论文部分内容阅读
一、方法提要: 采用Zn(Ac)_2溶液沉淀硫化物,其滤液在碱性溶液中通空气氧化生成褐色对苯二醌,然后比色。 二、试剂与仪器 ①6N NaOH液; ②5％Zn(Ac)_2液; ③对苯二酚标准液(1.000克/升):用分析天平准确称取纯对苯二酚1.000克,加水溶解,转入1000毫升容量瓶内,加入6N NaOH液100毫升,用水稀释至刻度,充分摇动; ④72型分光光度计 三、操作步骤 ①标准曲线的绘制:用干净吸管分别吸取对苯二酚标准溶液0.0、0.5、1.0、1.5、2.0、3.0、4.0、5.0于八只100毫升容量瓶内,每只容量瓶内加6N NaOH液10毫升,加水约40毫升。各容量瓶同时通入半水煤气10分钟(通气速度以见连续出现一个个气泡为宜),加2毫
First, the method summary: The use of Zn (Ac) _2 solution precipitation sulfide, the filtrate in the alkaline solution by air oxidation of brown p-benzoquinone, and colorimetric. Second, reagents and equipment ① 6N NaOH solution; ② 5% Zn (Ac) _2 liquid; ③ hydroquinone standard solution (1.000 g / L): Accurately weigh pure hydroquinone 1.000 g with analytical balance, Into a 1000 ml volumetric flask, add 6N NaOH solution 100 ml, dilute to the mark with water, shake well; ④72 spectrophotometer three steps ① standard curve drawing: with a clean pipette were hydroquinone standard solution 0.0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0 In eight 100 ml volumetric flasks, add 10 ml of 6N NaOH solution to each volumetric flask and add about 40 ml of water. Each volumetric flask at the same time access to semi-water gas for 10 minutes (ventilation rate to see one after another bubble is appropriate), plus 2 milliliters