改进铬天青S光度法测定饮用天然矿泉水中铝

Determination of aluminum in natural mineral water for drinking by modified chrome azurol S spectrophotometry

采用分光光度法研究了铬天青S(CAS)-溴化十六烷基吡啶(CPB)-聚乙二醇辛基苯醚(OP)-铝(Al)四元络合物的显色反应,并确定了最佳试验条件。结果表明:显色反应在pH7.0的HAc-NaAc缓冲溶液中进行,此时最大吸收波长位于630nm处,最佳显色时间为20min。回归方程为y=0.2235x+0.2549,相关系数r=0.9995,改进后的方法测定天然饮用矿泉水中铝的含量,相对标准偏差为3.36%～3.77%,回收率为99.2%～100.1%

Based on the chrome azurol S spectrophotometry, the determination of aluminum in natural mineral water for drinking by ultraviolet spectrophotometry was studied. The results showed that the chrome azurol S dosage was the most essential factor and the 4-complex compound＇s maximum characteristic absorption in the buffer solution of HAc-NaAc （pH 7.0） was at 630 nm wavelength, and the optimum chromogenic time was 20 min. The linear regression equation was y = 0.2235x ＋ 0.2549 and the correlation coefficient was 0.9995. This modified method had been applied to the determination of aluminum in natural mineral water for drinking, the relative standard deviations were 3.36 % - 5.77 %, and the recoveries were 99.2 % - 100.1%.