制造电机用的铜银合金,含银0.1～0.25%,余量为铜。本文采用玫瑰红银试剂光度法测定银,方法简单,适用于工厂分析。一主要试剂对二甲氨基苄又罗丹宁(玫瑰红银试剂)乙醇溶液:0.01%。银标液:10μg ml~(-1)。二分析步骤称取试样0.2克置于100毫升两用瓶中,加入18毫升硝酸(1+2),低温溶解后,煮沸除尽氮的氧化物冷却,用水稀释至刻度,摇匀。吸取5毫升试液:置于50毫升量瓶中,加5.0毫升乙醇,滴加氢氧化钠溶液(5%)至刚有浅蓝色沉淀出现,加1～2滴硝酸(1+9)至沉淀恰溶解,溶液清亮,加入20毫升硝酸(3+197),5毫升玫瑰红银试剂溶液,用水稀释至刻度,摇匀。放置5～10分钟。参比液:称0.2克纯铜,按分析步骤操作制备。用3厘米比色皿,于波长470nm处测定吸光度。检量线的绘制称取纯铜0.2克,按分析步骤溶解、稀释。吸取试液5毫升6份,分别置于50毫升量瓶中,分别加入 Manufacture of copper and silver alloy motor, silver 0.1 to 0.25%, the balance of copper. In this paper, rose silver reagent photometric method for the determination of silver, the method is simple, suitable for factory analysis. A main reagent of dimethylamino benzyl rhodanine (rose red silver reagent) ethanol solution: 0.01%. Silver standard solution: 10μg ml ~ (-1). Two analysis steps Weigh 0.2 g sample was placed in 100 ml dual-use bottle, add 18 ml of nitric acid (1 +2), dissolved in low temperature, boil off the nitrogen oxide cooling, diluted with water to the mark, shake. Pipette 5 ml test solution: placed in 50 ml volumetric flask, add 5.0 ml of ethanol, sodium hydroxide solution was added dropwise (5%) to just pale blue precipitate appears, add 1 to 2 drops of nitric acid (1 +9) to The precipitate just dissolved, the solution clear, add 20 ml of nitric acid (3 + 197), 5 ml rose red silver reagent solution, diluted with water to the mark, shake. Place 5 to 10 minutes. Reference solution: 0.2 grams of pure copper, prepared according to analytical procedures. With 3 cm cuvette, absorbance was measured at a wavelength of 470 nm. Weighing the calibration curve draw 0.2 grams of pure copper, according to the analysis steps to dissolve, diluted. Pipette 5 ml of test solution 6, were placed in 50 ml volumetric flask, were added