Square-Wave Voltammetric Determination of Paracetamol and Codeine in Pharmaceutical and Human Body Fluid Samples Using a Cathodically Pretreated Boron-Doped Diamond Electrode

Anderson M Santos,Fernando C Vicentini,Romeu C Rocha-Filho,Orlando Fatibello-Filho,Patrícia B Deroco

doi:10.5935/0103-5053.20150203

Anderson M Santos, Fernando C Vicentini + Show 3 more

Open Access

https://doi.org/10.5935/0103-5053.20150203

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Abstract

Simple, fast, and inexpensive electroanalytical procedures were developed for the determination of codeine (COD) solely and paracetamol (PCT) and COD simultaneously in pharmaceutical formulations and human body fluids. The methods involve the combination of square-wave voltammetry (SWV) with a cathodically pretreated boron-doped diamond electrode and a 0.2 mol L –1 acetate buffer (pH 4.0) solution as the supporting electrolyte. Significantly low limits of detection were obtained for COD solely or PCT and COD simultaneously: 1.19 or 18 and 14 nmol L –1 , respectively. The proposed SWV method was successfully applied in the simultaneous determination of PCT and COD in four samples of pharmaceutical tablets, with results similar (at 98% confidence level) to those obtained using a reference high-performance liquid chromatography (HPLC) method. Additionally, adequate results were obtained when concentrations of PCT and COD were determined in human urine or serum samples by addition-recovery. Clearly, the proposed method is an excellent option for the determination of COD solely or PCT and COD simultaneously.

Highlights

After each pretreatment of the Boron-doped diamond (BDD) surface, the electroactive area of the working electrode was estimated by CV, using a 1.0 mmol L–1 [Fe(CN)6]4– solution in aqueous 0.10 mol L–1 KCl (Figures S1a and S1c in the Supplementary Information), based on the Randles-Sevcik equation:[30]
The corresponding estimated electroactive areas were 0.41 or 0.50 cm[2], for the anodically or cathodically pretreated BDD electrode, respectively. From these results it is clear that the attained electrochemical response for the [Fe(CN)6]4− probe is significantly affected by the type of electrochemical pretreatment applied on the BDD electrode surface
The cathodic pretreatment of the BDD electrode leads to a greater electroactive area than the anodic pretreatment, which is coherent with the fact that usually the kinetic behavior of the [Fe(CN)6]4−/3– redox couple is more reversible on cathodically than on anodically pretreated BDD electrodes.[13]

Summary

Introduction

The determination of drugs in pharmaceuticals and biological fluids is an important area of analytical chemistry that is undergoing rapid development and plays a significant role in quality control, diagnosis in clinical medicine (in cases of suspected drug intoxication), and studies of physiological function.[1,2] the development of simple, rapid, sensitive, and accurate analytical procedures for the identification and quantification of drugs is currently of great interest and significance. The simultaneous determination of PCT and COD in pharmaceutical formulations is necessary for industrial quality control and to ensure the correct dose in patients during treatment and in biological fluids for physiological pharmacokinetics and clinical diagnosis. In this work we report on the coupling of voltammetric techniques with the distinctive properties of a cathodically pretreated BDD electrode for the development of sensitive electroanalytical procedures for the determination of COD solely or of PCT and COD simultaneously in pharmaceutical formulations and in synthetic human biological fluids (urine and serum). The mobile phase was an acetonitrile-water mixture (75/25, v/v), used at a flow rate of 1 mL min−1, while the injection volume was 20 μL

Analytical procedure

Results and Discussion

Method

Conclusions