Potentiometric studies on neutral carrier based ion selective electrodes for aluminium ions : effect of CNTs in the liquid membrane electrode

Abstract

Potentiometric chemical sensors for aluminium ion based on T4, T5, T6 as neutral ionophores has been prepared. o-Nitrophenyl octyle ether (o-NPOE) was used as plasticiser and sodium tetraphenyl borate (NaTPB) was used as lipophilic additive for the preparation of membranes. These electrodes have been studied for the detection of aluminium ions in different concentration range of 10-5 to 10-1. The electrodes have been studied for interference from metal ions other than aluminium by using fixed interference method. The electrode show reasonably good selectivity for aluminium ions in the presence of interfering ions like Fe3+, Cr3+, Tb3+, Sm3+, La3+, Ce3+, Co2+, Zn2+, Cu2+, Mg2+ and Ca2+. The proposed electrodes also showed stable behaviour in different pH ranges. The membranes containing T4, T5, T6 as ionophores doped with CNTs and these electrodes were also studied for detection limits, interference studies and in different pH ranges. Performance of the electrodes containing CNTs was better than other electrodes, not containing CNTs. Overall performance of all the electrodes was very good and stable for aluminium ions.