乙基紫-磷钼钒杂多酸分光光度法测定铁钙包芯线中的磷

Determination of Phosphorus in Calcium-Iron Cored Wire by Spectrophotometry with Ethyl Violet-Molybdovanadophosphoric Heteropoly Acid System

在非离子(O/W)型微乳液(OP/n-C5H11OH/n-C7H16/H2O)存在下,磷钼钒杂多酸与乙基紫在0.7—1.0mol/L硝酸介质中形成蓝色的离子缔合物,缔合物的最大吸收波长为612nm,表观摩尔吸光系数ε612为1.58×l05L.mol-1.cm-1,磷含量在0.03—0.4μg/mL范围内符合比耳定律,检出限为0.008μg/mL,用该方法测定铁钙包芯线中的磷,相对标准偏差小于5%,加标回收率在97.5%—101.5%,结果满意。

Ethyl violet with molybdovanadophosphoric heteropoly acid formed a blue ion-association complex in 0.7—1.0mol/L nitric acid medium in the non-ion（O/w） of microemulsion（OP/n-C5H11OH/n-C7H16/H2O）.The association matter maximum absorption was at 612nm,and Beer＇s law was obeyed for 0.03—0.4μg/mL of phosphorus,and the molar absorptivity was1.58×l05L·mol^-1·cm^-1.The lowest detection limit was 0.008μg/mL,The method was applied to the determination of phosphorus in iron-calcium cored wire samples,the relative standard deviation was less than 5%,and the recovery was in the range of 97.5%—101.5% with a satisfaction results.