Electrocatalytic and flow-injection determination of the antioxidant tert.-butylhydroxyanisole at a nickel phthalocyanine polymer modified electrode

✍ Scribed by M.A. Ruiz; M.G. Blázquez; J.M. Pingarrón

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 687 KB
• Volume: 305
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)00340-r

✦ Synopsis

The behaviour of a nickel phthalocyanine polymer-coated glassy carbon electrode has been investigated in order to test it as an amperometric detector in flow systems. The oxidation process of the antioxidant terf.-butylhydroxyanisole (BHA) has been studied for this purpose. The monomer Ni(II)-4,9,16,23-tetraaminophthalocyanine was synthesized and characterized. Electropolymerization was accomplished by repetitive cycling between -0.2 and +0.9 V in a dimethyl sulfoxide solution of the monomer. The characteristics of the BHA oxidation process at the polymeric modified electrode were examined by linear sweep voltammetry. A flow-injection method with amperometric detection based on this oxidation process has been developed. At an applied potential of 0.70 V, calibration graphs were linear within the range lo-O.01 mg l-' BHA with a limit of detection of 2.7 pg 1-l BHA (1.5 X low8 mol 1-l). Interferences from BHT (tert.-butylhydroxytoluene), TBHQ (tert.-butylhydroquinone), propyl gallate, ascorbic acid, sodium bisulfite and citric acid were tested. The method was applied to the determination of BHA in biscuits samples