摘要
单颗粒气溶胶质谱仪能够实时快速分析单个颗粒物的大小及化学组成,不需要对样品进行任何的前处理,避免了样品组分的变化。本研究利用自制单颗粒气溶胶质谱仪对柴油车排放颗粒物的单颗粒特征进行了分析。一方面分析了柴油车直接排放的新鲜颗粒物的特征,另一方面将新鲜排放的颗粒收集在抽滤瓶中,让其在大气中经历15 h老化之后再次进行检测。实验表明,新鲜排放的颗粒粒径主要集中在300 nm以下,主要为元素碳(EC)、有机碳(OC)、钙磷酸盐(Ca-Phosphate)、钠钾及元素碳混合(NaK-EC)、钾二次离子混合(K-Secondary)以及多环芳烃颗粒(PAH)。老化之后的颗粒粒径分布较新排放的颗粒粒径明显增加,主要为有机碳元素碳二次种类的混合(OCEC-Secondary)、仅含有正离子的元素碳、K-Secondary、OC、NaK-EC、含金属离子(Metal)。老化之后颗粒物结合了大量有机物及硝酸盐、硫酸盐、铵盐等二次离子。这一研究结果对国内的发动机制造、油品加工、催化剂性能研究以及环境颗粒物源解析等工作具有一定的参考意义。
Single particle mass spectrometer （SPAMS） can be used to determine the size and chemical compositions of single particles rapidly in real-time, while no need for sample pretreatment and avoiding the change of the sample components. In this study, homemade SPAMS was used to study the signatures of diesel exhaust particles. The fresh emitted particles were analyzed firstly. The fresh particles collected in the suction flask were then reanalyzed after 15-hour aging. Results showed that fresh emitted particles were mainly composed by elemental carbon （ EC ）, organic carbon （ OC ）, calcium phosphate （ Ca-Phosphate）, sodium and potassium mixing with elemental carbon （ NaK-EC ）, potassium mixing with secondary （K-Secondary） and polycyclic aromatic hydrocarbons （PAH）, with diameters concentrating in less than 300 nm. Aged particles had a broader size distribution than that of fresh particles and were composed by EC and OC mixing with secondary species （OCEC-Secondary）, EC containing only positive mass spectra, K-Secondary, OC, NaK-EC, metal containing （Metal） particles. Aged particles mix with secondary species including organics, nitrate, sulfate, ammonium in the atmosphere. This study has reference sense for domestic engine manufacture, oil processing, catalyst performance study and environmental particles apportionment.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2013年第12期1831-1836,共6页
Chinese Journal of Analytical Chemistry
基金
上海高校教师产学研践习计划(No.B.60-B111-12-001)
中国科学院战略性先导科技专项(No.XDB05040502)的支持
关键词
质谱
柴油车排放
单颗粒
粒径与成分
Mass spectrometry
Diesel exhaust
Single particle
Size and composition
作者简介
E—mail：limei2007@163．com
