Preconcentration and differential pulse voltammetry of butylated hydroxyanisole at a carbon paste electrode

✍ Scribed by Joseph Wang; Bassama A. Freiha

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 538 KB
• Volume: 154
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(83)80009-9

✦ Synopsis

Butylated hydroxyamsole (BHA) and other tocopherols are shown to accumulate very strongly onto carbon paste, with the surface species retaining their characteristic electroactivlty. This accumulation serves as a preconcentration step which improves the voltammetric measurement with respect to the sensitivity and selectivity. After 5-mm preconcentration, a detection limit near 2 x lo-@ M BHA is obtained. Enhanced selectivity LS achieved if the electrode is transferred into an electrolytic blank solution between the preconcentration and measurement steps. The accumulated analyte can then be quantified m the presence of a 103-fold amount of a solution species with similar redox potential. The differential pulse stripping response is evaluated with respect to concentration dependence, reproducibility, preconcentration period, detection limit, and other variables. The preconcentratlon/medium exchange approach is exploited for selective detection of BHA in a flow mJection system. Applicability to various real samples is illustrated.