dc.description.abstract |
Cyclic voltammetric and electrochemical impedance spectroscopic results showed
potentiodynamic deposition of a noble poly(aquachlorobis(1,10-
phenanthroline)cupper(II)iodidemonohydrate) (poly(ACP2CuIH)) polymer film on the
surface of glassy carbon electrode. In contrast to the unmodified glassy carbon electrode,
poly(ACP2CuIH) film modified glassy carbon electrode (poly(ACP2CuIH)/GCE) in a solution
containing equi molar mixture of theophylline and caffeine revealed well separated oxidative
peaks with much enhanced peak current and reduced over-potential showing the
electrocatalytic property of the polymer film towards the oxidation of theophylline and
caffeine. Poly(ACP2CuIH)/GCE was used for square wave voltammetric simultaneous
determination of theophylline and caffeine in various real samples including pharmaceutical
tablets, tea, and human serum samples. Under optimized solution and square wave
voltammetric parameters, oxidative peak current response of poly(ACP2CuIH)/GCE showed
a linear dependence on the concentration of caffeine and theophylline in a reasonably wide
range of concentration. The method showed exactly the similar sensitivity towards
simultaneous theophylline and caffeine as does for their separate detection. The current
response of poly(ACP2CuIH/GCE for simultaneous detection of theophylline and caffeine
showed a linear dependence on the respective concentration in the range of 1–200.0 μM with
a limit of detection of 8.92 × 10-9
M for theophylline, and 1.02 ×10-8 M for caffeine. The
method was successfully used to detect theophylline and caffeine in tea (Black lion, Addis,
and Wush wush), pharmaceutical tablet (Panadol extra and Theodrine), and human blood
serum real samples with excellent recovery results of 97.0–102.0% and 95.4–96.8%, 99.0–
101.0 and 98.9–100.0, and 100.0–101.4% and 98.9–99.3%, respectively. The accuracy,
selectivity, stability, and reproducibility results validated the developed method for its
applicability for simultaneous determination of theophylline and caffeine in complex matrix
real samples including tablet formulation, tea, and human blood serum samples |
en_US |