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Method validation in quantitative electrochemical analysis of colchicine using glassy carbon electrode

100%

Bodoki E., Săndulescu R., Roman L.

Open Chemistry

2007

vol. 5

issue 3

766-778

A cathodic differential pulse voltammetric determination of colchicine was validated using a glassy carbon electrode in HClO4/H3PO4 0.01 M. Colchicine gives an irreversible, diffusion-controlled peak at −862 mV vs. Ag/AgCl reference electrode. The cathodic peak is strongly influenced by a more alkaline environment with a shift towards more negative potentials. Method optimization was carried out in parallel for three types of electrodes (glassy carbon, mercury film and bismuth film coated glassy carbon). The cathodic peak current is higher using film-coated electrodes, but shows poorer intra-day reproducibility and a longer analysis time due to film renewal. Thus, a bare glassy carbon electrode was used to determine colchicine in the concentration range of 2.4 − 50 μg mL−1 (R 2 = 0.9998, n = 5), with a calculated detection limit of 0.80 μg mL−1. The proposed method was characterized according to ICH Harmonized Tripartite Guidance Q2(R1) by validation parameters (selectivity, linearity, accuracy, fidelity, limit of detection, limit of quantification) and it was successfully applied for the determination of colchicine from tablets, without the interference of the excipients. The method’s performances were evaluated and compared with both a known polarographic method and the official quantitative spectrophotometric determination from the Romanian Pharmacopoeia, Xth edition, respectively. [...]

Screen-printed electrodes modified with HRP-zirconium alcoxide film for the development of a biosensor for acetaminophen detection

88%

Sima V., Cristea C., Bodoki E., Duţu G., Sāndulescu R.

Open Chemistry

2010

vol. 8

issue 5

1034-1040

The development of a biosensor based on the immobilization of horseradish peroxidase (HRP) within a zirconium alkoxide-polyetilenimine film onto screen-printed electrodes (SPE) for acetaminophen detection and acetaminophen quantification in pharmaceutical products is described. The biosensor operation mode is based on monitoring the amperometric signal produced by the electrochemical reduction of the enzymatically generated electroactive oxidized species of acetaminophen in the presence of hydrogen peroxide. The enzyme immobilization is performed by retention in a polyethylenimine-zirconium alcoxide porous gel film, a technique that offers good entrapping and a protective environment for the biocomponent due to the hydration properties of the immobilization layer. SPEs have the advantage of being easily mass-produced at low costs with superior characteristics in comparison with classical electrode materials. In this configuration, zirconium alkoxide demonstrates its electrocatalytic activity. The biosensor allows the quantification of acetaminophen with a limit of detection of 6.21×10−8 M and a linear range between 4.35×10−7 M and 4.98×10−6 M. Finally, the biosensor is applied to the quantitative analysis of acetaminophen in Perdolan® tablets. [...]

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2 Open Chemistry

1 2010

1 2007

2 Bodoki E.

1 Cristea C.

1 Duţu G.

1 Roman L.

1 Sima V.

1 Sāndulescu R.

1 Săndulescu R.

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Method validation in quantitative electrochemical analysis of colchicine using glassy carbon electrode

Screen-printed electrodes modified with HRP-zirconium alcoxide film for the development of a biosensor for acetaminophen detection