Collect. Czech. Chem. Commun.
2011, 76, 383-397
https://doi.org/10.1135/cccc2011011
Published online 2011-04-05 08:52:58
Determination of chloramphenicol by differential pulse voltammetry at carbon paste electrodes – The use of sodium sulfite for removal of oxygen from electrode surface
Ferenc T. Pastora, Hana Dejmkováb, Jiří Zimab and Jiří Barekb,*
a Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade
b Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry, 128 43 Prague 2, Czech Republic
Abstract
The possibility of determination of chloramphenicol by differential pulse voltammetry at four different carbon paste electrodes, in the full pH range (2–12) of Britton–Robinson (BR) buffer was investigated. Electrodes were prepared by mixing spectroscopic graphite powder or glassy carbon microbeads with mineral oil (Nujol) or tricresyl phosphate. Under optimal conditions (BR buffer pH 12, the electrode prepared from glassy carbon microbeads and tricresyl phosphate), linear calibration graph was obtained only in 10–5 M chloramphenicol concentration range. Determination of lower concentrations of chloramphenicol was complicated by irreproducible peak of oxygen from the carbon paste which overlapped with peak of chloramphenicol. Addition of sodium sulfite removed the oxygen peak without influence on the peak of chloramphenicol. Under optimal conditions (electrode paste made from glassy carbon microbeads, BR buffer pH 10 and 0.5 M sodium sulfite), straight calibration line was obtained in the 10–6 and 10–5 M chloramphenicol concentration range. Limit of determination was 5 × 10–7 mol/l.
Keywords: Chloramphenicol; Carbon paste electrodes; Oxygen peak; Oxygen removal; Sodium sulfite; Differential pulse voltammetry.
References: 23 live references.
