Li Chenchen, Wen Dawei, Zhang Jianxun, Chen Zheng, Cong Weihong, Rao Zhihua, Liu Huwei
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.
Anal Bioanal Chem. 2006 Dec;386(7-8):1985-93. doi: 10.1007/s00216-006-0884-5. Epub 2006 Oct 27.
Metabolism of four tobacco-specific N-nitrosamines (TSNAs), N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) has been studied by solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS-MS). 4-(Methylnitrosamino)-4-(3-pyridyl)-1-butanol (iso-NNAL) was used as internal standard. SPE and LC-MS-MS was found to be a rapid, simple, sensitive, and selective method for analysis of TSNAs in rabbit serum. The relative standard deviation (R.S.D., n = 6) for analysis of 5 ng mL(-1) and 0.5 ng mL(-1) standards and of serum sample spiked with 5 ng mL(-1) standards of five TSNAs was 2.1-11% and recovery of 5 ng mL(-1) standards from serum was 100.2-112.9%. A good linear relationship was obtained between peak area ratio and concentration in the range of 0.2-100 ng mL(-1) for NNAL and 0.5-100 ng mL(-1) for other four TSNAs, with correlation coefficients (R2) >0.99 (both linear and log-log regression). Detection limits for standards in solvent were between 0.04 and 0.10 ng mL(-1). Doses of TSNAs administered to rabbits via the auricular vein were 4.67 microg kg(-1) and 11.67 microg kg(-1), in accordance with the different levels in cigarettes. Metabolic curves were obtained for the four TSNAs and for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of NNK; on the basis of these curves we modeled metabolic kinetic equations for these TSNAs by nonlinear curve fitting.
采用固相萃取（SPE）和液相色谱 - 串联质谱法（LC - MS - MS）研究了四种烟草特有亚硝胺（TSNAs），即N'-亚硝基降烟碱（NNN）、N'-亚硝基新烟草碱（NAT）、N'-亚硝基假木贼碱（NAB）和4 - （甲基亚硝胺基） - 1 - （3 - 吡啶基） - 1 - 丁酮（NNK）的代谢情况。以4 - （甲基亚硝胺基） - 4 - （3 - 吡啶基） - 1 - 丁醇（异 - NNAL）作为内标。结果发现，SPE和LC - MS - MS是一种快速、简便、灵敏且具有选择性的分析兔血清中TSNAs的方法。分析5 ng mL⁻¹和0.5 ng mL⁻¹标准品以及添加了5 ng mL⁻¹五种TSNAs标准品的血清样品时，相对标准偏差（R.S.D.，n = 6）为2.1% - 11%，从血清中回收5 ng mL⁻¹标准品的回收率为100.2% - 112.9%。对于NNAL，在0.2 - 100 ng mL⁻¹范围内，峰面积比与浓度之间呈现良好的线性关系；对于其他四种TSNAs，在0.5 - 100 ng mL⁻¹范围内呈现良好的线性关系，相关系数（R²）>0.99（线性和对数 - 对数回归）。溶剂中标准品的检测限在0.04至0.10 ng mL⁻¹之间。根据香烟中不同的含量水平，通过耳静脉给兔子注射的TSNAs剂量分别为4.67 μg kg⁻¹和11.67 μg kg⁻¹。获得了四种TSNAs以及NNK的代谢产物4 - （甲基亚硝胺基） - 1 - （3 - 吡啶基） - 1 - 丁醇（NNAL）的代谢曲线；基于这些曲线，我们通过非线性曲线拟合为这些TSNAs建立了代谢动力学方程。
