title: Determination of tobacco-specific N-nitrosamines in rabbit serum by capillary zone electrophoresis and capillary electrophoresis-electrospray ionization-mass spectrometry with solid-phase extraction.
abstract: In this paper, we propose a new strategy for separation and determination of tobacco-specific N-nitrosamines (TSNAs), a group of strong carcinogens found only in tobacco products, by using CZE and CE-MS associated with SPE. Six TSNAs: N'-nitrosonornicotine, N'-nitrosoanatabine, N'-nitrosoanabasine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, and 4-(methylnitrosamino)-4-(3-pyridyl)-1-butanol were simultaneously separated by either of two CZE methods, one of which worked with ammonium formate buffer (pH 2.5) and another with citrate buffer (pH 2.4), as well as a CE-MS method. The CZE conditions including pH and concentration of running buffer, capillary length, applied voltage, and capillary temperature were systematically optimized. For CE-MS method, an optimized sheath liquid consisted of methanol-water was used at a flow rate of 10 muL/min. With SPE procedure, our proposed CE-MS method was successfully applied to determine TSNAs after 15 min metabolism in rabbits. A comparison study between CZE and CE-MS methods for quantitative purposes was carried out, showing that both methods provided similar separation efficiency, selectivity, repeatability, linearity, and recovery. However, CE-MS method was better suited for the analysis of TSNAs in complicated biological samples for its sensitivity and extra information on molecular structure. Having good accordance with our previous work by using LC-MS, the new CE-MS method is expected to be an alternative to the LC-MS method and applied to study the metabolism of TSNAs.
authors.affiliation: Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, PR China.
authors.forename: Chenchen
authors.initials: C
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
authors.forename: Dawei
authors.initials: D
authors.lastname: Wen
authors.forename: Jianxun
authors.initials: J
authors.lastname: Zhang
authors.forename: Weihong
authors.initials: W
authors.lastname: Cong
authors.forename: Bing
authors.initials: B
authors.lastname: Yu
authors.forename: Yiping
authors.initials: Y
authors.lastname: Liao
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009602:Nitrosamines / Q000097:blood* / Q000302:isolation & purification*; D011817:Rabbits; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013696:Temperature; D014026:Nicotiana / Q000737:chemistry*
chemical_list: D002021:Buffers; D009602:Nitrosamines