硅钼黄分光光度法测定酸浸液中高浓度胶体二氧化硅含量

Silicon Molybdenum Yellow Spectrop Hotometric Method for Determination of High Concentration Silica in Acid Leaching Solution

探究用NaHCO3作为解聚剂、钼酸铵为显色剂测定高浓度酸性胶体二氧化硅含量的分光光度法,该方法是经典钼黄法的一种改进。通过对比实验,确定了实验过程中最佳搅拌破碎时间、反应时间、显色酸度、显色温度、显色时间,且明确实验的pH值和搅拌破碎程度(时间)需要严格控制。pH值为1.25(±0.05),二氧化硅质量浓度在12.5~150 mg/L范围内,选择吸收波长为410 nm,测定结果符合朗伯比尔定律;所建立的经典钼黄法线性回归方程的R2=0.9997,加标回收率在102.5%~111.4%之间,相对标准偏差为6.7%(n=5);以NaHCO3作为解聚剂的改进钼黄法线性回归方程的R2=0.9994,加标回收率在95.7%~97.2%之间,相对标准偏差为3.9%(n=5)。

A spectropHotometric method for the determination of colloidal silica using NaHCO3 as depolymerization agent and ammonium molybdate as chromogenic agent was studied.This method is an improvement of the classical silicon-molybdenum yellow spectropHotometry,and the optimum stirring and crushing time,reaction time,chromogenic acidity,chromogenic temperature and chromogenic time were determined in this paper.The PH value and degree(time)of agitation crushing need to be strictly controlled.When the pH value was 1.25(±0.05)and the mass concentration of silica was within the range of 12.5~150 mg/L,the uv absorption wave Length was 410nm,the results were in Line with the lamber Beer Law.The correlation coefficient of the Linear regression equation established by the classical silicon-molybdenum yellow spectropHotometry was 0.9997.The standard recovery was between 102.5%and 111.4%,and the relative standard deviation was 6.7%(n=5).The correlation coefficient of the linear regression equation of NaHCO3 as the depolymerization agent was 0.9994,the standard recovery was 95.7%~97.2%,and the relative standard deviation was 3.9%(n=5).