C14-K22B5 is the best magnesium selective ionophore. The PVC membrane stability is improved by this ionophore’s high lipophilicity due totetraoctadecane and adamantyl groups. C14-K22B5 has a linear response between 1×10-5 M and 0.1 M magnesium ion.
1. K. Suzuki, et al., Design and Synthesis of Calcium and Magnesium Ionophores Based on Double-Armed Diazacrown Ether Compounds and Their Application to an Ion-Sensing Component for an Ion-Selective Electrode. Anal Chem. 1995;67:324-334.