甲醇衍生法测定环境水体中八种酸性除草剂

文章建立了一种测定环境水体中8种酸性除草剂残留量的分析方法。1 000 mL样品在pH<2的情况下由乙醚分三次萃取后,萃取液经脱水,K-D浓缩至约1 mL,转移到衍生瓶中。在衍生瓶中补加2 mL正己烷、1 mL甲醇、8滴浓硫酸,80℃水浴加热1 h,进行甲醇衍生化处理,衍生后的样品运用气相色谱-质谱联用-分段选择离子扫描技术测定,内标法定量。结果表明:8种除草剂在0.05～2.5μg/L范围内线性均良好;方法灵敏度高,检出限均低于或等于0.02μg/L;方法的准确度和精密度高,在0.10、0.50、1.00、1.50μg/L添加水平下所有除草剂的回收率均在82.07%～116.99%之间,相对标准偏差RSD≤7.68%;经实际样品检测,可用于测定环境水体中酸性类除草剂的残留量。

Determination of 8 Kinds of Acid Herbicide Residues in Water by Methanol-derived Method

Gas chromatography-mass spectrometric(GC-MS) method was proposed for analyzing 8 kinds of acid herbicide residues in water.Herbicide residues which were extracted from water with ether,then derived by methanol and analyzed by GC-MS-SIM were quantified by internal standard method.Results indicated that linear of all herbicides is good in the range of 0.05 to 2.5 μg/L,with the detection limit under or equal to 0.02 μg/L.The results were accurate and stable,with the recoveries of all herbicides between 82.07%～116.99% at 0.10,0.50,1.00,1.50 μg/L,and relative standard deviations below 7.68%.The method which is reliable and stable can be used in determination of herbicides residues in water.