摘要
利用硝酸溶解试样，在强酸性介质中，通过加入还原剂盐酸羟胺，将钼（V1）还原为钼（V），准确加入过量的EDTA标准溶液，使之与钼（V）形成1：1的稳定络合物，剩余的EDTA在pH值为6的乙酸-乙酸钠缓冲溶液中，用半二甲酚橙为指示剂，用铅标准溶液返滴定，根据消耗铅标准溶液的毫升数，来间接测定出钼铁样品中的钼含量。通过选择试验条件，有效的避免铁、铜、锰等杂质的干扰；分别选择4种不同的标准物质，进行8次试验，将测定值与标准值比较，差值满足GB／T5059．1-2014标准允许差要求，相对标准偏差小于1．0％，测定结果满意。
In order to return Mo（VI） to Mo（V）, the nitric acid dissolve sample was used and hydroxylamine hydrochloride was added as reductant into highly acidic media; adding exactly extra EDTA standard solution together with Mo（V）, stable complex clathrate for 1：1 was formed; excess EDTA in acetic acid-sodium acetate with 6 of pH value, in which semi xylenol orange was used as indicator, lead standard solution was used to return titration. According to the consumed milliliter number of lead standard solution, the Mo content of ferro-molybdenum sample can be measured indirectly. The impurities of iron, copper, manganese can be avoided effectively through the selected test conditions. Four different kinds of standard substance were selected, tests were done for eight times, compare the determination value and the standard value were compared. If the difference value accords with the deviation of standard GB/T5059.1-2014, and the relative standard deviation is less than 1.0%, the results are satisfactory
作者
董亚红
Dong Yahong(CRRC China Datong Electric Locomotive Co.,Ltd.Datong, Shanxi,03703)
出处
《现代科学仪器》
2017年第5期126-129,共4页
Modern Scientific Instruments
关键词
容量法
EDTA
钼铁
试验研究
Volumetric method, EDTA, Ferro-molybdenum, Experimental study
