Determination of the natural abundance delta15N of nicotine and related alkaloids by gas chromatography/isotope ratio mass spectrometry.
A method is described by which the natural abundance delta15N values of nicotine, analogues, and metabolites can be determined. The alkaloids are extracted from their biological matrix by solid-phase extraction and analysis is conducted using isotope ratio mass spectrometry interfaced to gas chromatography. Repeatability and precision are sufficient to allow differences in the delta15N values of less than 1.0 per thousand to be satisfactorily measured, with a standard deviation routinely less than 0.5 per thousand. The methodology has been tested by determining the changes in the delta15N values of nicotine, N-methyl-2-phenylpyrrolidine and their respective demethylation products, nornicotine and 2-phenylpyrrolidine, during biotransformation by cell suspension cultures of Nicotiana species. Sufficient precision and reproducibility were obtained to allow the kinetic isotope effects associated with the demethylation reaction to be calculated.
Molinié
Roland
R
Laboratory of Isotopic and Electrochemical Analysis of Metabolism (LAIEM), CNRS UMR6006, University of Nantes, 2 rue de la Houssinière, 44322 Nantes, France.
Ferchaud-Roucher
Véronique
V
Lebreton
Jacques
J
Robins
Richard J
RJ
D000470:Alkaloids / Q000032:analysis / Q000737:chemistry; D002478:Cells, Cultured; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods* / Q000592:standards; D009538:Nicotine / Q000032:analysis* / Q000737:chemistry; D018722:Nicotinic Agonists / Q000032:analysis* / Q000737:chemistry; D009587:Nitrogen Isotopes / Q000032:analysis; D015203:Reproducibility of Results; D014026:Nicotiana / Q000737:chemistry* / Q000166:cytology
D000470:Alkaloids; D018722:Nicotinic Agonists; D009587:Nitrogen Isotopes; D009538:Nicotine