International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059, Australia.
Anal Chim Acta. 2013 Nov 25;803:91-6. doi: 10.1016/j.aca.2013.07.013. Epub 2013 Jul 9.
Aerosol Mass Spectrometers (AMS) are powerful tools in the analysis of the chemical composition of airborne particles, particularly organic aerosols which are gaining increasing attention. However, the advantages of AMS in providing on-line data can be outweighed by the difficulties involved in its use in field measurements at multiple sites. In contrast to the on-line measurement by AMS, a method which involves sample collection on filters followed by subsequent analysis by AMS could significantly broaden the scope of AMS application. We report the application of such an approach to field studies at multiple sites. An AMS was deployed at 5 urban schools to determine the sources of the organic aerosols at the schools directly. PM1 aerosols were also collected on filters at these and 20 other urban schools. The filters were extracted with water and the extract run through a nebulizer to generate the aerosols, which were analyzed by an AMS. The mass spectra from the samples collected on filters at the 5 schools were found to have excellent correlations with those obtained directly by AMS, with r(2) ranging from 0.89 to 0.98. Filter recoveries varied between the schools from 40 to 115%, possibly indicating that this method provides qualitative rather than quantitative information. The stability of the organic aerosols on Teflon filters was demonstrated by analysing samples stored for up to two years. Application of the procedure to the remaining 20 schools showed that secondary organic aerosols were the main source of aerosols at the majority of the schools. Overall, this procedure provides accurate representation of the mass spectra of ambient organic aerosols and could facilitate rapid data acquisition at multiple sites where AMS could not be deployed for logistical reasons.
气溶胶质谱仪（AMS）是分析空气中颗粒物化学组成的有力工具，特别是越来越受到关注的有机气溶胶。然而，AMS 在提供在线数据方面的优势可能因在多个地点进行现场测量时所涉及的困难而被抵消。与 AMS 的在线测量相比，涉及在过滤器上收集样品，然后通过 AMS 进行后续分析的方法可以显著拓宽 AMS 的应用范围。我们报告了在多个地点的实地研究中应用这种方法的情况。在 5 所城市学校部署了一台 AMS，以直接确定学校内有机气溶胶的来源。还在这些学校和其他 20 所城市学校的过滤器上收集了 PM1 气溶胶。用滤器提取水，并将提取物通过喷雾器生成气溶胶，然后用 AMS 进行分析。在 5 所学校收集的过滤器上采集的样品的质谱与直接通过 AMS 获得的质谱具有极好的相关性，相关系数 r（2）范围从 0.89 到 0.98。学校之间的过滤器回收率从 40%到 115%不等，这可能表明该方法提供的是定性信息，而不是定量信息。通过分析储存长达两年的样品，证明了 Teflon 滤器上有机气溶胶的稳定性。将该程序应用于其余 20 所学校表明，二次有机气溶胶是大多数学校气溶胶的主要来源。总的来说，该程序提供了环境有机气溶胶质谱的准确表示，并且可以在由于后勤原因无法部署 AMS 的多个地点方便快速地获取数据。
