Coated-wire Lithium lon-selective Electrodes Based on Polyal koxylate Complexes

Abstract

Barium and lithium adducts of polyalkoxylates have been investigated as sensors in lithium ion-selective electrodes using a microconduit flow injection analysis system. Dioctyl phenylphosphonate (DOPP) and dioctyl 3-nitrophenylphosphonate (N-DOPP) were employed as solvent mediators. Selectivity coefficients, kf?'~, r the Ba(PPG 1025)0.s9. PB)2 DOPP-based lithium electrode in 0.14 M sodium chloride solution are as follows: Na+ 3.7 x 10-2, K+ 4.4 x 10-3, Ca2+ 4.1 x 10-1 and Mg2+ 8.0 x 10-2. The selectivity coefficients are compared with those for two other previously reported lithium electrodes. The barium polyalkoxylate adduct is a better sensor for lithium than its lithium analogue