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.
出处
《冶金分析》
CAS
CSCD
北大核心
1999年第3期28-30,共3页
Metallurgical Analysis