Silver Selective Electrode Based on Hybrid Mesoporous Silica (MCM‐41) Modified Material

Abstract

A silver selective electrode based on TEPQA‐MCM‐41 material was developed and used for the selective determination of Ag+ ion in various samples. The effect of various plasticizers i. e. dimethyl phthalate (DMP), Tris(ethylhexyl)phosphate (TEP), bis‐(2‐ethylhexyl)sebacate (BEHS), bis‐(2‐ethylhexyl)adipate (BEHA) was investigated. The electrode of the composition of 2 : 1 : 77 : 12 : 8 (w/w, %) of TEPQA‐MCM‐41 : NaTPB : Graphite powder : paraffin oil : DMP respectively, works satisfactorily in a wide concentration range of 1.3×10−9 M–1.0×10−1 M for Ag+ ion with a lower detection limit (LOD) of 1.0×10−9 M and has Nernstian slope of 63.4± 1 mV/decay. The electrode can be used in a pH range of 2.3 to 6.7 for a period of 3 months without any divergence in potential response. The selectivity coefficient calculated by fixed interference method indicates the high selectivity of the electrode towards Ag+ ion over other tested cations.

Potentiometric Sensing

“…The electrode was tested in spiked sea/river/tap water samples. Mesoporous silica material modified 3-(triethoxysilyl) propyl-2-(quinoxalin-2-ylamino)­acetamide as an ionophore was used by Singh et al to prepare another carbon paste Ag + -selective electrode . The proposed sensor allows one to detect 1 nM Ag + ions with a sensitivity of 63.4 mV/decade in the pH range from 2.3 to 6.7.…”

“…Mesoporous silica material modified 3-(triethoxysilyl) propyl-2-(quinoxalin-2-ylamino)acetamide as an ionophore was used by Singh et al to prepare another carbon paste Ag + -selective electrode. 140 The proposed sensor allows one to detect 1 nM Ag + ions with a sensitivity of 63.4 mV/decade in the pH range from 2.3 to 6.7. The complex formation constants with a number of cations were determined using a sandwich membrane method, giving the highest value of 10 6.4 for the Ag + ion.…”