Grimes Courtney D, Conny Joseph M, Dickerson Russell R
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742.
Materials Measurement Science Division, National Institutes of Standards and Technology, Gaithersburg, Maryland, 20899.
Atmos Environ (1994). 2020 Nov 15;241. doi: 10.1016/j.atmosenv.2020.117647. Epub 2020 Jun 1.
Thermal-Optical Analysis (TOA), a commonly implemented technique used to measure the amount of particulate carbon in the atmosphere or deposited on a filter substrate, distinguishes organic carbon (OC) from elemental carbon (EC) through the monitoring of laser light, heating, and measuring evolved carbon. Here, we present a method to characterize the TOA transmission method with an aqueous binary mixture containing EC and OC that can easily be deposited onto a filter at low volumes. Known amounts of EC and OC were deposited onto a quartz-fiber filter and analyzed with different temperature protocols. Results with the NIST-EPA-C temperature protocol agreed with the reference values to better than 2 % for EC, OC, total carbon (TC), and EC/TC. Indicated TC for all temperature protocols was within 5 % of the reference value while all protocols reproduced EC/TC ratios with an uncertainty less than 10 %.
热光分析（TOA）是一种常用于测量大气中或沉积在滤膜基质上的颗粒碳含量的技术，它通过监测激光、加热和测量释放出的碳来区分有机碳（OC）和元素碳（EC）。在此，我们提出一种方法，用一种含有EC和OC的二元水性混合物来表征TOA传输方法，该混合物可以很容易地以低体积沉积在滤膜上。将已知量的EC和OC沉积在石英纤维滤膜上，并采用不同的温度方案进行分析。采用NIST-EPA-C温度方案得到的结果与参考值相比，EC、OC、总碳（TC）和EC/TC的误差优于2%。所有温度方案指示的TC在参考值的5%以内，而所有方案重现的EC/TC比率的不确定度小于10%。
