关键词: 分析化学 , 硅(IV) , 分光光度法 , 硅钼蓝 , 钼酸铵 , 水样

Abstract: Silicon (IV) reacts with ammonium molybdate to form silicomolybdate yellow at hydrochlo?ric acid concentration of 0.050 mol· L-1. Silicomolybdate yellow is reduced by ascorbic acid and forms silicomolybdate blue at hydrochloric acid concentration of 1.48 mol· L -1. The maximum absorption of the complex exhibits at 346 nm and the molar absorptivity is ε346 nm = 4.5 X 104 L ? mol-1 ? cm-1. Beer，s law is obeyed over the range of 0.1?2.8 μg? mL-1 of silicon (IV) . The effect of thirty-six common co-existing substances on the determined results of silicon (IV) was observed. The method was successfully used in the determination of silicon in environmental water sample with satisfactory results.

Key words: analytical chemistry , silicon (IV) , spectrophotometry , silicomolybdate blue , ammonium molybdate , water sample