高效液相色谱法测定水中7种苯氧羧酸类除草剂

Determination of 7 phenoxyacid herbicides in waterby high performance liquid chromatography

采用液液萃取-固相萃取净化前处理方式,使用C8液相色谱柱,以甲醇/磷酸溶液作为流动相,进样40μL,使用紫外检测器在230 nm波长下,采用梯度洗脱方式进行分离,使7种苯氧羧酸类除草剂完全分离,外标法定量。当取样量为250 mL,定容体积为1mL时,检出限为0.04μg/L,测定下限为0.16μg/L。实验测得的7种除草剂的相关系数范围为0.999 6~0.999 8,对地下水、地表水、生活污水进行加标测试,测得相对标准偏差范围为1.9%~8.7%,加标回收率范围为67.8%~119%。相比于生活饮用水GB/T 5750.9—2006中2,4-D的测定用液液萃取后碱性条件下衍生的方法,该方法更为简便高效,检出限、精密度、准确度的结果也能满足实验室常规水质检测的要求,有实际应用价值。

Using liquid-liquid extraction-solid-phase extraction purification pre-treatment method,using a C8 liquid chromatography column,using methanol/phosphoric acid solution as the mobile phase,injecting 40μL,using a UV detector at 230 nm wavelength,using gradient elution for separation,the 7 kinds of phenoxycarboxylic acid herbicides were completely separated and quantified by external standard method.When the sampling volume is 250 mL and the constant volume is 1 mL,the detection limit is 0.04μg/L,and the lower limit of determination is 0.16μg/L.The correlation coefficients of the seven herbicides measured in the experiment ranged from 0.9996~0.9998.The standard addition test was carried out on groundwater,surface water,and domestic sewage.The measured relative standard deviation range was 1.9%~8.7%,and the standard recovery rate range was 67.8%~119%.Compared with the determination of 2,4-D in domestic drinking water GB/T 5750.9—2006,which is derived under alkaline conditions after liquid-liquid extraction,this method is simpler and more efficient,and the detection limit,precision,and accuracy are better.The results can also meet the requirements of routine water quality testing in laboratories,and have practical application value.