Determination of arsenate in water by anion selective membrane electrode using polyurethane-silica gel fibrous anion exchanger composite

摘要

Polyurethane (PU)-silica (Si gel) based fibrous anion exchanger composites were prepared by solid-gel polymerization of polyurethane in the presence of different amounts of silica gel. The formation of PU-Si gel fibrous anion exchanger composite was characterized by Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA-DTA), scanning electron microscopy (SEM) and elemental analysis. The membrane having a composition of 5∶3 (PU∶Si gel) shows best results for water content, porosity, thickness and swelling. Our studies show that the present ion selective membrane electrode is selective for arsenic, having detection limit (1× 10~(-8) M to 1 × 10~(-1) M), response time (45 s) and working pH range (5-8). The selectivity coefficient values for interfering ions indicate good selectivity for arsenate (AsO_4~(3-)) over interfering anions. The accuracy of the detection limit results was compared by PCA-Arsenomat.