title: Characteristic fragmentation behavior of tobacco-specific N-nitrosamines using electrospray ionization multistage tandem mass spectrometry incorporating deuterium labeling.
abstract: BACKGROUND
  Tobacco-specific N-nitrosamines (TSNAs) mainly include 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), N-nitrosoanabasine (NAB) and N-nitrosoanatabine (NAT) that are formed from tobacco alkaloids during the curing process and contained in tobacco and tobacco smoke. They are linked with carcinogenesis. Analytical methods for quality control of products and determination of their metabolites are therefore of great importance.
  
  
  METHODS
  The characteristic fragmentation behaviors of tobacco-specific TSNAs have been studied by electrospray ionization multistage tandem mass spectrometry. The deutero-labeled TSNA compounds have also been employed to clarify the fragmentation mechanism, which further confirms the proposed fragmentation patterns.
  
  
  RESULTS
  Detailed analysis of the resultant fragments shows there are two different kinds of fragmentation patterns with the general fragment backbone of pyrrolidine or piperidine rings. In one route, pyrrolidine or piperidine rings undergo direct fragmentation and form some stable intermediates without affecting the parent rings. The other, however, involves ring opening and then ring closure at the pyridine-2 carbon atom to form multi-membered rings.
  
  
  CONCLUSIONS
  This characteristic fragmentation behavior therefore provides useful information on identification of TSNAs that may be used to monitor such kinds of compound in the biological metabolism.
authors: Technology Center, China Tobacco Zhejiang Industrial Co., Ltd, Hangzhou, 310024, P.R. China.
authors: An-Fu
authors: AF
authors: Hu
authors: Jian
authors: J
authors: Jiang
authors: Guo-Jun
authors: GJ
authors: Zhou
authors: Jun
authors: J
authors: Yang
authors: Wei-Qiang
authors: WQ
authors: Xiao
authors: Jian
authors: J
authors: Xu
mesh_terms: D000465:Algorithms; D003903:Deuterium / Q000737:chemistry*; D007553:Isotope Labeling; D009602:Nitrosamines / Q000032:analysis* / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D009602:Nitrosamines; D010936:Plant Extracts; D003903:Deuterium