A RAPID GAS-LIQUID-CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF COTININE AND NICOTINE IN BIOLOGICAL-FLUIDS

Abstract— A rapid method is described for the simultaneous measurement of nicotine and cotinine in biological fluids using capillary column gas‐liquid chromatography. Using 100 μL sample volume the lower limit of detection for both nicotine and cotinine was 100 pg mL−1, allowing the method to be used for the measurement of these compounds in both smokers and non‐smokers. The extraction time is 3 min per sample, and by using multi‐pipetting and vortexing systems 250 samples can be extracted per day. The average coefficient of variation over the nicotine range 10 to 100 ng mL−1 was 3.9% and for cotinine over the range 1.0 to 1000 ng mL−1 was 2.2%. Saliva cotinine concentrations were quantitatively related to passive exposure to parental smoking in a population study of 1118 non‐smoking schoolchildren. 1990 Royal Pharmaceutical Society of Great Britain