An analytical application of the electrocatalysis of the iodate reduction at tungsten oxide films.
Talanta
; 69(1): 148-53, 2006 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-18970546
Films of non-stoichiometric tungsten oxides have been deposited onto glassy carbon surfaces by electrodeposition from acidic W(VI) solutions and the chemical stability of these oxides was investigated by using the electrochemical quartz crystal microbalance. At these modified surfaces, rotating disc electrode voltammetric experiments indicated that iodate is electrocatalytically reduced in a mass-transport controlled process. The influence of the film thickness on the response to iodate was investigated and the results indicated a linear relationship between catalytic current and film thickness for relatively thin oxide layers. The modified electrode was employed successfully as an amperometric sensor for iodate in a flow injection apparatus. The linear response of the developed method is extended from 5 micromol L(-1) to 5 mmol L(-1) iodate with a limit of detection (signal-to-noise=3) of 1.2 micromol L(-1). The repeatability of the method for 41 injections of a 1 mmol L(-1) iodate solution was 0.8% and the throughput was determined as 123 h(-1). Interference from other oxidant anions such as nitrate and nitrite was not noticeable, whereas bromate and chlorate interfere at slight levels. The method was used in the determination of the iodate content in table salt samples.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Talanta
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda