铝试剂分光光度法测定铝锭中微量三氧化二铝

Spectrophotometric Determination of Micro Amount of Alumina in Aluminum Ingot Samples with Aluminon

用金属铝与液态溴发生反应生成的AlBr3溶于甲醇、而Al2O3在无水条件下不与液态溴发生反应的不同化学行为特性，实现了Al与Al2O3的分离，采用铝试剂光度法测定铝锭中的微量AAl2O3。结果表明，在pH4．4的NaAc—HCI缓冲溶液中，铝与铝试剂形成的配合物在530nm处有最大吸收。Al2O3含量在0～3．0mg／L遵循比尔定律。方法检出限为0．005mg／L。建立的方法用于实际铝锭样品中Al2O3的测定，精密度（RSD，n=5）为3．50％～14．3％，加标回收率为98．9％～99、7％。

Based on the different chemical characteristics, in which resultant of AIBr3 from the reaction of metal aluminum with liquid bromine is soluble in absolute methanol and Al2O3 does not react with liquid bromine, the separation of metal aluminum from Al2O3 is realized. And also a method for the determination of micro amount of Al2O3 in aluminum ingot samples by spectrophotometry with aluminon as chromatogenic agent has been developed. Aluminum reacts with aluminon to form a complex with maximum absorption peak at 530 nm in NaAc-HCI buffer solution. Beer＇s law is obeyed in the range of 0 -3.0 mg/L for Al2O3. The method has been applied to the determination of Al2O3 in practical samples with recoveries of 98.9% -99.7% and precision of 3.50% - 14.3% RSD （ n =5）.