吐温-80存在下用偶氮胂-Ⅲ分光光度法测定钙  

Spectrophotometric Determination of Calcium in the Presence of Tween-80

作　　者：李晓东[1,2] 

机构地区：[1]吉林建筑大学松辽流域水环境教育部重点实验室,吉林长春130118 [2]吉林建筑大学基础科学部,吉林长春130118

出　　处：《湿法冶金》2017年第6期525-528,共4页Hydrometallurgy of China

摘　　要：研究了吐温-80存在下偶氮胂-Ⅲ(ASA-Ⅲ)与Ca2+的显色反应。在pH=9.3的碱性介质中,Ca2+与ASA-Ⅲ形成n(Ca2+):n(ASA-Ⅲ)=1∶2的蓝色配合物。该配合物最大吸收波长位于652nm处,Ca2+质量浓度在0.1~1.2μg/mL范围内遵守比尔定律,方法表观摩尔吸光系数ε652nm=3.17×104 L/(mol·cm),检出限为25ng/mL,40种共存离子的存在对测定无影响。方法用于土豆、面粉、大米、豆粉等食物样品中钙的测定,简便、快速,测定结果与原子吸收光谱法测定结果基本吻合,较为满意。The color reaction of arsenazo-Ⅲ（ASA-Ⅲ）with Ca2＋in the presence of tween-80 was studied.In basic medium of pH=9.3,Ca2＋and ASA-Ⅲforms blue complex with a composition ratio of n（Ca2＋）∶n（ASA-Ⅲ）=1∶2.The maximum absorption wavelength of the complex locates at 652 nm.Beer＇s law is followed in the range of 0.1~1.2μg/mL of calcium,and the apparent molar absorptivity of the methodε652 nmis 3.17×104 L/（mol·cm）.The detection limit is 25 ng/mL.The 40 kinds of coexisting substances do not affect the determined of calcium.The method is applied to determine calcium in potato,wheat flour,rice and soybean powder samples,the results are good and agree with those of atomic absorption spectrometry.

关 键 词：分光光度法 偶氮胂-Ⅲ 吐温-80 食物 CA2+ 测定 

分 类 号：O657.3[理学—分析化学]