Table 1.

FIM selectivity coefficients, $K_{\mathrm{K},J}^{\text{pot}}$, for PPh₄⁺, Na⁺, Li⁺, NH₄⁺, and Cs⁺ relative to K⁺ for ionophore-doped membranes with a 71 or 33 mol % site ratio as well as for ionophore-free ion exchanger membranes.

	$\text{log }{K}_{\mathrm{K},J}^{\text{pot}}$ (71% site ratio)	$\text{log }{K}_{\mathrm{K},J}^{\text{pot}}$ (33% site ratio)	$\text{log }{K}_{\mathrm{K},J}^{\text{pot}}$ (no ionophore)a
PPh4+	+8.0	+2.4	+17.1
Li+	−4.8	−4.6	−1.4
Na+	−2.4	−2.1	−1.0
NH4+	−2.5	−0.7	+0.6
Cs+	−2.9	+1.3	+2.5

^aCalculated from ref. 35