Spectrophotometric Determination of Nicotine in Cigarette Tobacco in Libyan Market Using Iron (III) and Potassium Ferricyanide

Abstract

A new simple, accurate, sensitive and economical procedure for the estimation of nicotine is described. In the presence of potassium ferricyanide, it has been demonstrated that Fe3+ is reduced to Fe2+ by nicotine in acidic medium. In addition, soluble Prussian blue (KFe[Fe(CN)6]) was produced by the reaction between the formed Fe2+ and potassium ferricyanide. The absorbance of soluble Prussian blue is measured at the absorption maximum of 736 nm. Beer's law is obeyed in the concentration range 0.1-4.4 μg/ml. The molar absorptivity is 3.05 x 104 l/mol.cm. Sandell sensitivity is 5.32 ng/cm2. The limits of detection as well as quantification are reported. Sex replicate analyses (n=6) of solutions containing three different concentrations of nicotine was carried out. The percent error and the RSD values have been reported. The proposed method was applied to the determination of nicotine in cigarette tobacco present in Libya and the results demonstrate that the method is equally accurate and precise as found from the t- and F-values. The reliability of the method was established by recovery studies using standard-addition technique.