Sensitive Chromogenic Spectrophotometric Method for the Determination of Nicotine Using 1 [Bromomethyl(phenyl) methyl]-2-(2,4-dinitrophenyl) hydrazine

Abstract

This study aimed to establish an efficient analytical method for the detection and quantification of nicotine using 1-[(bromomethyl)(phenyl)methyl]-2-(2,4-dinitrophenyl) hydrazone (BPMDNPH) as derivatizing reagent. The proposed method is based on a simple, rapid, and highly sensitive spectrophotometric approach. The work included the determination of the optimum absorption wavelength as well as the evaluation of the complex stability time to ensure accurate measurements. Nicotine was quantified spectrophotometrically at the maximum absorption wavelength (λmax = 455 nm). The measured nicotine concentrations ranged from 0.16 to 0.97 ppm, with a detection limit (LOD) of 0.13577 μg mL⁻¹. Additional analytical performance parameters, including the limit of quantification (LOQ) and method sensitivity, were also determined. The calibration curve showed excellent linearity, with a correlation coefficient (R²) of 0.99105 and a molar absorptivity of 4.9 × 10⁴ L·mol⁻¹·cm⁻¹. The stability of the BPMDNPH–nicotine complex was assessed under the optimum experimental conditions. The findings indicated that the absorbance of the BPMDNPH complex remained stable throughout the monitoring period. The developed method was successfully applied to determine nicotine in tobacco products marketed locally in Libya. The obtained results revealed deviations ranging from 0.06 to 0.21 (SD) from the labeled values, with an overall relative standard deviation (RSD%) of 1.8%.