萃取分离8-羟基喹啉分光光度法测定铝

运用萃取分离8-羟基喹啉分光光度法测定微量铝。研究了8-羟基喹啉与Al~(3+)发生显色反应的条件,对该法的原理、酸度、还原剂的选择及用量、波长、灵敏度等进行了探究,结果表明:试剂与Al~(3+)在pH4.8的乙酸-乙酸钠缓冲溶液中可形成稳定的黄色络合物,络合物在波长390 nm处,表观摩尔吸光系数为ε=6.7×10~3L·mol~(-1)·cm~(-1),在10 mL萃取液中,Al~(3+)浓度在0～25μg范围内符合比耳定律,络合物可稳定4 h以上,回收率98.1%～101%。该法较传统的铬天青S法影响因素少,稳定性好,可用于工业硅及高纯硅铁等样品中微量铝的测定。

DETERMINATION OF ALUMINUM IN EXTRACTION SEPARATION 8-HYDROXYQUINOLINE SPECTROPHOTOMETRY METHOD

Using the extraction separation 8-hydroxyquinoline spectrophotometry to determine trace aluminum.The article researches the condition that 8-Hydroxyquinoline and Al^3＋ color reaction occurs,and probes into the principle,acidity, choice of reductant and dosage,wave length,sensitivity of this method.The results show：in the pH4.8 HAC-NaAC buffer solution,reagents and Al^3＋ can form stable yellow complex compound,and the complex compound in 390nm wavelength,the apparent molar absorptivity isε=6.7×10^3 L·mol^-1·cm^-1,in the 10 mL extraction solution,the concentration of Al^3＋ in the range of 0～25μg accords with Beer＇s law,the complex compound can be stabilized for more than 4 hours,and the recovery rate is between 98.2%～101%.Compared with the traditional chromazurine S method,this determining method has less influence and better stability,it can also be used in samples such as industrial silicon and high-purity ferrosilicon to determine trace aluminum.