甲基紫褪色光度法测定电镀废水中微量的铜

研究了在HNO3介质 ,95℃沸水浴中 ,Cu2 + 催化过氧化氢氧化甲基紫褪色反应的适宜条件及影响因素 ,据此建立了动力学褪色光度法测定微量Cu2 + 的新方法。方法的线性范围为 0～ 12 0 μg L ,表观摩尔吸光系数为 2 88× 10 5L mol·cm ,最大吸收波长为 5 80nm ,方法的检出限为 1 79× 10 - 1 0 μg L。该法应用于电镀废水中铜的测定 ,结果令人满意。

DETERMINATION OF TRACE Cu2+ IN ELECTROPLATING EFFLUENT WITH METHYL VIOLET FADING PHOTOMETRY

It is investigated that Cu 2+ can catalyze the fading oxidation of methyl violet by hyderogen peroxide in HNO 3 medium at 95℃.On the basis of which,a new method of determining trace Cu 2+ is established,whose maximum absorptive wavelength is 580 nm,apparent molar absorptivity is 2.88×105 L/mol·cm;linear range is 0～120 μg/L for Cu 2+ and detection limit is 1.79×10 -10 μg/L.The method has been applied to the determination of Cu 2+ in electroplating effluent with satisfactory results.