偶氮氯膦Ⅲ分光光度法测定硅铁中钙
来源期刊：冶金分析2010年第7期
论文作者：钟国秀 黄清华 杨浩义
文章页码：69 - 71
关键词：偶氮氯膦Ⅲ； 分光光度法； 钙； 硅铁
Key words：chlorophosphonazo Ⅲ； spectrophotometry； calcium； silicon iron
摘 要：研究了偶氮氯膦Ⅲ与钙的显色反应,建立了测定硅铁中钙含量的分光光度分析方法。试验并确定了最佳反应条件,结果表明:在pH 10.0的NH3·H2O-NH4Cl缓冲介质中,钙与偶氮氯膦Ⅲ形成绿色络合物,在波长672 nm处有最大吸收,且显色程度与钙浓度成正比。钙质量浓度在0.072~1.00μg/mL范围内符合比尔定律,方法的检出限为0.022μg/mL。在加入掩蔽剂三乙醇胺与邻菲啰啉掩蔽铝、锰、铁后,用于普通硅铁标准样品中钙的测定,结果同认定值相符,相对标准偏差(RSD)在2.0%左右。
Abstract: The coloring reaction between chlorophosphonazoⅢ and calcium was studied,and a determination method of calcium in silicon iron by spectrophotometry was established.The optimal reaction conditions were investigated and obtained.The results showed that in NH3·H2O-NH4Cl buffer solution at pH 10.0,the calcium could form green complex with chlorophosphonazoⅢ.The complex had maximum absorption at 672 nm,and the absorbency was in direct proportion to the concentration of calcium.Beer’s law was obeyed for calcium in the range of 0.072-1.00 μg/mL.The detection limit of method was 0.022 μg/mL.After triethanolamine and o-phenanthroline for masking aluminum,manganese and iron was added,the proposed method was applied to the determination of calcium in common silicon iron standard samples.The results were consistent with the certified values,and the relative standard deviation (RSD) was about 2.0%.
