In this study, a simple and rapid analytical method
development for ascorbic acid (AA) determination in
food samples by using differential pulse voltammetry
(DPV) method on ZnO/CNTs nanocomposite ionic liquid
modified carbon paste electrode. For this, several parameters,
such as ZnO/CNTs nanocomposite, ionic liquid ratio,
and pH, have been studied. The cyclic voltammogram
showed an irreversible oxidation peak at 0.61 V (vs.
Ag/AgCl
), which corresponded to the oxidation of AA.
Compared to common carbon paste electrode, the electrochemical
response was greatly improved. Under the optimized
conditions, the oxidation peak current of AA showed
linear dynamic range 0.1–450 μmol l
sat
−1
with a detection
limit of 0.07 μmol l
−1
, using the DPV method. The proposed
sensor was successfully applied to the determination
of AA in fresh vegetable juice, fruit juices and food supplement
samples without previous preparation and was compared
with a published electrochemical method.
