Development of a Quantitative and Sensitive Liquid Chromatographic/Mass Spectrome

研究得出的结论是，尽管非洲裔美国人的戒烟率低于美国白人， 事实上，这个群体每天吸烟的数量比美国白人少 (1-4)。此外，非洲 美国人与烟草相关的发病率高得不成比例 (5-7)。我假设 由于新陈代谢能力差，非裔美国人戒烟可能会更加困难 有效地尼古丁及其代谢物。因此，本研究将尝试确定是否存在 非裔美国人的戒烟率与其烟碱代谢特征之间的相关性。 该研究项目将使用 LC/MS 测量非裔美国人的烟碱代谢特征 参加戒烟诊所。将开发改进的 LC/MS 方法，以增强 检测尼古丁及其主要代谢物可替宁、反式-3'-OH-可替宁、 烟碱 N'-氧化物、4-OH-4-(3-吡啶基)-丁酸、烟碱-A/-葡萄糖醛酸、可替宁-A/-葡萄糖醛酸和反式- 尿液样本中的 3'-OH-可替宁-O-葡萄糖醛酸苷。改进的 LC/MS 方法将纳入 q-TOF 质量 分析仪相对于当前的 LC/MS（ESI 四极杆）扩展了所开发方法的灵敏度和准确性 迄今为止实践中的方法。该项目将重点关注从非洲隔离尿液样本 参加戒烟诊所的美国人。将分析样品并确定尼古丁含量 及其主要代谢物可替宁进行了定量。同样，该研究项目将建立以下代谢特征： 非裔美国人参加戒烟诊所并调查是否有 戒烟率和代谢特征之间的相关性。 研究还得出结论，暴露于环境烟草烟雾 (ETS) 导致了大部分的健康问题。 非吸烟者的癌症病例 (8,9)。由于烟草中致癌代谢物的水平较低 对于非吸烟者的尿液样本，需要一种可靠且简单的提取方法来测量尼古丁 代谢物。目前的提取方法过于繁琐且耗时。此外，由于 由于尼古丁的降解动力学和耗时的制备时间，提取方法可以 导致尿样中尼古丁定量的误差。该研究项目将扩大研究范围 该研究是在 PSCOM 的 Gang Chen 博士的实验室中进行的，并专注于开发一个强大、可靠的 从非吸烟者的尿液中提取尼古丁及其代谢物的方法。这样做的主要目的 研究项目的组成部分是为了让研究人员能够更好地熟悉程序 以及与进行临床研究和癌症相关研究相关的实践。具体目标 本研究项目如下： 具体目标： 1. 使用四极杆飞行时间质谱仪 (qTOF) 开发定量 LC/MS 方法 检测尿液样本中低含量的尼古丁及其主要代谢物。 2. 应用开发的qTOF方法研究非裔美国人的代谢概况 尝试戒烟。 3. 开发更好的从SHS尿样中提取尼古丁及其代谢物的方法。 4. 继续陈刚博士开发的现有研究和技术来测量低水平 暴露于环境烟草烟雾 (ETS) 的非吸烟者 (SHS) 中的尼古丁及其代谢物

Studies conclude that the cessation rates amongst African Americans are lower than White Americans despite the fact that this group smokes fewer cigarettes per day than White Americans (1-4). Furthermore, African Americans experience disproportionately higher rates of tobacco-related morbidity (5-7). I hypothesize that African Americans may have a more difficult time with quitting smoking because of their inability to metabolize nicotine and its metabolites efficiently. As a result, this research will attempt to determine if there is a correlation between smoking cessation rates amongst African Americans and their nicotinic metabolic profile. This research project will use LC/MS to measure the nicotinic metabolic profile of African Americans participating in smoking cessation clinics. An improved LC/MS method will be developed enhancing the sensitivity and accuracy of detection of nicotine and its major metabolites, cotinine, trans-3'-OH-cotinine, nicotine N'-oxide, 4-OH-4-(3-pyridyl)-butanoid acid, nicotine-A/-glucuronide, cotinine-A/-glucuroninde and trans- 3'-OH-cotinine-O-glucuronide, in urine samples. The improved LC/MS method will incorporate a q-TOF mass analyzer extending the sensitivity and accuracy of the developed method relative to the current LC/MS (ESIquadrupole) methods in practice to date. The project will focus on sequestering urine samples from African Americans participating in smoking cessation clinics. The samples will be analyzed and the levels of nicotine and its major metabolite, cotinine, quantified. Again, the research project will establish a metabolic profile of African Americans participating in a smoking cessation clinic and investigate whether or not there is a correlation between cessation rates and metabolic profile. Studies also conclude that exposure to environmental tobacco smoke (ETS) contributes to a majority of the cancer cases amongst non-smokers (8,9). Because of the low-levels of cancer causing tobacco metabolites in the urine sample of non-smokers, a reliable and simple extraction method is needed to measure nicotine metabolites. Current extraction methods are too cumbersome and time-consuming. Furthermore, because of the kinetics of degradation of nicotine and the time-consuming preparation times, the extraction methods can induce errors in quantitation of nicotine in urine samples. This research project will expand the studies conducted in the laboratory of Dr. Gang Chen at PSCOM, as well as focus on developing a robust, reliable method to extract nicotine and its metabolites from the urine of non-smokers. The main purpose of this component of the research project is so that the researcher can become better acquainted with the procedures and practices in place related to conducting clinical research and cancer related research. The specific aims of this research project are as follows: Specific Aims: 1. To develop a quantitative LC/MS method using a quadrupole time-of-flight mass spectrometer (qTOF) to detect low levels of nicotine and its major metabolites, in urine samples. 2. To apply the developed qTOF method to investigate the metabolic profile of African-Americans attempting to quit smoking. 3. To develop better extraction methods of nicotine and its metabolites from urine samples of SHS. 4. To continue existing research and technology developed by Dr. Gang Chen to measure low levels of nicotine and its metabolites in non-smokers (SHS) exposed to environmental tobacco smoke (ETS)