铬酸钡法测定硫酸根的干扰因素研究

Interference factor in sulfate determination by barium chromate spectrophotometry

为了探明有机物和金属离子对铬酸钡光度法测定硫酸根的影响,选取不同种类的有机物(葡萄糖、尿素、柠檬酸、叔丁醇和正丁醇)和金属离子进行比对试验。结果表明:葡萄糖对硫酸盐测试干扰最大,在SO42-浓度和葡萄糖浓度分别为200 mg/L和3 000 mg/L的条件下,硫酸盐回收率仅为58.7%,硫酸盐回收率随葡萄糖浓度的增大而降低;尿素、柠檬酸、叔丁醇和正丁醇对硫酸盐测定结果没有显著影响。在SO42-浓度、葡萄糖和金属离子(存在CuSO4、Ag2SO4、Ni Cl2、CoCl2、Mn Cl2、FeSO4)浓度分别为200 mg/L、3 000mg/L和20 mg/L的条件下,硫酸盐回收率分别为65.8%、71.5%、62.3%、65.2%、86.7%和78.5%。

Organic matter( glucose,urea,citric acid,tert-butanol,n-butanol) and mental ions were selected for comparison test to analyze their influences on sulfate determination by barium chromate spectrophotometry.The results showed that glucose had the biggest interference with sulfate test. Sulfate recovery rate decreased with increasing concentration of glucose and it was only 58.7% when SO42-= 200 mg/L and glucose = 3 000 mg/L.Urea,citric acid,tert-butanol and n-butanol had no significant effect on the sulfate determination. When SO42-= 200 mg/L and glucose = 3 000 mg/L,the sulfate recovery rates in the presence of 20 mg/L CuSO4,Ag2 SO4,Ni Cl2,CoCl2,MnCl2 and FeSO4 were 65.8%,71.5%,62.3%,65.2%,86.7% and 78.5%,respectively.