钴的1-(6-溴-2-苯并噻唑)-3-(5-溴-8-喹啉)-三氮烯分光光度测定法

Determination of Cobalt by Spectrophotometry Using a New Reagent, 1-(6-bromo-2-benzothiazolyl)-3-(5-bromo-8-quinolyl)-triazene

目的合成一种新试剂,即1-(6-溴-2-苯并噻唑)-3-(5-溴-8-喹啉)-三氮烯(BBTBQT),并应用于钴的测定。方法通过重氮化和偶联反应合成试剂,经纯化、表征后,研究了在溴化十六烷基吡啶(CPB)存在下,该试剂与钴的显色反应的条件。结果在pH=9.0的硼砂缓冲介质中,该试剂与钴形成2∶1蓝色络合物,其最大吸收波长为640nm,表观摩尔吸光系数为1.55×105L/(mol·cm),钴的浓度在0～0.28mg/L的范围内符合比尔定律。该方法应用于维生素B12注射液和水系沉积物中的微量钴的测定,平均相对误差为1.9%～5.8%,RSD为1.7%～3.8%。结论BBTBQT应用于样品中微量钴的测定,选择性较高,方法灵敏、准确、简便。

Objective To synthesize a new reagent, 1-(6-bromo-2-benzothiazolyl)-3-(5-bromo-8-quinolyl)-triazene (BBTBQT) and apply to the determination of cobalt. Methods The reagent had been synthesized by diazotization and coupling reaction. After purification and characterization, BBTBQT was tested for its color reaction conditions with cobalt in the presence of cetylpyridinium bromide (CPB). Results In the presence of borax buffer solution at pH value of 9.0, the reagent reacted with cobalt to form a blue stable co...