ANALYSIS OF NICOTINE AS A TRICHLOROETHYL CARBAMATE BY GAS-CHROMATOGRAPHY WITH ELECTRON-CAPTURE DETECTION

Nicotine was subjected to reaction at 90° with trichloroethyl chloroformate in the presence of pyridine to form a carbamate in which the pyrolidine ring was opened. Upon heat treatment, this carbamate partially formed the corresponding olefin. About 10 pg could be detected with an electron-capture detector and 60 pg with an alkali flame-ionization detector. The extraction was studied with 14C-labelled nicotine. Methylene chloride was suitable for extraction from diluted plasma, whereas toluene containing 5% of heptafluorobutanol was used in a re-extraction step and also as the chloroformate reaction medium. Due to a nicotine blank the limit for quantitative determination was 10 ng/ml in plasma (sample volume 1 ml). N-n-Propylnornicotine was used as an internal standard. The precision at the 30 ng/ml level was ±8.8% (n = 7). © 1979.