暴露于环境烟气中的大鼠尿样代谢物分析

4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇(NNAL)是烟草特有亚硝胺4-(甲基亚硝胺基)-1-(3-吡啶)-1-丁酮(NNK)在生物体内的一种代谢标记物,分析暴露于烟气中的生物体内NNAL的含量是研究卷烟烟气对生物体健康影响的有效手段.基于人体的个体差异性很大,本文以饲养的大鼠为研究对象,采用LC-MS/MS...     

Liquid chromatography/tandem mass spectrometric method for the simultaneous determination of tobacco-specific nitrosamine NNK and its five metabolites

A sensitive and robust high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method to analyze 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its five metabolites in one passage was developed and validated. The method achieved excellent reproducibility and accuracy. Linearity was observed for all six compounds (R² = 0.999) with detection limits (S/N ≥ 3) ranging from 0.2 to 2.4 pg on column and 0.01-0.12 ng ml⁻¹ in samples injected. Average intra-day and inter-day variations (% R.S.D.) were 1.2 and 3.5%, respectively. A sample preparation method involving C8 and C18 solid phase extraction provided satisfactory recovery of the analytes in mouse urine. Each NNK metabolite was identified by its chromatographic retention time and specific fragmentation pattern. Since the carcinogenicity of NNK is related to its metabolism, the method described in this report should facilitate toxicological investigations into the carcinogenesis due to NNK exposure in the environment.     

烟草与尿样中的代谢标记物

卷烟烟气进入人体后会对人体的代谢物产生影响,目前研究较多的是稠环芳烃类、烟草特有亚硝胺类和尼古丁的代谢物。文章分别介绍了稠环芳烃类代谢物1-羟基芘,烟草特有亚硝胺类代谢物NNAL和NNAL-Gluc,尼古丁的代谢物可天宁,对这些代谢物的检测方法、体内的含量水平、各种条件的影响进行了综述。     

Liquid chromatographic/tandem mass spectrometric method for the determination of the tobacco-specific nitrosamine metabolite NNAL in smokers' urine

A specific and rapid liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method was developed and validated for NNAL, a metabolite of the tobacco-specific nitrosamine metabolite NNK. The metabolite was detected in smokers' urine with a limit of quantitation (LOQ) of 20 pg ml(-1) and a linear range up to 1000 pg ml(-1). The method features a single solid-phase extraction step and MS/MS monitoring following electrospray ionization. Fragmentation pathways for the protonated molecular ion are proposed. The sample preparation is simpler than that for gas chromatographic methods reported in the literature and maintains sensitivity adequate for determining NNAL in smokers' urine. By using enzyme hydrolysis to determine total NNAL in urine, the amount of NNAL-glucuronide was calculated. A standard pooled smokers' urine sample used for development gave values of 176 +/- 8 pg ml(-1) free NNAL and 675 +/- 26 pg ml(-1) total NNAL following enzyme hydrolysis. The method was applied to a group of seven smokers; the free NNAL level for the group was 101-256 pg ml(-1) with NNAL-glucuronides at 247-566 pg ml(-1). The ratio of conjugated to free NNAL was in the range 0.98-2.95. The variability in total daily amount of NNAL excreted (ng per 24 h) had RSDs of 6-21% for free NNAL, 7-22% for conjugated NNAL and 6-20% for total NNAL excreted. When normalized to the number of cigarettes smoked, the amounts of NNAL excreted per cigarette smoked were in the range of amounts of NNK yields reported for cigarettes in the literature.