摘要
在硫酸介质中,溴化钾催化下,碘酸根对二甲基黄有褪色作用,且褪色的程度与碘酸根的量有关,从而建立了光度法测定碘的新方法。方法的最大吸收波长为515nm,表观摩尔吸光系数为3.1×104L·mol-1·cm-1,碘浓度在0～20μg/10ml范围内符合比耳定律,检出限为1.02×10-8g·ml-1。方法简单、快速、选择性好、灵敏度高,用于测定碘盐中碘的含量,结果满意。
In a 0.1mol·L^(-1) H_2SO_4 medium, and in the presence of 0.05mol·L^(-1) of KBr, dimethyl yellow (DMY) is oxidized by iodate, leading to a color fading of DMY, and the decrease of color intensity (ΔA, measured at 515nm) keeps a linear relationship with the concentration of IO^-_3 ion (expressed as I_2) in the range from 0 to 20μg per 10ml of solution. The apparent molar absorptivity is 3.1×10~4L·mol^(-1)·cm^(-1), and the detection limit is 1.02×10^(-8)g·ml^(-1). This method is characterized by its sensitivity, selectivity, simplicity and rapidity. It has been applied satisfactorily to the determination of iodate in table salt.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2004年第7期384-386,共3页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
关键词
褪色光度法
二甲基黄
碘酸盐
食盐
Photometry
Color fading reaction
Dimethyl yellow
Iodate
Table salt
