铬酸钡分光光度法和间接原子吸收法测定水中硫酸盐的比较

目的比较铬酸钡分光光度法和间接原子吸收法测定水中硫酸盐的异同。方法比较两种方法的标准曲线和回收率,并对12份地下水和地表水（硫酸盐浓度大于10.0 mg.L-1）分别用两种方法分析。同时进行两种方法精密度和准确度比较。结果两种方法的相关系数均大于0.999,回收率均满足分析要求。进行12份水样测定结果的配对t检验,t=0.13,P﹥0.05。对于10.0 mg.L-1的合成水样,铬酸钡法分光光度法测定相对误差为9.0%,而间接原子吸收法测定相对误差为0.4%。结论铬酸钡分光光度法在测定低浓度硫酸盐时,准确度和灵敏度较间接原子吸收法低,而大于10 mg/L时,两种方法都能得到较好的准确度和灵敏度。

A Comparison of Determination of Sulfate in Water by Chromium Acid Barium Spectrophotometry and Indirect Atomic Absorption Spectrometry

Objective To compare chromic acid barium spectrophotometry and indirect atomic absorption spectrometry in determining sulfate.Methods Compare the standard curve of two methods and recovery rate,and 12 groundwater and surface water（sulfate levels greater than 10.0 mg/L） with two methods were analyzed.And compare precision and accuracy of the two methods.Results The correlation coefficient of the two methods are larger than 0.999 and both of the recovery rate can meet the requirements of analysis.Water for 12 of the testing results,paired t test,t=0.13,P﹥0.05.For the synthesis of 10.0 mg/Lchromium water,the relative error of chromic acid barium spectrophotometry is 9.0%,while indirect atomic absorption spectrometry is 0.4%.Conclusion When determinating of barium sulfate in low concentration by chromium acid spectrophotometric method,the accuracy and sensitivity is lower than using indirect atomic absorption method.But when the concentration is more than 10 mg/L,the two methods can also get good accuracy and sensitivity.