Table 4.

Formal complex formation constants, log β, of Ag⁺ obtained for ionophores I–X in PVC membranes assuming a 1:1 stoichiometry of their complexes with Ag⁺ (S.D. for n = 3 unless indicated otherwise)

Ionophore	From selectivity data (o-NPOE)	Sandwich membrane technique (o-NPOE)	Ionophore	From selectivity data (o-NPOE)	Sandwich membrane technique (o-NPOE)	From optode responses (DOS)
I	5.86 ± 0.04	6.93 ± 0.05a	VI	6.41 ± 0.04
II	5.07 ± 0.04		VII	10.39 ± 0.08	9.93 ± 0.04
III	5.50 ± 0.03		VIII	12.14 ± 0.13	11.02 ± 0.07b 9.22± 0.04c	8.9 [31]
IV	3.30 ± 0.07		IX	10.85 ± 0.14	11.31 ± 0.10a	7.8
V	3.89 ± 0.07		X	11.00 ± 0.03	11.32 ± 0.17a	9.7

^an = 4.

^bn = 2.

^cDOS/PVC [31].