在微乳液/离子液体协同增敏下测定样品中的硅

以OP(聚乙二醇辛基苯基醚)/正戊醇/正庚烷/水微乳液与1-丁基-3-甲基咪唑氯盐为介质,建立了硅的结晶紫-硅钼杂多酸光度分析法,研究了显色时间、微乳液与离子液体比例和用量、体系酸度、钼酸铵和结晶紫用量对显色反应的影响。结果表明,离子缔合物的最大吸收波长为545 nm,表观摩尔吸光系数为1.2×10~5L/(mol·cm),硅质量浓度在0.024~0.24 mg/L内符合朗伯-比尔定律。该方法的检出限为2.0×10~(-6)g/L,可用于自来水、雨水、钢样中微量硅的测定,相对标准偏差﹤3%,加标回收率为98%~106%。

Determination of silicon in samples by synergistic sensitizing micro-emulsion and ionic liquids

The crystal violet-silicon molybdenum heteropoly acid spectrophotometry has been established,using OP/n-C5H11OH/n-C7H16/H2O micro-emulsion and 1-butyl-3-methyl imidazole chloride salt as media.The influences of color development time,ratio and dosage of micro-emulsion and ionic liquid,the system acidity,dosages of ammonium molybdate and crystal violet on color development reaction are carefully studied.The results show that the maximum absorption wavelength of ion association is 545 nm,the apparent molar absorption coefficient 1.2×105 L/(mol· cm),and Si mass concentration in the range of 0.024-0.24 mg/L,complying with Lambert-Beer's law.The detection limit of this method is 2.0× 10-6 g/L.It can be used for the determination of trace silicon in tap water,rain water,and steel samples.Its RSD is less than 3％ and labeled recovery rate ranged from 98％ to 106％.