人体呼出气中挥发性有机物直接质谱分析装置组建及表征

发布时间：2018-04-27 01:20

本文选题：人体呼出气 + 挥发性有机物　；参考：《暨南大学》2017年硕士论文

【摘要】：二次电喷雾电离质谱技术(Secondary electrospray ionization mass spectrometry,SESI-MS)以普适性的软电离源——SESI源为技术特色,可实现呼出气中挥发性有机化合物(Volatile organic compounds,VOCs)的实时直接分析,如采用高分辨质谱(High resolution mass spectrometry,HRMS,分辨率R10000),能够进一步提高定性分析的准确性、获取化合物准确元素组成,是推进人体呼出气中VOCs在疾病诊断、环境健康等研究中转化应用的关键。但目前,不同实验室自组建的SESI源(尚无商品源)缺乏统一标准,实验结果缺乏可比性;其次,HRMS的质量分辨率和准确度对呼出气中VOCs定性分析的影响尚属未知。因此,本论文的研究内容为设计并组建灵敏度高、重现性好的SESI源,并表征SESI-HRMS的重要参数,如重现性、质量分辨率、质量准确性。重要结果如下:(1)在高性能的商业nanoESI源的基础上,自行设计并组建二次纳流电喷雾电离源Sec-nanoESI(Secondary nanoESI),与四极杆组合静电场轨道阱高分辨质谱(HRMS)耦合。正常人呼出气分析结果均表明,Sec-nano ESI-HRMS检测呼出气中单个化合物的离子峰强度以及单次呼气过程中离子峰强度随时间的变化趋势,均具有可重现性。(2)采用质量分辨率R=120000时,可以有效分离同重化合物;筛选出正、负离子检测模式下的标准化合物,并建立准确质量数对照表,可用于获取分子量为50 500 Da化合物的准确元素组成。(3)在50 300 Da范围内,在正常人呼出气中,除文献报道的化合物外,还检出了二氯苯、硫酸盐、硅酸盐、磷酸盐等以往研究中极少报道的化合物,其中二氯苯推测来自吸入VOCs,硫酸盐、硅酸盐、磷酸盐等非挥发性化合物推测来自呼出气中的颗粒物。在300 500 Da范围内,检出了29种相对高分子量化合物,这些化合物的环双键当量均值4.5,具有较高不饱和度。上述化合物的检出,或有助于更准确地理解呼出气中VOCs的来源和产生机制。
[Abstract]:Secondary electrospray ionization mass spectrometry (SESI-MS), which is characterized by a general soft ionization source, can be used to analyze volatile organic compounds (VOCs) in exhaled air in real time and directly. If high resolution mass spectrometric HRMS is used, the accuracy of qualitative analysis can be further improved and the accurate composition of compounds can be obtained. It is the key to promote the transformation and application of VOCs in human exhalation in disease diagnosis and environmental health. But at present, there is no uniform standard for the SESI source (no commodity source) in different laboratories, and the experimental results are not comparable. Secondly, the effect of quality resolution and accuracy on the qualitative analysis of VOCs in exhaled air is unknown. Therefore, the research content of this thesis is to design and construct SESI source with high sensitivity and good reproducibility, and to characterize the important parameters of SESI-HRMS, such as reproducibility, quality resolution and quality accuracy. The important results are as follows: (1) based on the high performance commercial nanoESI source, we designed and constructed the secondary NCSI ionization source Sec-nanoESI(Secondary nanoESI, which is coupled with the quadrupole combined electrostatic field trap high resolution mass spectrometry (HRMS). The results of exhalation analysis showed that the ion peak strength of single compound in exhaled air and the variation trend of ion peak strength with time during exhalation were determined by Sec-nano ESI-HRMS, which were reproducible when the mass resolution was R = 1200000. The standard compounds in the positive and negative ion detection mode can be screened out, and the accurate mass number comparison table can be established, which can be used to obtain the exact element composition of the molecular weight of 50 ~ 500Da compounds, and can be used in the range of 50 ~ 300Da. In addition to the compounds reported in the literature, dichlorobenzene, sulfate, silicate, phosphate and other compounds have been detected in the exhalation of normal people, among which dichlorobenzene is supposed to come from inhalation of VOCs, sulfate, silicate, etc. Non-volatile compounds, such as phosphate, presumably come from particulates in the exhaled air. In the range of 300 ~ 500Da, 29 relative high molecular weight compounds were detected. The mean value of ring double bond equivalent of these compounds was 4.5, with high unsaturation. The detection of these compounds may contribute to a more accurate understanding of the origin and mechanism of VOCs in exhalation.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.63

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