Harmonizing Aerosol Carbon Measurements between Two Conventional Thermal/Optical Analysis Methods

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• 作者：Guorui Zhi ; Yingjun Chen ; Junying Sun ; Laiguo Chen ; Wenjuan Tian ; Jingchun Duan ; Gan Zhang ; Fahe Chai ; Guoying Sheng ; Jiamo Fu
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：April 1, 2011
• 年：2011
• 卷：45
• 期：7
• 页码：2902-2908
• 全文大小：796K
• 年卷期：v.45,no.7(April 1, 2011)
• ISSN：1520-5851

文摘

Although total carbon (TC) can be consistently quantified by various aerosol carbon measurement methods, the demarcation of TC into organic carbon (OC) and elemental carbon (EC) has long been inconsistent. The NIOSH and IMPROVE protocols are most widely used for thermal/optical analysis (TOA), but current knowledge rests in the description that the NIOSH protocol usually gives lower EC values than does the IMPROVE protocol. This study seeks to explore the possibility of quantitatively linking the difference between the two TOA protocols. Residential coal-burning samples that had been collected and analyzed following the NIOSH protocol in previous studies were directly reanalyzed following the IMPROVE protocol for this study. A comparison of each pair of NIOSH and IMPROVE EC values reveals the dynamic relation between the two protocols, which can be expressed as a regression equation, y = (1鈭?i>x)/(1 + 4.86x²) (R² = 0.96), where the independent x is the EC/TC ratio (R_EC/TC) for the IMPROVE protocol, and the dependent y is the difference between IMPROVE and NIOSH R_EC/TC relative to IMPROVE R_EC/TC. This regression equation may be the first effort in formulating the relationship between the two TOA protocols, and it is very helpful in harmonizing inconsistent TOA measurements, for example, source characterization, ambient monitoring, and atmospheric modeling.