1.Physical and Chemical Testing Laboratory of Lanzhou Jinchuan New Material Technology Company,Jinchang 737100,China; 2. Powder Material Co.,Ltd. of Jinchuan Group,Jinchang 737100,China
Abstract：This paper investigated the optimum experimental condition for the determination of sulfate by turbidimetric method and established the determination method of sulfate in cobalt nitrate solution. In dilute hydrochloric acid,when the temperature was 50℃,SO42- with Ba2+ reacted to form BaSO4 fine particles. In the presence of a protective agent (OP emulsifier-ethanol solution),such fine particles can be uniformly suspended in the solution and at the wavelength of 390 nm,sulfate concentration and absorbance established a good linear relationship. Experimental results showed that the optimum dosage of stabilizer was 5 mL,the turbidity value was stable within 40 min at the temperature of 50-60 ℃,the determination of sulfate ranged 1-8 μg/mL,and the addition standard recoveries of sample were in the range of 95%-105%. The proposed method was used in the analysis of cobalt nitrate solution,and the determined values of SO42- were consistent with those obtained by ion chromatography.
