Determination of Na+, K+, Ca2+, and Cl- ions in wood pulp suspension usingion-selective electrodes

Ion-selective electrodes were optimized for the determination of Na+, K+ an d Ca2+ in wood pulp suspension. The electrodes were based on solvent polyme ric membranes (plasticized PVC) containing neutral carriers. The results ob tained with the optimized electrodes were compared to those obtained with c ommercially available ion-selective electrodes including glass electrode fo r Na+ and solvent polymeric membrane-based electrodes for K+, Ca2+ and Cl-. Additionally, commercially available glass electrodes for pH, as well as a solid-state membrane electrode for Cl- were used. The free ion concentrati on of pulp samples obtained by ion-selective electrodes was compared to the total concentrations obtained by ICP-AES and XRF.