Head space single-drop microextraction of pyridine from nargile smoke and determination by high-performance liquid chromatography

This study aimed to apply the headspace single-drop microextraction (HS-SDME) method for extracting and determining pyridine in nargile smoke samples, followed by high-performance liquid chromatography (HPLC). We optimised the different parameters to evaluate the HS-SDME process. The optimum conditions were 2.5 µL of toluene as the extracting solvent, 150 s as the optimal extraction time, ionic strength of 15% NaCl and stirring of the solution at 700 rpm. Under the optimal conditions, the HS-SDME–HPLC technique has a linear range for pyridine between 0.05 and 30.0 µg L⁻¹, with a minimum limit of detection (LOD) of approximately 0.028 µg L⁻¹. Statistical data showed good accuracy and precision. The proposed method can be used for microextraction and analyses of ultra-trace amounts of pyridine in nargile smoke samples.