同时测定锰和铬的增敏碘量法研究  

Study on an Iodometric Amplification Method for the Simultaneous Determination of Manganese and Chromium

作　　者：张明浩 詹国平 雷振春 

机构地区：[1]长沙工业高等专科学校冶化系,长沙410012 [2]湖南水口山矿务局分析测试中心

出　　处：《冶金分析》1999年第3期28-30,共3页Metallurgical Analysis

摘　　要：介绍了同时测定微克量级锰和铬的简单快速的增敏碘量法．Ｍ（Ⅶ）和Ｃｒ（Ⅵ）用Ｎａ２ＳＯ３预先还原；在ｐＨ３．０的乙酸盐介质中，Ｍｎ（Ⅱ）和Ｃｒ（Ⅲ）可用过量ＫＩＯ４氧化，当介质中有Ｈ２Ｐ２Ｏ２－７掩蔽Ｃｒ（Ⅲ）时，则只有Ｍｎ（Ⅱ）被氧化；过剩的ＩＯ４用铂酸根掩蔽，加入ＫＩ后，用Ｎａ２Ｓ２Ｏ３滴定游离出来的Ｉ２．此法成功地测定了不同样品中的锰和铬，相对ＥＤＴＡ滴定法，对锰和铬的测定，分别增敏２０和１２倍．A simple, rapid, amplified iodometric method for the simultaneous titrating micro amounts of manganese and chro mium was developed. Manganese (Ⅶ) and chromium (Ⅵ)were reduced by Na2SO3 in advance; In the medium of acetatebuffer solution, pH 3.0, Mn (Ⅱ) and Cr (Ⅲ) were oxidized by an excess of KIO4, in the presence of H_2P_2O_2-_7, onlyMn (Ⅱ) was oxidized; the excess of IO_4 could be masked by molybdate. After adding KI, the liberated iodine was titratedby Na_2S_2O_3. The method has been applied to determine manganese and chromium in the different samples. Compared withthat of EDTA titration method, the sensitivity of this method was increased about 20 times (for Mn) and 12 times (for Cr)respectively.

关 键 词：锰 铬 增敏反应 增敏碘量法 同时测定 滴定分析 

分 类 号：O614.711[理学—无机化学] O614.611[理学—化学]