Electroanalytical studies on cadmium(II) selective potentiometric sensors based on t-butyl thiacalix[4]arene and thiacalix[4]arene in poly(vinyl chloride) |
| |
Authors: | Vinod K. Gupta Ajay K. Jain Gaurav Maheshwari |
| |
Affiliation: | a Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal, India b Institute for Inorganic and Analytical Chemistry, Freie Universitaet, Berlin 14195, Germany |
| |
Abstract: | Cd2+-selective sensors have been fabricated from poly(vinyl chloride) (PVC) matrix membranes containing t-butyl thiacalix[4]arene (I) and thiacalix[4]arene (II) as electroactive materials. The addition of sodium tetraphenylborate and the plasticizer 2-nitrophenyl octyl ether has been found to improve the performance of the sensors substantially. The membranes of various compositions of the two thiacalixarenes have been investigated and it was found that the best performance was obtained for the membrane of composition II:PVC:NaTPB:NPOE in the ratio 5:120:3:150. The sensor shows a linear potential response for Cd2+ over a wide activity range 3.2 × 10−6 to 1.0 × 10−1 M with Nernstian compliance (29.5 mV decade−1 of activity) in pH range 4.5-6.5 and a fast response time of ∼8 s. The potentiometric selectivity coefficient values determined by matched potential method indicate excellent selectivity for Cd2+ ions over mono-, di- and trivalent interfering cations. The sensor exhibits adequate shelf life (∼3 months) with good reproducibility (S.D. ±0.2 mV) and can also be used in partially non-aqueous media having up to 20% (v/v) methanol, ethanol or acetone content with no significant change in the value of slope or working activity range. The sensor has been used in the potentiometric titration of Cd2+ with EDTA. The sensor could be successfully used for the quantification of cadmium in river water samples. |
| |
Keywords: | Poly(vinyl chloride) t-Butyl thiacalix[4]arene Thiacalix[4]arene Cadmium selective sensor Nernstain slope |
本文献已被 ScienceDirect 等数据库收录! |