【作者】 刘兵；

【导师】 侯可勇；

【作者基本信息】 山东大学 ， 环境工程（专业学位）， 2022， 硕士

【摘要】 飞行时间质谱仪(TOFMS)检测质量范围宽,灵敏度和分辨率高,可在较短时间获取全部质量数范围的所有谱图信息。便携式质谱仪器已被广泛地应用于包括大气环境快速监测,化工产品过程实时监控、临床医学、工业设施检漏在内的很多领域。本文工作研制了一台基于真空紫外光(VUV)电离的便携式TOFMS,优化并评价了实验室自研的便携式TOFMS的性能。该仪器尺寸为400×340×250 mm,重17 kg,检测质量范围为m/z 15～500,在m/z 131处的分辨率为843,检测常见的苯系物以及麻醉剂七氟烷的检测限可达ppbv量级。在光电子电离(PEI)模式下,由光电效应产生的光电子利用电场调制能量,得到高于10.6 eV的电子,并且使用磁场增强电子电离效率,电离能高于10.6 eV光子能量的化合物实现电离。PEI是冷电子,电离源不受水汽的影响,分子离子峰占主导,离子碎片较少,谱图简单,方便分析。基于便携式磁场增强光电子电离(MEPEI)TOFMS,开发了手术全麻患者呼出气中的七氟烷浓度即时(POC)检测方法,探索呼出气中七氟烷浓度与术后躁动症状相关性,并且根据患者呼出气中七氟烷浓度制定了躁动症确认与治疗措施。MEPEI-TOFMS直接分析高湿度呼出气中的七氟烷,获得其特征离子[C4H3F6O]+(m/z 181),分析时间仅60 s。七氟烷定量相对标准差(RSD)仅为1.24%。46例儿童患者中有4例有躁动症状,并分析了术后躁动症状与呼出气中七氟烷浓度的关系,发现躁动患者苏醒时七氟烷浓度的临界值为500 ppmv,并提出了七氟烷与丙泊酚共用新方案以降低患者术后躁动概率。新开发的便携式MEPEI-TOFMS也成功地应用在医疗环境中七氟烷浓度的检测。POC检测的临床实验结果表明该方法具有低成本、方便、准确等特点,在临床质谱的发展上具有很高的潜力。基于便携式TOFMS开发了城市天然气管道检漏的Ne气示踪分析新方法。便携式TOFMS 直接检测 18～1000 ppmv、1000～20000 ppmv 以及 20000～300000 ppmv 三个浓度段的示踪剂Ne气,样品的定量曲线相关系数优于0.98,RSD值为12.38%,该结果完全满足Ne气示踪法对天然气管道检漏实验要求。便携式TOFMS现场分析单样品时间仅为60 s,通过地面的打孔采样气Ne的浓度迅速、准确地定位泄漏点,得到的结果和离线色谱检测方法完全一致,便携式TOFMS可同时检测天然气中主要成分CH4的大气泄漏情况,进一步验证了了 Ne气示踪法对天然气管道检漏的可行性。本研究对天然气管道的快捷高效检漏研究具有指导意义。更多还原

【Abstract】 Time-of-flight mass spectrometer(TOFMS)features simpler working principle,wide range of mass measurement,and relatively high resolution and sensitivity,which can obtain the whole spectrum information of the full mass range in a short time.Miniature MS has been used widely in the field of fast speed online detection for environment,process monitoring for chemical plant,clinical medicine and leak detection of industrial facilities.In this thesis,we mainly developed a miniature TOFMS based on the vacuum ultraviolet(VUV)photo ionization technology,and optimized the performance of the miniature TOFMS self-developed by our laboratory.The dimension of the instrument is 400×340×250 mm,weighs 17 kg,and has the detection mass range of m/z 15 to 500.The resolution is 843 at m/z 131,and the detection limit of benzene compounds and anesthetic sevoflurane can be up to the order of ppbv.In the photoelectron ionization(PEI)mode,the photoelectron under the action of electric field has an energy higher than 10.6 eV,and can ionize substances with higher energy.The PEI ionization source is not affected by water vapor and produces fewer ion fragments,and the molecular ion peak occupies the main position in the spectrum.A magnetic field enhanced photoelectron ionization(MEPEI)miniature TOFMS has been developed for point-of-care detection and verification the relationship between postoperative agitation symptoms and sevoflurane concentration in exhaled breath.The MEPEI is water vapor resistant and can directly ionize sevoflurane through capillary sampling and obtain its characteristic ion[C4H3F6O]+(m/z 181),and the analysis time of exhaled breath is only 60s.Three standard curves were formulated to quantitively detect sevoflurane in different scenarios,the coefficient of determination(R2)was higher than 0.9882 and the relative standard deviation(RSD)of signal intensity was only 1.24%.The results showed that four of the 46 children patients had agitation symptoms.The newly miniature MEPEI-TOFMS was also successfully used to evaluate the concentration of sevoflurane in medical environment.The real-time monitoring of sevoflurane concentration in exhalation indicates the potential of this method for low-cost and convenient point-of-care(POC)detection and diagnosis of agitation symptoms.A new method for leakage detecting of natural gas pipeline by miniature TOFMS,namely Ne Gas Tracer Method,was developed.In the experimental phase,Ne gas was detected by the optimized miniature TOFMS and it was directly divided into three concentration range:18-1000 ppmv,1000-20000 ppmv and 20000-300000 ppmv,with a quantitative curve correlation coefficient above 0.98 and RSD of 12.38%.The results fully met the requirements of the Ne gas trace method for natural gas pipeline leak detection experiments and miniature TOFMS was applied to the experimental site,the trend of the results obtained is completely consistent with the chromatographic results.The detection time of a single sample is only 60 s,and the presence of the main component CH4 in natural gas can be detected simultaneously.It also proves that natural gas and tracer Ne gas can be fully and evenly mixed,which further proves the feasibility of Ne gas trace method for natural gas pipeline leakage detection.This study is instructive for the fast and efficient leakage detection study of natural gas pipeline.更多还原