论文部分内容阅读
本文报告用5-Br-PADAP作显色剂,研究在水一乙醇介质中测定铬(Ⅲ)的条件,确定了铬(Ⅲ)与5-Br-PADAP生成暗兰紫色络合物的适宜pH为4.0-6.0,其最大吸收峰位于600nm,摩尔吸光系数为7.93×10~41.mol~(-1)·cm~(-1),遵守比耳定律的浓度为0-15 ug铬(Ⅲ)/25 ml.试验45种共存离子中,仅等量的铁(Ⅲ)、铜(Ⅱ)、钴(Ⅱ)、镍(Ⅱ)、镓(Ⅲ)铟(Ⅲ)和铊(Ⅲ)有干扰.本法用于工业废水中铬(Ⅶ)和总铬的测定,结果良好,其变动系数为2.5%回收率均在95%以上.
In this paper, the conditions of determination of chromium (Ⅲ) in water-ethanol medium were studied by using 5-Br-PADAP as chromogenic reagent. The suitable pH of the complex formed between chromium (Ⅲ) and 5-Br- Is 4.0-6.0, the maximum absorption peak is at 600nm, the molar extinction coefficient is 7.93 × 10 ~ 41.mol -1 cm -1, and the Beer’s Law concentration is 0-15 μg chromium (Ⅲ ) / 25 ml. Of the 45 coexisting ions, only the equivalent amounts of iron (Ⅲ), copper (Ⅱ), cobalt (Ⅱ), nickel (Ⅱ), gallium (Ⅲ), and thallium This method was applied to the determination of chromium (Ⅶ) and total chromium in industrial wastewater with good coefficient of variation of 2.5% and recoveries above 95%.