s residues in milk by gas chromatography-mass spectrometry method. Under acidic conditions, the amitraz of milk sample hydrolyzes 2,4-dimethyl aniline, the obtained product was added sodium hydroxide solution （4 mol·L^-1） and added an appropriate amount of n-hexane extraction, then use gas chromatography mass spectrometry to determine. In 10-150μg·L^-1 concentration range, the concentration of 2,4-dimethyl aniline and measured peak area has a good linear relationship, relationship equation Y=39942X（Mg·L^-1）-223586, r=0.9988, the detection limit was 3.0ng·mL^-1. Blank milk samples added 2,4-dimethyl aniline standard solution, do spiked recovery experiments, the results show that the average recovery rate was 104.1% and 106.8 %,relative standard deviation （RSD） was 1.77% and 3.08%. The method is rapid, has a good separating degree for detecting milk amitraz content.