The effect of lipophilic anionic additives on detection limits of ion-selective electrodes based on ionophores with phosphoryl complexing groups

The dependence of detection limits of ion-selective electrodes (ISEs) based on ionophores with phosphoryl-containing terminal groups on the nature and concentration of lipophilic anionic compounds was investigated. It was sho wn that by including superstoichiometric amounts of lipophilic anionic comp ounds into the membrane, the lower detection limit can be decreased signifi cantly. A model describing the mechanism of the dependence of the lower det ection limits on both the amount and nature of the lipophilic anionic addit ives used is presented. (C) 2001 Published by Elsevier Science B.V.