2-(2′-苯并噻唑偶氮)-7-(4-甲氧基偶氮)-1,8-二羟基萘-3,6-二磺酸的合成及与铝的显色反应

Synthesis of 2-(2′-Benzothiazolylazo)-7-(4-Methoxyphenylazo)-Chromotropic Acid and Its Chromagenic Reaction with Aluminium(Ⅲ)

合成一种新的显色剂2-(2′-苯并噻唑偶氮)-7-(4-甲氧基偶氮)-1,8-二羟基萘-3,6-二磺酸(BTAMoPACA).研究了试剂的结构和与Al(Ⅲ)的显色反应,结果表明:在pH为5.6～6.0的邻苯二甲酸氢钾-氢氧化钠缓冲介质中,Al(Ⅲ)与BTAMoPACA及溴化十六烷基三甲铵(CTMAB)形成1:3:1的三元络合物,其最大吸收波长为674 nm,表观摩尔吸光系数ε=3.04×105L·mol-1·cm-1.络合反应在20 min后趋向稳定,Al(Ⅲ)浓度在0～0.20 mg/L符合比尔定律.拟定方法应用于实际样品中Al(Ⅲ)的测定,获得较满意的结果.

A new chromatogeni6 reagent - （ 2 -benzothiazolylazo ） -7- （4-methoxyphenylazo） -chromotropic acid （BTAMoPACA） ihas been synthesized and its chromagenic reaction with aluminium （Ⅲ） has been studied. In the presence of buffer solution KHC8H4O4-NaOH （ pH 5.6 -6.0）, Al（Ⅲ） forms a triple complex with CT- MAB （cation surface active agent） and BTAMoPACA in composition of Al： R ： CTMAB = 1 ： 3 ： 1, Its apparent molar absorptivity is 3.04× 10^5 L·mol^-1·cm^-1 at 674 nm. Beer＇s law is obeyed in the range of 0 -0.20 mg/L for Al（Ⅲ）. The proposed method has been applied to the analysis of micro-amount of Al （Ⅲ） in sampies with satisfactory results.