title: Zeolite encapsulated Ni(II)-Schiff-base complex: a novel size-selective electro-catalyst for the determination of the purity of stevioside.
abstract: Ship-in-a-bottle complex of nickel(II) containing the ligand N,N'-bis(2,4-dihydroxyacetophenone)-2,2-dimethylpropandiimine (H2{salnptn(4-OH)2}) has been synthesized in zeolite Y. The characteristics of the encapsulated complex are identified by the methods of EDX, SEM, XRD, FT-IR and cyclic voltammetry. A catalytic effect in the electrochemical oxidation of glucose, fructose and sucrose, and a blocking effect in stevioside oxidation are demonstrated on the Ni(II){salnptn(4-OH)2}-Y/CPE. The effects of some parameters, such as potential scan rate and concentration of carbohydrates are investigated. The rate constants for the catalytic reaction (k') of carbohydrates are also obtained. The size-selective electro-catalyst shows a good linear dependency on carbohydrates' concentration in the range of 0.01-0.06 M with the detection limit of 6.4mM at the signal-to-noise ratio of 3. Furthermore, the modified electrode exhibits no interference with the simultaneous presence of stevioside. In brief, these results demonstrate that Ni(II){salnptn(4-OH)2}-Y composites have a great potential for synthesizing size-selective electrocatalysts for determining the purity of stevioside.
authors.affiliation: Department of Chemistry, K.N. Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran.
authors.forename: Mehdi Rashvand
authors.initials: MR
authors.lastname: Avei
authors.forename: Majid
authors.initials: M
authors.lastname: Jafarian
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Etezadi
authors.forename: Fereydoon
authors.initials: F
authors.lastname: Gobal
authors.forename: Maryam
authors.initials: M
authors.lastname: Khakali
authors.forename: Saeed
authors.initials: S
authors.lastname: Rayati
authors.forename: Mohammad Ghasem
authors.initials: MG
authors.lastname: Mahjani
mesh_terms: D002241:Carbohydrates / Q000032:analysis*; D002384:Catalysis; D045786:Diterpenes, Kaurane / Q000737:chemistry*; D004566:Electrodes; D005960:Glucosides / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D033362:Powder Diffraction; D012545:Schiff Bases / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D017641:Zeolites / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D045786:Diterpenes, Kaurane; D005960:Glucosides; D012545:Schiff Bases; C012043:stevioside; D017641:Zeolites; D009532:Nickel