Electrochemical Determination of Catechol in Tea Amples Using Anthraquinone Modified Carbon Paste Electrode
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Date
2009-07
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Addis Ababa Universty
Abstract
The electrochemical behavior of catechol was investigated using square wave
voltammetry with anthraquinone modified CPE and was found to be very sensitive. The
modified electrodes showed an enhancement of current response for catechol as
compared to the unmodified carbon paste electrode. Two varieties of tea, namely Green
tea, and Wush Wush tea were investigated. Responses for the extracts using ethanol:
water mixture showed green tea to be superior in catechol content.
Optimization of different variables such as pH of working solution, modifier composition
and square wave parameters such as frequency, amplitude and step potential were made
to improve the method efficiency during the experiment. The reproducibility for the nine
repeated analysis of 80 μmolL-1 of catechol gave a relative standard deviation of 3.65%,
indicating excellent reproducibility of the method. Linear calibration plots were obtained
in the range 6 to 80 μmolL-1 with (R = 0.99853) and the detection limit with (S/N=3) was
as low as 2.155x10-7 molL-1
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Keywords
Catechol in Tea