摘要
国内外光度法测定铬常用二苯基碳酰二肼法。由于二苯基碳酰二肼溶液不稳定,需要避光保存,而且易被空气氧化逐渐变黄,酸度对试剂的影响很大,基于上述原因,使该方法的应用受到了一定的限制。本文研究了两种新的偶氮氯膦类显色剂(磺胺偶氮氯膦和氨基G酸偶氮氯膦)与重铬酸根离子的褪色反应,基于此褪色反应拟定了测定铬(Ⅵ)的新方法。该方法反应酸度高,操作简便、快速,重现性好。摩尔吸光系数分别为2.
The colour-fading reaction of two new chlorophosphonazo type reagents (sulfonamide chlorophosphonazo and amino G acid chlorophosphonazo) with Cr_2O_7^(2-) anion is described, and a method is proposed for the determination of Cr(Ⅵ) based on the fading reaction. The method is simple and rapid. Their molar absorptivities are 2.8×10~4 and 3.0×10~4 respectively. Beer's law is obeyed from 2.0 to 11.0μg in 25ml. Cr (Ⅵ) in standard samples of chromium steel was determined and good results were obtained.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1989年第4期349-351,共3页
Chinese Journal of Analytical Chemistry
关键词
重铬酸根
偶氮氯膦
显色剂
褪色
Colcui-fading reaction
Sulfonamide chlorophosphonazo
Amino G acid chlorophosphonazo
