Biomedical applications of cotinine quantitation in smoking related research

Two studies were undertaken to assess the variability of cotinine concentrations in different biological fluids and to determine the most desirable fluid to use for specific experimental protocols. For protocols validating smoking cessation, plasma or urinary cotinine determinations provided the most accurate indicators of compliance. In studies where smokers switched from high yield to low yield cigarettes, plasma cotinine determinations were good indicators of smoker behavior. Correct interpretation of smoker status is dependent on the biological fluid selected for cotinine analysis.