Rapid Determination of Nicotine in Saliva by Liquid Phase Microextraction-High Performance Liquid Chromatography

A rapid, effective and ecofriendly method to determine nicotine in saliva by HPLC with liquid phase microextraction (LPME) as the sample preparation technique was introduced. The significant parameters affecting the LPME performance such as selection of microextraction solvent, extraction time, stirring rate, pH of sample solution and acceptor phase, and ionic strength were studied and optimized. The optimum experimental conditions were as follows: tri-n-butylphosphate as organic solvent, 17 min extraction time, 500 rpm stirring rate, 2 ml 0.05 M KOH to adjust the sample pH, acceptor phase pH = 3 and no addition of salt. Under the optimum conditions, the proposed method provided a linear range of 0.1–50 mg l−1 with r of 0.9996, detection limit of 0.05 mg l−1 (S/N = 3), RSD < 5% (n = 5) and relative recovery of 96.3%–102.2%.