Voltammetric studies of titanium (IV) phosphate modified with copper hexacyanoferrate and electroanalytical determination of N-acetylcysteine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Processo FAPESP: 03/12882-6

Processo FAPESP: 07/57678-8

Titanium (IV) Phosphate copper hexacyanoferrate composite (TiPhCuHCF) was prepared using a new methodology for the synthesis. A preliminary characterization of the precursor and resulting materials was defined using spectroscopic and chemical techniques. The cyclic voltammogram of the modified electrode containing TiPhCuHCF exhibited two redox couples. The first and second redox couples present a formal potential (E(theta')) of 0.18 and 0.76 V and were ascribed to the Cu(+/)Cu(2+) (E(theta'))(1) and Fe(2+)(CN)(6)/Fe(3+)(CN)(6) (E(theta'))(2) processes, respectively. In a preliminary study, the peak located at 0.76 V displays a sensitive response to N-acetylcysteine. The modified graphite paste electrode showed a linear range from 1.0 x 10(-5) to 7.0 x 10(-4) mol L(-1) for the determination of N-acetylcysteine with a limit detection of 6.96 x 10(-5) mol L(-1) and relative standard deviation of +/- 5% (n = 3) and amperometric sensitivity of 24.79 x 10(-3) A mol L(-1). The modified electrode was electrochemically stable and showed good reproducibility.