Yuhui CH-AM is a premium grade macroporous amino phosphonic chelating resin based on styrene-divinylbenzene (DVB) copolymers with standard Gaussian particle size distribution. Due to its special amino phosphonic function group, CH-AM has high selectivity to capture heavy metals and alkaline earth cations. CH-AM is developed to be used for brine purification for chloralkali membrane cells by removal of Ca²⁺, Mg²⁺, Ba²⁺, Sr²⁺. The selectivity of CH-AM should follow sequence as below.

UO₂²⁺ > Pb²⁺ > Cn²⁺ > Zn²⁺ > Ni²⁺ > Cd²⁺ > Co²⁺ > Ca²⁺ > Mg²⁺ > Sr²⁺ > Ba²⁺ > Na⁺