PEMBUATAN DAN KARAKTERISASI MEMBRAN ELEKTRODA SELEKTIF ION CD(II) BERBASIS PVC DENGAN NA2S SEBAGAI IONOFOR

Abstract

Preparation and characterization of Cd²⁺ ion selective electrode membrane using sodium sulfide (Na₂S) as an ionophore has been conducted. This research aims to create and characterize Cd²⁺ ion selective electrode membrane as a chemical sensors. Membrane of ion selective electrode was made with the optimum composition with ratio of Na₂S : PVC : DOP was 6 : 3 : 1. The membrane was doped using 1 M Cd²⁺ solution for 7 days, and characterized using FT-IR spectroscopy. FT-IR characterization used to determine the shift of wave number from absorption spectrum, the results showed the absorption 851 cm^-1 wave lenght is Cd–S bond. ion selective electrode Cd²⁺-Na₂S characterization show that ion selective electrode worked well with an internal solution composition 1:3 with the linear concentration range 1×10^-4 - 1×10^-1 M, with Nernst factor was 29.87 mV/decade and the limit of detection was 5.71×10^-5 M as a Cd(CH₃COO)₂ concentration or equivalent to Cd²⁺ concentration of 0.6422 ppm. Ion selective electrode worked optimally in the pH range 4-6, with the response time was 10-60 seconds and can be used up to 5 days. The presence of interfere ions such as Cu²⁺, Zn²⁺, Cl^-, NO₃^-, and SO₄^2- didn’t affect the performance of  ion selective electrode Cd²⁺-Na₂S determining Cd²⁺ ions in the samples.

Keywords: Cd(II), Ion selective Electrodes, PVC membrane, Na₂S.