Development of a Novel Square Wave Voltammetric Method for Determination of Phenoxymethylpenicillin and Benzylpenicillin in Animal Products and Pharmaceutical Samples

Abstract

Penicillins have been used widely in humans and animal husbandry to control and manage bacterial infections due to their strong antibacterial activity. However, pressence of penicillin residues in animal products has raised health concerns. The existing detection methods, such as HPLC and enzymatic methods are labour intensive and expensive. There is therefore, a need to develop a simple, more sensitive and field deployable diagnostic tool to determine penicillins levels in animal products. This research work reports development of a simple square voltammetric method for detection of phenoxymethylpenicillin (penicillin V) and benzylpenicillin (penicillin G) using a surfactant modified support electrolyte, ABS-SDS (acetate buffer solution-sodium dodecyl sulfate) on glassy carbon electrode (GCE). The surfactant enhanced the voltammetric current response for penicillin V and penicillin G for about ten and five times respectively with no significant change in the oxidation potential of these two drugs. The optimal pH and SDS concentration were found to be pH 4.5 and 0.347M respectively. The diffusion coefficients for penicillin G were estimated to be 6.01x10-7 cm2/sec and 1.39x10-6 cm2/sec in absence and in presence of SDS respectively at optimum conditions in acetate buffer solution. The limit of detection for penicillin G in this method was 2.5×103ng/L against a maximum residue limit (MRL) of 4×103ng/L set by the European Union. Foreign substance did not interfere with detection of both penicillin V and penicillin G. This implies that the developed method is sensitive enough for use in the analysis of penicillin G and V in diverse samples.