Use of modified NaY zeolite as ionophore for perchlorate selective electrode

Abstract

NaY zeolite is well deserved for being employed as a catalyst, adsorbent, and ion exchanger. Therefore, its ion exchange property is used in ion selective electrodes (ISEs). Commercial NaY zeolite was modified with cetyltrimethylammonium bromide (CTAB) in various concentrations (100, 150, and 200 mM), denoted them as 100, 150 and 200 SMZ, respectively. XRD, FT-IR, SEM and TGA/DTG showed good agreement of CTAB adsorption on zeolite surface. Then SMZ is used to fabricate polymeric membrane with polyvinyl chloride (PVC) plasticized with o-nitrophenyl octyl ether (o-NPOE). The best performance of ISE was exhibited at the membrane composition of 200 SMZ: PVC: NPOE in the ratio of 16.30: 30.03: 62.07. The selectivity coefficients of the proposed electrode towards various interfering ions were determined by separate solution method (SSM) and the result showed that our fabricated ISE is selective to perchlorate anion. This electrode worked well over wide concentration range from 1 × 10-5 to 1 × 10-2 M of with a Nernstian slope of -57.63 ± 0.47 mV decade-1 with a low detection limit of 9.28 μM. The response time of electrode is very fast (≤ 10 s) over a period of 1 month with good reproducibility. The fabricated ClO4- ISEs were used to analyze ClO4- in real water samples with satisfactory results.