International Laboratory for Air Quality and Health, Queensland University of Technology , 2 George Street, Brisbane, Queensland 4001, Australia.
Environ Sci Technol. 2013 Jul 16;47(14):7655-62. doi: 10.1021/es4007433. Epub 2013 Jun 26.
Generally, the magnitude of pollutant emissions from diesel engines running on biodiesel fuel is ultimately coupled to the structure of the fuel's constituent molecules. Previous studies demonstrated the relationship between the organic fraction of particulate matter (PM) and its oxidative potential. Herein, emissions from a diesel engine running on different biofuels were analyzed in more detail to explore the role that different organic fractions play in the measured oxidative potential. In this work, a more detailed chemical analysis of biofuel PM was undertaken using a compact time of flight aerosol mass spectrometer (c-ToF AMS). This enabled a better identification of the different organic fractions that contribute to the overall measured oxidative potentials. The concentration of reactive oxygen species (ROS) was measured using a profluorescent nitroxide molecular probe 9-(1,1,3,3-tetramethylisoindolin-2-yloxyl-5-ethynyl)-10-(phenylethynyl)anthracene (BPEAnit). Therefore, the oxidative potential of the PM, measured through the ROS content, although proportional to the total organic content in certain cases, shows a much higher correlation with the oxygenated organic fraction as measured by the c-ToF AMS. This highlights the importance of knowing the surface chemistry of particles for assessing their health impacts. It also sheds light onto new aspects of particulate emissions that should be taken into account when establishing relevant metrics for assessing health implications of replacing diesel with alternative fuels.
一般来说，柴油机使用生物柴油燃料时污染物排放量的大小最终与燃料组成分子的结构有关。先前的研究表明了颗粒物（PM）的有机部分与其氧化潜力之间的关系。在此，通过更详细地分析柴油机在不同生物燃料下的排放，来探究不同有机部分在测量的氧化潜力中所起的作用。在这项工作中，使用紧凑型飞行时间气溶胶质谱仪（c-ToF AMS）对生物燃料 PM 进行了更详细的化学分析。这使得可以更好地识别出对整体测量的氧化潜力有贡献的不同有机部分。使用荧光氮氧自由基分子探针 9-（1,1,3,3-四甲基茚满-2-基氧基-5-乙炔基）-10-（苯乙炔基）蒽（BPEAnit）测量了活性氧物种（ROS）的浓度。因此，通过 ROS 含量测量的 PM 的氧化潜力，虽然在某些情况下与总有机含量成正比，但与 c-ToF AMS 测量的含氧有机部分的相关性要高得多。这突出表明了了解颗粒表面化学对于评估其健康影响的重要性。它还揭示了在建立替代柴油的替代燃料对健康影响的相关指标时应考虑的颗粒物排放的新方面。
