title: A novel salicylate-selective electrode based on a Sn(IV) complex of salicylal-imino acid Schiff base.
abstract: A novel poly(vinyl chloride) membrane electrode with high selectivity toward salicylate (Sal-), based on the use of the salicylal-imino acid Schiff base dibenyl complex of Sn(IV) [Sn(IV)-SIADBen] as ionophore is described. The influence of lipophilic charged additives on the performance of the electrode was studied. The results suggested that Sn(IV)-SIADBen according to a positively-charged carrier mechanism. The influence of several other variables was investigated in order to optimize the potentiometric response and selectivity of the electrode. The electrode based on Sn(IV)-SIADBen, with 30.44 wt% PVC, 64.55 wt% plasticizer [dioctyl phthalate (DOP)], 3.81 wt% ionophore, and 1.2 wt% anionic additive exhibited a linear response for the Sal- ion over the concentration range 1.0x10(-1) to 2.5x10(-6) mol l-1, and displayed an anti-Hofmeister selectivity sequence as follows: salicylate>>perchlorate>thiocyanate>benzoate>iodide>nitrate>chloride>nitrite approximately acetate>citrate>sulfate. UV-Visible absorption spectra were used to examine the specific interaction of salicylate with the ionophore. The electrode was applied to clinical medical analysis, and the results obtained were consistent with those obtained by conventional methods.
authors.affiliation: Institute of Analytical Chemistry, the College of Chemistry and Chemical Engineering, Southwest China Normal University, Chongqing 400715, People's Republic of China.
authors.forename: Lan
authors.initials: L
authors.lastname: Xu
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Chai
authors.forename: Xiu-Ling
authors.initials: XL
authors.lastname: Wang