4,5-二溴邻硝基苯基荧光酮分光光度法测定铝

Spectrophotometric Determination of Aluminium with 4,5-Dibromo-2-nitro-phenylfluorone(DBoN-PF)

研究了在阳离子表面活性剂溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下，铝与４，５－二溴邻硝基苯基荧光酮（ＤＢｏＮ－ＰＦ）的显色反应。实验结果表明，在ｐＨ５０～５６的六次甲基四胺—盐酸的缓冲溶液中，铝与ＤＢｏＮ－ＰＦ形成１∶２络合物，其最大吸收峰位于５７９ｎｍ处，摩尔吸光系数ε＝１．５×１０５，铝含量在０～４μｇ／２５ｍｌ范围内符合比尔定律。当体系中引入氟化物后，可允许一定量的掩蔽剂存在，提高了方法的选择性。方法简便，快速，灵敏度高，用于铜合金、合金钢中铝的测定，结果满意。

The complex of Al(Ⅲ) and DBoN-PF is formed in the presence of CTMAB. The complex is investigated spectrophotometrically in the buffer solution of hexamethylene tetramine-hydrochloric acid. When the pH is within 5 0-5 6, the complex of Al(Ⅲ)-DBoNPF-CTMAB is formed with the maxinum absorption wavelength at 579 nm and the apparent molar absoroption coefficient is 1 5×10 5L\5mol -1 \5cm -1 .The molar ratio of Al to DBoNPF is 1∶2. Beer's law is obeyed in the concentration range of 0-4μg/25ml for Al(Ⅲ). Since fluoride is added in the system, the colour reaction allows presence of masking reagent. The method has good selectivity, and has been applied to determination of Al in alloy with satisfactory results.