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conferenceseries
.com
Volume 7
Biosensors Journal
ISSN: 2090-4967
Electrochemistry 2018
June 11-12, 2018
June 11-12, 2018 | Rome, Italy
4
th
International Conference on
Electrochemistry
Electrochemical determination of caffeine content in Ethiopian coffee samples using lignin modified
glassy carbon electrode
Meareg Amare
and
Senait Aklog
Bahir Dar University, Ethiopia
L
ignin film was deposited at the surface of glassy carbon electrode potentiostatically. In contrast to the unmodified glassy
carbon electrode, an oxidative peak with an improved current and overpotential for caffeine at modified electrode showed
catalytic activity of the modifier towards oxidation of caffeine. Linear dependence of peak current on caffeine concentration in
the range 6×10
−6
to 100×10
−6
molL
−1
with determination coefficient and method detection limit (LoD=3 s/slope) of 0.99925 and
8.37×10
−7
molL
−1
, respectively, supplemented by recovery results of 93.79–102.17% validated the developedmethod. An attempt
was made to determine the caffeine content of aqueous coffee extracts of Ethiopian coffees grown in four coffee cultivating
localities (Wonbera, Wollega, Finote Selam, and Zegie) and hence to evaluate the correlation between users preference and
caffeine content. In agreement with reported works, caffeine contents (w/w%) of 0.164 in Wonbera coffee; 0.134 in Wollega
coffee; 0.097 in Finote Selam coffee; and 0.089 in Zegie coffee were detected confirming the applicability of the developed
method for determination of caffeine in a complex matrix environment. The result indicated that users’ highest preference for
Wonbera and least preference for Zegie cultivated coffees are in agreement with the caffeine content.
senaitaklog16@gmail.comBiosens J 2018, Volume 7
DOI: 10.4172/2090-4967-C1-003