Boron-doped diamond electrochemical sensor for sensitive determination of nicotine in tobacco products and anti-smoking pharmaceuticals

• Boron-doped diamond electrode was used for sensitive determination of nicotine.
• Nicotine provided a single oxidation peak at highly positive potential of + 1.45 V.
• Low detection limit of 0.3 μM was achieved without any modification of electrode.
• Benefits of method: sensitivity, selectivity, precision and accuracy.
• Electrochemical sensor for quality control in tobacco and pharmaceutical industry.

A sensitive, selective and reliable electrochemical method for the determination of nicotine using differential pulse voltammetry on a bare boron-doped diamond electrode has been developed. Nicotine yielded a single oxidation peak at a highly positive potential of + 1.45 V (vs. Ag/AgCl/3 M KCl) in Britton–Robinson buffer solution at pH 8. The influence of supporting electrolyte, pH and scan rate on the current response of NIC was investigated. At optimized experimental conditions, a linear relation between peak current and concentration of nicotine was found for the range from 0.5 to 200 μM (0.08–32.9 mg L− 1) with a detection limit of 0.3 μM (0.05 mg L− 1) and a good repeatability (relative standard deviation of 2.1% at 25 μM concentration level, n = 10) was achieved without any electrode surface modification. The practical usefulness of the developed procedure was successfully demonstrated with the determination of nicotine in tobacco products and anti-smoking pharmaceuticals with results similar to those obtained by a high-performance liquid chromatography and to the contents declared by the manufacturer, respectively. Prior to analysis, the sample pretreatment includes only sonication and/or simple liquid–liquid extraction. The proposed sensor represents an effective electrochemical tool and a promising alternative for quality control analysis of products in tobacco and pharmaceutical industry.