摘要
在十二烷基硫酸钠存在下，于ｐＨ４８～７４的缓冲溶液中，２＿〔２＿（６＿甲基苯并噻唑）偶氮〕＿５＿二乙氨基苯甲酸（６＿Ｍｅ＿ＢＴＡＥＢ）与Ｃｏ（Ⅱ）发生显色反应，形成稳定的蓝紫色络合物，其组成为ｎＣｏ（Ⅱ）∶ｎ６＿Ｍｅ＿ＢＴＡＥＢ＝１∶２，最大吸收波长为６５０ｎｍ，ε为１３８×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ｃｏ（Ⅱ）质量浓度在０～０３２ｍｇ／Ｌ时服从比尔定律。方法可直接用于维生素Ｂ１２和含钴分子筛中微量Ｃｏ（Ⅱ）的测定，结果与原子吸收法相符。对于ｗ（Ｃｏ）＝０．８２％的含钴分子筛测定８次，其ＲＳＤ为１３４％。
In this paper, the study on chromogenic reaction of a new thiazolylazo reagent 2_ 2_(6_(methylbenzothiazolyl)azo _5_diethylaminobenzoic acid (6_Me_BTAEB) with cobalt (Ⅱ) is reported. In the presence of sodium dodecyl_sulfate, cobalt(Ⅱ) reacts with 6_Me_BTAEB in a buffer solution of pH 4.8～7.4 and forms a stable n Co(Ⅱ) ∶ n 6_Me_BTAEB =1∶2 blue_violet complex. Its maximum absorption at 650 nm with an apparent absorptivity of 1.38×10 5 L·mol -1 ·cm -1 . Beer′s law is obeyed in a range of 0～0.32 mg/L for Co(Ⅱ). The proposed method has been applied to the direct determination of Co in V B12 and molecular sieve containing Co with satisfactory results.
出处
《岩矿测试》
CSCD
北大核心
1997年第3期217-220,共4页
Rock and Mineral Analysis
基金
西安近代化学研究所科研基金
关键词
噻唑偶氮羧酸
试剂
钴
显色反应
determination of cobalt
2_ 2_(6_(methylbenzothiazolyl)azo _5_diethylaminobenzoic acid (6_Me_BTAEB)
