Hartvig P, Ahnfelt N O, Hammarlund M, Vessman J
J Chromatogr. 1979 May 11;173(1):127-38. doi: 10.1016/s0021-9673(01)80452-0.
Nicotine was subjected to reaction at 90 degrees with trichloroethyl chloroformate in the presence of pyridine to form a carbamate in which the pyrrolidine 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 determinations 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).
