【摘要】 研究提出镨 ( ) - DBC-偶氮氯膦 -磷酸 - EDTA新体系光度法测定贵金属合金中微量镨。反应体系生成 α型蓝色配合物的 λmax=650 nm,灵敏度高 ,摩尔吸光系数 ε=0 .93× 1 0 5L·mol-1·cm-1,镨浓度在 0～ 50 μg/2 5ml范围内符合比耳定律 ,方法选择性强 ,有较好的适用性 ,用于分析银合金中镨 ,标准偏差 S≤ 0 .0 1 1 ,相对标准偏差 RSD≤ 1 .97%。更多还原

【Abstract】 A new color reaction of Pr(Ⅲ) with chlorophosphonazo DBC using EDTA as complexing reagent was studied. A stable blue colored complex is formed in a dilute phosphoric acid medium. Its absorption maxima lies at 650nm with a molar absorptivity of 9.3×10 4L·mol -1 ·cm -1 . Beer′s law holds over the range of 0~50μg/25ml. This method has been applied successfully to the determination of micro amounts of praseodymium in silver alloys. The standard deviation ( S ) and RSD of the method are found to be 0.010 and 1.97%. The method is proved to be of high sensitivity and selectivity.更多还原