Abstract： The beryllium copper intermediate alloy sample was dissolved by nitric acid to determine the content of aluminum. The pH of solution was adjusted to 6-7 using ammonia water. The iron and aluminum were precipitated in form of hydroxide. After filtration and washing, they were separated from matrix copper. The precipitation was dissolved with hydrochloric acid. In HAc-NaAc buffer solution at pH 5.0, aluminum reacted with 8-hydroxyquinoline to form complex, which was extracted with chloroform. The maximum absorption wavelength of complex was at 393 nm, and the apparent molar absorptivity was 6.45×103 L·mol-1·cm-1. In chloroform coloring solution, the Beers law was obeyed for aluminum ion with mass concentration of 0-4 000 μg/L. The interference ions such as iron and copper were removed by cupron-chloroform extraction before coloring. This method was applicable for the determination of 0.000 2 %-0.5 % aluminum in beryllium copper intermediate alloy. The results were consistent with those obtained by ICP-AES. The recoveries of standard addition were 98%-102%.
