用罗丹明B高灵敏分光光度法测定硅

Highly Sensitive Spectrophotometric Method for Determining Silicon With Rhodamine B

本文提出一种高灵敏水相显色的测硅的方法.在明胶、聚乙烯醇(PVA)和草酸存在的0.17mol/L HNO_3介质中,罗丹明B(RB)与硅钼杂多酸能形成离子缔合物,产生高灵敏显色反应、红外光谱表明,RB^+未受缔合物形成的影响.缔合物表观摩尔吸光系数ε_(585)=4.5×10~5L·mol^(-1)·cm^(-1),显色液稳定24h以上,干扰很少,无须萃取可直接测定硅.方法用于多种样品中硅的测定,结果令人满意.

A highly sensitive method for determining silicon by color reaction in water phase was established. In the 0. 17 mol/L nitric acid medium with gelatin, polyvinyl alcohol (PVA) and oxalic acid, a highly sensitive color reaction will occur between rhodamine B (RB) and silico-molybdic acid to form an ion-associate soluble complex. Infrared spectra show that the structure of RB+ is-not effected by the formation of the ion-associate complex. The apparent molar absorptivity of the ion-associate complex is 4. 5×105 L·mol-1·cm -1at 585 nm. The color is stable for at least 24 h, and the method has little interference. Silicon in various samples can be determined directly by the method without extraction with satisfactory results.