Plasticizer for Liquid Polymeric Membrane of Ion Selective Electrode Based on Thiazole Derivatives as Ionophore

Abstract

Ion selective electrode (ISE) is an electrode that has been designed to identify heavy metal ion in a solution. In this experiment, thiazole-4-carboxamide (Th) is used as ionophore and sodium tetraphenylborate (NaTPB) as an additive. Polyvinyl chloride (PVC) was used as a polymeric matrix in the membrane selective electrode. Different type of commonly used plasticizers is analysed to choose the one with the best response. There are four types of plasticizer used; dioctyl phthalate (DOP), dibutyl phthalate (DBP), benzyl acetate (BA) and nitrobenzene (NB). The ratio (w/w)% used for all plasticizers Th:PVC:NaTPB:Plasticizer is 5.0:30.0:2.0:63.0. ISE is used in a sample solution with different concentration to figure out the best plasticizer. Ion selective membrane using BA gives the best response with 19.3±1.4 slope value, while ion selective membrane using DOP gives the least response with 11.3±0.7 slope value.