No abstract

The construction and performance characteristics of a novel Iron(III) membrane sensor based on (37-bis-[(diethoxy-thiophosphoryl)-oxy]-5,11,17,23,29,35-hexa-kis-(1,1-dimethylethyl)-calix[6]arene-38,39,40,41,42-pentol) (A) were reported in this paper. The sensor was prepared by incorporating compound (A) into a plasticized polyvinyl chloride PVC membrane. The electrode reveals a Nernstian behavior over a wide iron ion concentration range (1.0 × 10 −2-1.0 × 10 −4 mol•L −1), and relatively low detection limit (1.0 × 10 −5 mol•L −1). The potentiometric response was independent on the pH of the solution in the range of 4-7. The electrode showed a very short response time (<5 s). It exhibited very good selectivity relative to a wide variety of metal cations. Correlation of selectivity coefficient values with ionic radii of interferent cations was discussed. The proposed iron-ISE was applied for analysis of iron containing samples with comparison to a recommended spectrophotometric method.