痕量铝测定的直接比色法

Determination of Trace Amount of Al by Using Direct Spectrophtometric Method

分取25mg试样,铁用抗坏血酸还原,不经分离,直接用铬天青S显色进行测定。借6次甲基四胺及盐酸的缓冲作用,把溶液的pH控制在5.0±0.3,铝与铬天青S生成紫红色络合物,最大吸收波长为550μm。

The Trace amount of Al within the range of 0.004% - 0.020% in the low alloy steel was determined by using a spectrophtometric method. Iron in the sample (25 mg) was reduced by ascorbic acid without separation. The absorptance of red complex of Al with chromazurols in a buffer solution pH 5.0±0.3 was measured at 550μm.