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Bismuth and Bismuth-Chitosan modified electrodes for determination of two synthetic food colorants by net analyte signal standard addition method

100%

Asadpour-Zeynali K., Mollarasouli F.

issue 6

711-718

In this paper, an electrochemical application of bismuth film modified glassy carbon electrode for azo-colorants determination was investigated. Bismuth-film electrode (BiFE) was prepared by ex-situ depositing of bismuth onto glassy carbon electrode. The plating potential was −0.78 V (vs. SCE) in a solution of 0.15 mg mL−1 Bi(III) and 0.05 mg mL−1 KBr for 180 s. In the next step, a thin film of chitosan was deposited on the surface of bismuth modified glassy carbon electrode, thus the bismuth-chitosan thin film modified glassy carbon electrode (Bi-CHIT/GCE) was fabricated and compared with bare GCE and bismuth modified GCE. Azo-colorants such as Sunset Yellow and Carmoisine were determined on these electrodes by differential pulse voltammetry. Due to overlapping peaks of Sunset Yellow and Carmoisine, simultaneous determination of them is not possible, so net analyte signal standard addition method (NASSAM) was used for this determination. The results showed that coated chitosan can enhance the bismuth film sensitivity, improve the mechanical stability without caused contamination of surface electrode. The Bi-CHIT/GC electrode behaved linearly to Sunset Yellow and Carmoisine in the concentration range of 5×10−6 to 2.38×10−4 M and 1×10−6 to 0.41×10−4 M with a detection limit of 10 µM (4.52 µg mL−1) and 10 µM (5.47 µg mL−1), respectively

Carbon ceramic electrode incorporated with zeolite ZSM-5 for determination of Piroxicam

81%

Asadpour-Zeynali K., Majidi M., Zarifi M.

Open Chemistry

2010

vol. 8

issue 1

155-162

A new chemically modified electrode is constructed based on carbon ceramic electrode incorporated with zeolite ZSM-5. Voltammetric behavior of piroxicam at the carbon ceramic zeolite modified electrode (CCZME) was investigated. The modified electrode exhibited catalytic activity toward the electrooxidation of piroxicam. Experimental parameters such as solution pH, scan rate, concentration of piroxicam and zeolite amount were studied. It has been shown that using the CCZME, piroxicam can be determined by differential pulse voltammetry (DPV) and hydrodynamic amperometry (HA). Under the optimized conditions the calibration plots are linear in the concentration ranges of 0.20–25.00 and 0.20–50.10 μM with limit of detections of 0.65 and 0.29 μM for DPV and HA, respectively. The modified electrode with DPV and HA methods was successfully applied for analysis of piroxicam in pharmaceutical formulations. The results were favorably compared to those obtained by the spiked method. The results of the analysis suggest that the proposed method has promise for the routine determination of piroxicam in the products examined. [...]

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2 Open Chemistry

1 2014

1 2010

2 Asadpour-Zeynali K.

1 Majidi M.

1 Mollarasouli F.

1 Zarifi M.

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Bismuth and Bismuth-Chitosan modified electrodes for determination of two synthetic food colorants by net analyte signal standard addition method

Carbon ceramic electrode incorporated with zeolite ZSM-5 for determination of Piroxicam