Li Chenchen, Chen Zheng, Wen Dawei, Zhang Jianxun, Cong Weihong, Yu Bing, Liao Yiping, Liu Huwei
Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, PR China.
Electrophoresis. 2006 Jun;27(11):2152-63. doi: 10.1002/elps.200600009.
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.
在本文中，我们提出了一种新策略，通过使用与固相萃取（SPE）联用的毛细管区带电泳（CZE）和毛细管电泳-质谱联用（CE-MS）技术，来分离和测定烟草特有亚硝胺（TSNAs），这是一类仅在烟草制品中发现的强致癌物。六种TSNAs：N'-亚硝基降烟碱、N'-亚硝基新烟草碱、N'-亚硝基假木贼碱、4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮、4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇和4-(甲基亚硝胺基)-4-(3-吡啶基)-1-丁醇，可通过两种CZE方法中的任意一种同时分离，其中一种方法使用甲酸铵缓冲液（pH 2.5），另一种使用柠檬酸盐缓冲液（pH 2.4），以及一种CE-MS方法。对CZE的条件进行了系统优化，包括运行缓冲液的pH值和浓度、毛细管长度、施加电压以及毛细管温度。对于CE-MS方法，使用了由甲醇-水组成的优化鞘液，流速为10 μL/min。通过SPE程序，我们提出的CE-MS方法成功应用于测定兔子体内15分钟代谢后的TSNAs。对CZE和CE-MS方法进行了定量比较研究，结果表明两种方法具有相似的分离效率、选择性、重复性、线性和回收率。然而，CE-MS方法因其灵敏度和分子结构的额外信息，更适合分析复杂生物样品中的TSNAs。新的CE-MS方法与我们之前使用液相色谱-质谱联用（LC-MS）的工作结果高度一致，有望成为LC-MS方法的替代方法，并应用于研究TSNAs的代谢。
