近年来出现的一系列新偶氮氯膦型显色剂,在稀土元素的测定方面比偶氮胂型显色剂有诸多的优越性,例如灵敏度高、选择性较好、试剂及络合物稳定等。氯膦型显色剂之所以有良好的性能,是因为具有良好的成盐基团——膦酸基,同时在偶氮基对位存在氯原子,它既增强膦酸基团的酸性又促进了偶氮基对稀 In recent years, a series of new chlorophosphonazo-type developers, rare earth elements in the determination of arsenazo-type than the developer has many advantages, such as high sensitivity, better selectivity, reagents and complexes Stability and so on. The reason why the good performance of the chlorophosphonate-based color developer is that it has a good salt-forming group, a phosphonic acid group, and a chlorine atom at the para-azo group, which not only enhances the acidity of the phosphonic acid group but also promotes Azo-based thinning