1979年以来华东师范大学有机合成研究室先后提出用偶氮氯膦mA、偶氮氯膦mN、偶氮氯膦pN等不对称变色酸双偶氮膦酸型试剂作为稀土元素的新显色剂。其中后两种试剂在一定的介质中只与铈组稀土元素显色,从而实现了在钇组稀土元素共存的情况下,直接测定球墨铸铁中的铈组稀土元素。本文对偶氮氯 Since 1979, East China Normal University Organic Synthesis Laboratory has proposed with chlorophosphonazo mA, chlorophosphonazo mN, chlorophosphonazo pN and other asymmetric chromogenic acid disazo-phosphonic acid reagent as a rare earth element of the new reagent . Among them, the latter two reagents only reacts with the rare earth elements in the cerium group in a certain medium, so that the rare earth elements in the cerium group in the ductile iron can be directly measured under the coexistence of the rare earth elements in the yttrium group. In this paper, azo chlorine