实时发动机排气分析，具有超敏感的PTR-TOFMS

空气污染的主要来源归因于汽车排气。汽车，船只，飞机，发电厂等用于燃烧发动机释放了许多空气污染物，这些空气污染物已被证明对公共卫生和自然环境有许多不同的负面影响。

Image Credit: Shutterstock/khunkorn

因此，燃烧引擎的排放测试已成为集中研究的重点。除了包括氮氧化物（NOX），一氧化碳（CO），颗粒物和硫氧化物（SOX）的排放，挥发性有机化合物（VOC）及其大气光化学反应产品也引起了很多关注，因为他们对气氛的负面影响及其对公共卫生的危害。

PTR-MS是一种分析方法，可以实时量化具有高灵敏度的碳氢化合物和VOC。实时监测排放的能力主要用于检查燃烧过程中的快速变化条件并评估控制技术的影响。特别是，飞机发动机的汽车或闲置阶段的初步冷启动阶段，这对大量排放化合物以及硬加速阶段负责，需要实时（或在线）分析。查看排气组合能够检查哪些参数和过程对这些排放负责。

Major Reasons Customers Choose PTR-TOFMS to Monitor Exhaust Emissions:

• Emission rates alter rapidly with engine operating conditions, and hence a high time resolution measurement is vital
• High sensitivity and good separation of isobaric compounds
• In contrast to offline methods, real-time analysis enables the measurement of critical compounds. For instance, acrolein is an unstable compound which may easily get lost in an offline sampling procedure

Examples of Real-Time Engines Emission Monitoring with PTR-MS

柴油排气或压缩点火的测量已成为研究人员的目标PTR-MS。2005年，Jobson等人。使用基于四极的PTR-MS来评估柴油发动机的VOC排放。他们使用PTR-MS的主要原因是

• in-situ (real-time) capability of the instrument, and the
• efficient and soft ionization, which provides simpler mass-spectra than Atmospheric Pressure Chemical Ionization (APCI) mass spectrometer.

The PTR-TOF systems, which were later introduced, offered extra benefits for automotive exhaust monitoring:

• The measurement of complete spectra in < 1second
• Separation of isobaric molecules
• 对大分子的敏感性较高
• Identification of compounds by their chemical composition, and

设置

一般设置包括稀释系统，例如加热采样线和恒定体积采样器，以减少半挥发性化合物的表面相互作用。

在加利福尼亚空气资源委员会（CARB），Ionicon PTR-TOF 8000is employed in studies of automotive vehicle exhaust. As a primary step, Matsunaga et al. [1] validated the PTR-TOF system against a technique utilizing the gold standard, a GC-FID system (SOP MLD 102/103). The research revealed that measurements of BTEX vehicle emissions with the PTR-MS matched with GC-FID to within 15%.

柴油排气

在测功机测试中，使用车载诊断（OBD）信号来监视车辆参数。将OBD数据与PTR-MS的测量进行整合，包括乙醇，丙烯醛，甲醛，丙酮，苯乙烯，乙烯，乙烯，乙醛，乙醛，苯，二甲苯，1,3-丁二烯，甲苯，甲苯，甲苯，三甲基苯二苯和自中期研究。

汽油/汽油排气

Matsunaga等。^[1]also researched the emissions from gasoline vehicles and found that the VOC emissions from unburned fuel are very high at the beginning of a cold-start drive cycle but rapidly vanish as the vehicle warms up. The PTR-MS is unique with the ability to quantify a number of VOC species in real-time.

汽油/汽油和乙醇混合物

汽油经常与乙醇混合，例如E10（90％汽油中的乙醇10％），乙醇具有环境和经济考虑。乙醇/汽油比对排放的影响敏锐地研究了其他地方。为了进行此类分析，一种实时仪器PTR-MSserves as a robust tool for demonstrating the relationship between vehicle parameters and emissions.

参考

[1]Matsunaga et al. (February, 2015): Motor Vehicle Exhaust Analysis with a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) – Comparison Study with Conventional Methods for BTEX and Other Toxic Air Contaminants. Poster presented at CRC Mobile Source Air Toxics Workshop, Sacramento, CA, U.S.A.

此信息已从Ionicon Analytik提供的材料中采购，审查和改编。亚博网站下载

For more information on this source, please visitIonicon Analytik。