3,5-二溴-4-偶氮变色酸苯基荧光酮与铝显色反应及应用

Color Reaction of Aluminum (Ⅲ) with DBACPF and Its Application

研究了在阳离子表面活性剂ＣＴＭＡＢ存在下，Ａｌ（Ⅲ）与３，５＿二溴＿４＿偶氮变色酸苯基荧光酮（ＤＢＡＣＰＦ）的显色反应条件和光度性质。在ｐＨ６０的ＨＡｃ＿ＮａＡｃ缓冲介质中，Ａｌ（Ⅲ）与试剂形成１∶２的红色配合物，最大吸收峰位于５６０ｎｍ处，表观摩尔吸光系数为１２５×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ａｌ（Ⅲ）的质量浓度为０～０２ｍｇ／Ｌ时符合比尔定律。拟定方法用于铝黄铜及石灰石样品中铝的测定，结果与标准值相符。

In pH 6.0 HAc_NaAc buffer solution and in the presence of cetyl trimethyl ammonium bromide (CTMAB), aluminum (Ⅲ) reacts with 2,3,7_trihydroxy_9_[3,5_dibromo_4_(1,8_dihydroxy_3,6_disulfonic acid) naphtha_oleneazo] phenyl fluorone (DBACPF) to form a 1∶2 red micellar complex. The maximum absorbance is at 560 nm with molar absorption of 1.25×10 5 L·mol -1 ·cm -1 . Beers law is obeyed in the concentration range of 0～2.0 mg/L for Al(Ⅲ). The method has been applied to the determination of Al in brass and limestone samples with satisfactory results.