This paper describes the preparation, characterization and electroanalytical application of a composite consisting of titanium phosphate modified with nickel hexacyanoferrate. Titanium phosphate (TiPh) was formed from the reaction of titanium isopropoxide with H 3 PO 4 and deionized water. Next, the reaction of TiPh was performed with a metal ion (Ni +2 ) and potassium Hexacyanoferrate, designated as TiPhNIHCF. Spectroscopic techniques such as vibrational spectroscopy, X-ray diffraction (XRD), diffuse reflectance and cyclic voltammetry were used to characterize the TiPh and TiPhNiHCF. The graphite paste electrode containing TiPhNiHCF exhibited a redox couple with average potential (E  ') of 0.61V vs Ag/AgCl (KNO 3 1.0 mol L -1 ; v = 20 mV s -1 ) attributed to redox process Fe II (CN) 6 /Fe III (CN) 6 . The redox couple presents a sensitive response for determining dipyrone. The system showed a detection limit of 3.75 x 10 -4 mol L -1 and standard deviation of 1.8 % for n = 3, with an amperometric sensitivity of 34.84 mA / mol L -1 . The modified electrode was electrochemically stable and showed good reproducibility.www.ccsenet.org/ijc

This paper describes the preparation of a nanostructured silsesquioxane, the cloropropilsilsesquioxano (S) that was organofunctionalised with the 4-amino-5-4(pyridyl)-4H-1,2,4-triazole-3-thiol (APTT), the material obtained of the functionalization was described as SA. The material SA was characterized by spectroscopy in the region of infrared (FTIR). After proper characterization, were carried studies on adsorption of metallic ions such as Cu 2+ , Ni 2+ and Cd 2+ in the active sites of SA. Different methods were studied in the adsorption of metal ions above: aqueous, ethanol 42% and ethanol 99%, determining the adsorption equilibrium time, which for both means and metals the maximum time averaged 35 minutes. After determining the adsorption equilibrium time of metal ions in each system, we determined the specific sorption capacity (Nf max ) through adsorption isotherms. The results suggest that the sorption of metal ions on DPPIPS occurs mainly by surface complexation and a Langmuir model allowed describing the sorption of the metal ions on SA. The excellent adsorptive capacity made possible the development of a method for determination of metal ions at trace level in real samples such as waste water, ethanol fuel and alcoholics beverages.

The present work describes the preparation of nanoparticles of copper pentacyanonitrosyl complexes starting from the compound sodium nitroprusside. Copper pentacyanonitrosylferrate (NCuNP) nanoparticles were successfully synthesized by using deionized water and formamide as solvent. The material was characterized by Fourier-transforming infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and cyclic voltammetry (CV). The results revealed that the electronic spectra of NCuNP exhibited a broad intervalence charge transfer band at 685 nm. An XRD peak broadening pattern of the NCuNP was verified, indicating a particle decrease when formamide is used. The particle size of NCuNP is estimated to be 80 nm. The cyclic voltammogram of the modified graphite paste electrode with NCuNP showed two redox pairs with formal potentialsEθ′=0.36 V andEθ′=0.78 V (ν=20 mV s−1; KCl 1.0 M), attributed to the redox processCuI/CuIIand [FeII(CN)5NO]/[FeIII(CN)5NO], respectively. The graphite paste electrode with NCuNP presents electrocatalytic response for Sulfite determination.

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The octakis(3-chloropropyl)silsesquioxane (SS) was organofunctionalized with 4-amino-5-4(pyridyl)-4H-1,2,4-triazole-3-thiol. The product formed (SA) was undergo another reactions in two steps, first with copper and so hexacyanoferrate (III) to form CuHSA. The organofunctionalized silsesquioxane was characterized by the following techniques: scanning electron microscopy (SEM), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) in solid state, and thermogravimetric analysis in air and nitrogen atmosphere. The composite CuHSA was incorporated into a graphite paste electrode and the electrochemical behavior studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with CuHSA showed one redox couple with formal potentialEθ′=0.75 V versus Ag/AgCl(sat)(KCl 1.0 mol L−1;v= 20 mV s−1) attributed to the redox process Fe(II)(CN)6/Fe(III)(CN)6of the binuclear complex formed. The redox couple presents an electrocatalytic response of sulfhydryl compounds such as n-acetylcysteine and l-cysteine. For determination of n-acetylcysteine and l-cysteine the modified graphite paste electrode showed a linear region in the concentration range of 2 to 20 mmol L−1. The modified electrode was chemically and electrochemically stable and showed good reproducibility.