氯磺酚S两波长分光光度法测定铬（Ⅲ）和铝（Ⅲ）

在pH2.5～3.5的乙酸盐缓冲溶液中,在加热的条件下,氯磺酚S与铬(Ⅲ)和铝形成最大吸收在656.1nm和649.4nm的蓝色螯合物,吸收带重叠,光度测定时彼此干扰.当以参比波长λ_1=663.8nm,测定波长λ_2=648nm时测定铬,以λ_1=618.8nm和λ_2=678.0nm时测定,可用两波长分光光度法同时测定铬(Ⅲ)和铝,本文研究了显色反应的适宜条件,干扰离子的影响及消除方法.用于合成水样和废水中铬和铝的测定,得到了满意的结果.

DOUBLE-WAVELENGTH SPECTROPHOTOMETRIC METHOD FOR THE DETETMINATION OF CHROMIUM (III) AND ALUMINIUM (III)WITH SULFOCHLOROPHENOL S

In the acetate buffer solution of pH 2.5-3.5 and under the condition of heating sulfochlorophcnol S reacts with Chromium (III) and Aluminium (III) to form the blue chclatcs with the maximum absorbancc at 656 nm and 649 nm respectively. Their absorption bands arc overlapping and therefore it is interfering each other in the spcctrophotometric determination. When the reference wavelength A, = 663.8 nm and detection wavelength A2= 648.0 nm were used for determination of aluminium (III ) and A, = 618.8 nm, 2 = 678.0 nm were used for the determination of chromium (III ), the double-wavelength spcctrophotometric method can be applied for simultaneous determination of chromium (III) and aluminium (III). The work also investigated the suitable conditions of the colour reactions, the effects of the interfering ions and the method for eliminating the interference. The results of the method used is satisfactory for simultaneous determination of chromium (III) and aluminium (III) in synthetic water samples and waste water.