Voltammetric determination of nicotine in electronic cigarette liquids using a boron-doped diamond electrode (BDDE)

A simple, sensitive and rapid method of nicotine determination using Boron Doped Diamond Electrode (BDDE) and Differential Pulse Voltammetry (DPV) in electronic cigarette liquids was described. To the best of our knowledge, this is the first presentation of voltammetric method for the determination of nicotine in this type of complex samples. In presented conditions, nicotine undergoes irreversible two-electron oxidation controlled by diffusion process. Optimal measurement parameters were achieved using solution of 25% ammonia in 0.1 mol/L ammonium chloride at pH 7.5 as supporting electrolyte. The calibration graph was linear from 0.03–0.40 mg/L of nicotine, the detection limit was 0.01 mg/L with the correlation coefficient of 0.9950. Sample preparation requires only dilution of the liquid. The effective application of the described simply measurement procedure significantly extends the use of the BDD electrode as an electrochemical sensor. It enables the electrochemical detection of nicotine in samples with a complex chemical composition like liquids for e-cigarettes, which is important in the case of a limited and controlled nicotine concentration in these products. [Display omitted] •A new procedure for determining nicotine using BDD electrode was described.•The proposed method is rapid, sensitive, simple and repeatable.•Nicotine content in commercial e-cigarette liquids was determined.•It is the first voltammetric procedure for determining nicotine in this type of matrix.•No compliance between determined content and the manufacturer's declaration was detected.