摘要
将气体-气溶胶收集仪(GAC)与一台湿法测量总有机碳(Total Organic Carbon,TOC)值的TOC分析仪连接,开发了一套在线测量细粒子中水溶性有机碳(Water Soluble Organic Carbon,WSOC)的方法,解决了方法建立初期背景值较高的问题,确立了方法运行的条件,分析了造成方法测量不确定性的原因,并将其用于珠江三角洲地区20d的连续观测(3C-STAR).GAC-TOC在线测量WSOC的方法检测限为0.07μg.m-3,它能提供离线采样方法不能达到的高时间分辨率;将该方法所测WSOC浓度与热解法元素碳/有机碳(Elemental Carbon/Organic Carbon,EC/OC)分析仪所测得OC浓度进行了比对,结果显示出较好的相关性,证明了其采样的准确性和可靠性.整个观测期间WSOC平均值为(2.81±2.31)μg.m-3,占OC的比例的平均值为23%±13%,最高小时均值为77%;WSOC和OC显示了较为一致的日变化规律.观测结果表明,GAC-TOC在线测定WSOC的方法可连续实时的得到大气颗粒物中WSOC浓度.
A new method for on-line measurements of water-soluble organic compounds （WSOC） was developed by coupling a gas-aerosol collector （GAC） with a total organic carbon （TOC） analyzer. A few modifications were made to solve the problem of high blank TOC of the system. The detection limit of the method is 0.07μg·m-3. The method was applied for continuous measurement of WSOC at a super-site in the Kaiping rural area for 20 days and the causes for the uncertainties of the method were analyzed. Comparison of the results of WSOC concentration measured by the new method and OC concentration measured by a Sunset EC/OC analyzer showed good correlation,which suggests the accuracy of the method. The average concentration of WSOC was （2.81±2.31）μg·m-3 and accounted for 23%±13% of OC concentration in PM2.5 during the campaign. The diurnal variations of WSOC and OC showed similar patterns. The results of the field campaign proved the method is useful as a real-time measurement for WSOC.
出处
《环境科学学报》
CAS
CSCD
北大核心
2010年第5期908-914,共7页
Acta Scientiae Circumstantiae
基金
国家高技术研究发展计划(863)项目(No.2006AA06A301
2006AA06A308
2006AA06A307)~~
