Sensitive and simple method for the determination of nicotine and continine in human urine, plasma and saliva by gas chromatography-mass spectrometry.

A method is proposed for the determination of nicotine and cotinine in human urine, plasma and saliva. Nicotine and cotinine were extracted from alkalinized sample with ethyl ether and concentrated to minimum volume with nitrogen stream. The volatility of nicotine was prevented by the addition of acetic acid to the organic solvent during evaporation. Peak shapes and quantitation of nicotine and cotinine are excellent, with linear calibration curves over a wide range of 1–10 000 ng/ml. The detection limits of nicotine and cotinine are 0.2 ng/ml in urine and 1.0 ng/ml in plasma and saliva. The intra-day precision of nicotine and cotinine in all samples was