镓与对乙酰基偶氮羧-m的显色反应及其应用研究

Study on Colour Reaction Between Gallium and p-acetylcarboxylazo-m and Its Application

研究了对乙酰基偶氮羧-m与Ga（Ⅲ）的显色反应,建立了分光光度法测定镓的新方法.在pH=2.0的酸性介质中,镓与对乙酰基偶氮羧-m形成1∶2的有色络合物,最大吸收波长位于681 nm,表观摩尔吸光系数6ε81=1.14×10^5L.mol-1.cm^-1,检出限为0.73μg/L,线性范围为1.0～11.0μg/25 mL.方法应用于煤和煤矸石中微量镓的测定,获得了满意的结果.

The colour reaction between gallium and p - acetylcarboxylazo - m is studied in this paper. In the acid medium of pH 2.0, p - acetylcarboxylazo - m and gallium form a coloured complex with mole ratio of 1：2. The maximum absorption wavelength is at 681 nm with an apparent molar absorptivity of 1.14×10^5L.mol-1.cm^-1 The detection limit is 0.73μg/L and the linear range is 1.0 ～ 11.0 μg/25 mL of gallium. The method has been applied to the determination of microamount of gallium in coal and shale with satisfactory results.