离子色谱法与滴定法测定水溶肥料中亚磷酸盐含量的试验研究

Experimental Study on the Determination of Phosphite Content in Water-Soluble Fertilizers by Ion Chromatography and Titration

采用离子色谱法和常规滴定法测定水溶肥料中亚磷酸盐(以HPO32-计)的含量,考察了两种方法的精密度、加标回收率和离子色谱法的检出限。结果表明:滴定法测定结果的相对标准偏差(RSD)为1.04%~1.26%,加标回收率为90.20%~96.10%;离子色谱法测定时,亚磷酸的质量浓度在1.0~50.0μg/m L与峰面积呈线性关系,方法的检出限为40 mg/kg,RSD为0.78%~1.07%,加标回收率为95.20%~98.60%。两种方法均可满足水溶肥料中亚磷酸盐含量的测定要求,离子色谱法的测定结果更准确,操作更快捷。

Ion chromatography and conventional titration methods are used to determine the content of phosphite(calculated as HPO 2-3)in water-soluble fertilizers.The precision and spiked recovery rate of two methods as well as the detection limit of ion chromatography are investigated.The results show that the relative standard deviation(RSD)of the titration method is 1.04%to 1.26%,and spiked recovery rate is 90.20%to 96.10%.When measured by ion chromatography,the mass concentration of phosphite ranges from 1.0 to 50.0μg/mL has a linear relationship with peak area.The detection limit of ion chromatography is 40 mg/kg,RSD is 0.78%-1.07%,and the recovery rate of the spiked sample is 95.20%-98.60%.Both methods can meet the requirements for determining the content of phosphite in water-soluble fertilizers,and ion chromatography provides more accurate results and faster operations.