Voltammetric determination of the antioxidant tert‐butylhydroxytoluene (BHT) at a carbon paste electrode modified with nickel phthalocyanine
1994; Wiley; Volume: 6; Issue: 5-6 Linguagem: Inglês
10.1002/elan.1140060519
ISSN1521-4109
AutoresM.A. Ruiz, Paloma áńez‐Sedeń, José M. Pingarrón,
Tópico(s)Analytical Chemistry and Sensors
ResumoAbstract The voltammetric behaviar of the antioxidant tert–butyltydroxytoluene (BHT) at a carbon paste electrode modified with nickel phthalocyanine is described, and method for the determination of this antioxidant based on its oxidations at the modified electrode it proposed. Cyclic voltammograms showed a well defined oxidations peak for BHT at potentials approximately. 200 mV lower than the poorly defined peck obtained in the absence of the electocatalyst. A 35%, methanol :water medium, a modifier concentrations of 2%, and pH 2 were chosen as working conditions. Results obtained suggest that the oxidation signal arisen as a result of BHT chemically reducing Ni(II)to Ni(I) in the phthalocyanine, and the subsequent electrochemical oxidations of the latter. Using differential pulse voltammetry at Δ E =50 mV, a linear calibration range was obtained between 1 and 50 mg L −1 BHT with a detection limit of 0.17 mg L −1 BHT interferences from other substances commonly present in commercial antioxidant mixtures were tested. The developed method was applied to the determinations of BHT in stabilized diethyl ether.
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