Determination of Nicotine and Cotinine in Urineby Headspace Solid Phase Microextraction Gas Chromatography with Mass Spectrometric Detection

Irena Brčić Karačonji,* Ljiljana Skender, Višnja Karačić

Clinical Toxicological Chemistry Unit, Institute for Medical Research and Occupational Health, Ksaverska c. 2,Post Office Box 291, HR-10001 Zagreb, Croatia.

Paper based on a presentation at the 12th International Symposium on Separation Sciences, Lipica, Slovenia,
September 27–29, 2006.

A simple and rapid method for determination of low concentrations of nicotine and cotinine in urine has been developed. The method is based on headspace solid phase microextraction (HS-SPME) followed by gas chromatographic determination and mass spectrometric detection (GC-MS). The calibration curves were linear (r > 0.9998) over the concentration range tested (1–500 µg L–1), with detection limits of 1.1 µg L–1 and 0.9 µg L–1 for nicotine and cotinine, respectively. The repeatability for nicotine and cotinine (expressed as relative standard deviation) was < 9%. The accuracy of the method ranged from 90 to 99%.
The method was applied for the quantitative analysis of nicotine and cotinine in urine samples collected from 30 nonsmokers, 15 without any environmental tobacco smoke (ETS) exposure (group I) and 15 who reported exposure to ETS (group II). There were statistically significant differences between groups I and II for nicotine (p < 10–4; ranges 2.1–28.0 and 10.1–499.7 µg L–1) and cotinine (p < 10–5; ranges < 0.9–15.0 and 14.5–200.9 µg L–1).
Good sensitivity, short analysis time, small sample volume, no solvent use and sample preparation, make the method convenient for determination of nicotine and cotinine in nonsmokers’ urine.

Keywords: cotinine, nicotine, nonsmokers, urine, HS-SPME, GC-MS.