“…The first neutral-carrier based lead ion selective electrodes were based on oxa- or dioxadicarboxylic acid diamides, ,,, giving nearly Nernstian responses to PbA + (A - = Cl - , OH - , OAc - , or NO 3 - ). Selectivity coefficients for different lead species were calculated from the emf responses at different pH values ( Pb 2+ -1 (ETH 322), log
(FIM): 672 PbCl + , −1.8; PbNO 3 + , −1.8; PbOAc + , −1; Pb 2+ , −4.8; H + , −4.2; log
(SSM): Li + , −2.9; Ca 2+ , −5.2; Cu 2+ ; −5.0; Cd 2+ ; −3.7; Ba 2+ , −4.7; BBPA; note the similarity of this ionophore to Cd 2+ -1 ).…”