Simultaneous determination of nicotine and cotinine in human plasma by nitrogen detection gas-liquid chromatography

• Published in: Journal of forensic sciences Vol. 26; no. 1; p. 6
• Main Authors: Kogan, M J, Verebey, K, Jaffee, J H, Mulé, S J
• Format: Journal Article
• Language: English
• Published: United States 01-01-1981
• Subjects: Chromatography, Gas - methods; Cotinine - blood; Humans; Nicotine - blood; Nitrogen - analysis; Pyrrolidinones - blood
• ISSN: 0022-1198
• DOI: 10.1520/JFS11324J

Human plasma levels of nicotine and its principal metabolite, cotinine, were simultaneously quantitated by gas-liquid chromatography combined with nitrogen selective detection. Nicotine, cotinine, and the added internal standard ketamine are extracted from plasma at basic pH into methylene chloride, back-extracted into acid, and then re-extracted into methylene chloride. Analysis is carried out on a packed glass column of 3% SE-30 while column temperature is programmed from 150 to 200 degrees C. Detector response is linea over the range of 2 to 50 ng/mL nicotine and 50 to 500 ng/mL cotinine. The method was validated on 150 plasma samples obtained from habitual smokers. Mean levels of 19.5 and 219 ng/mL were found for nicotine and cotinine, respectively. Both the mean and the range of the levels were in agreement with previously reported plasma levels for nicotine and cotinine.