二溴对甲基偶氮磺光度法测定镁砂中钙  

Spectrophotometric Determination of Calcium in Magnesite with Sulfonazo-DBM

作　　者：高琳[1] 周菊香[1] 钟国秀[2] 

机构地区：[1]江汉大学化学与环境工程学院,武汉430056 [2]湖北省机电研究设计院测试中心,武汉430070

出　　处：《江汉大学学报（自然科学版）》2006年第2期31-32,共2页Journal of Jianghan University：Natural Science Edition

摘　　要：研究了新显色剂二溴对甲基偶氮磺与钙的反应,建立了直接测定镁砂中钙的光度分析方法.在0.4mol/L硝酸介质中钙与二溴对甲基偶氮磺形成蓝色配合物,最大吸收波长624nm,表观摩尔吸光系数为3.5×10^4L/（mol·cm）,钙含量在2～10μg/25mL范围内符合比耳定律,显色反应具有良好的选择性,主要共存离子有较大允许量,可用于镁砂中钙的测定.The chromogenic reaction between the new reagent dibromo-p-methylsulfonazo and calcium was studied. In 0.4 mol/L HNO3 medium, calcium reacts with the reagent to form a blue complex which exhibits an absorption maxima at 624 nm with a molar absorptivity of 3.5×10^4L/（mol·cm）, Beer＇ s law is obeyed for 2 - 10 lag of calcium in 25 mL of solution. Most of common coexisting ions caused not interferences in the determination of calcium. The results obtained by this method in the analysis of some samples ofmagnesite was consistent with certified value. The RSD is 3.55% - 5.00%. This method has been used to determine calcium in magnesite.

关 键 词：光度法 钙 二溴对甲基偶氮磺 镁砂 

分 类 号：O657.32[理学—分析化学] O614.2[理学—化学]