温度设置对热光法测定气溶胶中黑碳的影响  

Effects of Temperature Setting on Aerosol Black Carbon Measurement by Thermal-Optical Analysis

作　　者：支国瑞[1] 陈颖军[1] 熊胜春[2] 盛国英[1] 傅家谟[1] 

机构地区：[1]中国科学院广州地球化学研究所有机地球化学国家重点实验室 [2]上海大学环境与化学工程学院环境污染与健康研究所,上海200072

出　　处：《分析测试学报》2008年第4期381-385,共5页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(40605033,40590392);中国博士后科学基金资助项目(2005037597)

摘　　要：热光法中的无氧阶段最高温度(MT)和各温度阶梯的保持时间(HT)是测定大气气溶胶中黑碳的两个关键参数。该文采集了34个气溶胶样品(含20个大气样品和14个源排放样品),并设计了6个温度程序用以系统研究MT和HT对黑碳(BC)测定的影响。实验表明,提高MT的设置,会使BC测定值降低,最高温度为850℃时的BC值为550℃时的62%;而有机碳(OC)发生热解(碳化)与最高温度的关系没有固定的模式,这是由样品的化学成分不同造成的。增加保持时间,使BC的测定值下降约5%,使热解率下降10%。Black carbon（BC）, an important component of the atmospheric aerosol, plays a significant role in the climate change. Presently, the thermal -optical analysis （TOA） is widely used for the determination of BC, however, the BC data obtained varied with different settings of maximum temperature （MT） in pure He and the hold time （HT） in each step. In this paper, the effects of MT and HT on BC measurement by TOA were studied using 34 aerosol samples and six designed heating programs. Experimental results showed that the BC value would decrease with the increase of MT setting, e. g. the BC value obtained at a maximum temperature of 850 ℃ was 62% of that obtained at 550 ℃. The charring of organic carbon was not related to MT setting but varied with the chemical compositions of the samples. Prolonging the HT, the BC value and the charring decreased approximately by 5% and 10% , respectively.

关 键 词：黑碳 热光法 温度 气溶胶 

分 类 号：O648.18[理学—物理化学]