Two hundred and twenty five PM2.5 samples were collected in four seasons at three sites in Jinhua,and were analyzed with gas chromatography/mass spectrometry (GC/MS).Ten polar organic tracers were identified and quantified,including five tracers of secondary organic aerosols (SOA),i.e.three for isoprene,one for α-pinene and one for toluene,and five tracers of primary organic aerosols (POA),i.e.two for fungal spores and three for biomass burning.The concentrations of the SOA tracers for isoprene,α-pinene and toluene were 3.41 ～ 48.50,2.45～ 25.40 and 4.75 ～ 39.80 ng·m 3,respectively.Seasonal variations of concentrations of isoprene SOA tracers for isoprene and α-pinene were summer ＞autumn ≈ spring ＞ winter,while autumn ＞ summer ＞ spring ＞ winter for the toluene SOA tracer.It was estimated that 3.03％ ～ 24.50％ of OC was contributed by SOA from toluene and 1.23％ ～42.80％ of OC was from biomass burning,indicating that SOA from anthropogenic emissions and biomass burning were two important sources of fine particles in Jinhua.

Organosulfates which have been discovered in secondary organic aerosols are important constituents of PM2.5 in the atmosphere. Formed through anthropogenic activities and biogenic emissions, they have negative impacts on not only human health but also global climate change. Based on major precursors in different atmospheric environments, i.e., biogenic volatile organic compounds isoprene and alpha-/beta-pinene in forest (clean area), anthropogenic polycyclic aromatic hydrocarbons in urban (polluted area), and biogenic and anthropogenic mixed sources carbonyls in areas affected by both vegetation and human activities, we elaborated systematically the categories and structures of organosulfates and their photooxidation formation pathway under various atmospheric conditions with different atmospheric oxidants in the presence of SO2/H2SO4. Then, relevant literatures have been reviewed as much as possible and the concentration levels in PM2.5 in reported areas worldwide aresummarized. Moreover, up-to-date analytical techniques are described, as well as their benefits and drawbacks. Finally, impact factors of organosulfates formation are discussed. At the end of context, several issues are proposed which need to be addressed urgently, and future research directions in organosulfates are also prospected.

运用气相色谱/质谱(gas chromatography-mass spectrometry,GC/MS)对浙江一中学夏季PM2.5样品进行了分析,研究了各二次有机气溶胶(secondary organic aerosol,SOA)示踪物的浓度水平及SOA形成的影响因素,并利用示踪物产率法分析了二次有机碳(secondary organic carbon,soc)对有机碳(organic carbon,oc)的贡献.结果表明:异戊二烯SOA示踪物在总SOA示踪物浓度中所占比重较大,达到31.3％～52.2％,其中2.甲基甘油酸是主要的异戊二烯SOA示踪物;而α-蒎烯SOA示踪物所占比重最小,仅占总SOA示踪物浓度的16.4％～35.8％.甲苯SOA示踪物的浓度范围为6.49～12.60 ng/m3,高于上海宝山和中国香港地区,低于北京和广州地区.甲苯SOC对OC的贡献率为11.5％～17.7％,是SOC的重要组成部分,表明人为源排放是当地大气污染的重要来源.另外,各示踪物浓度以及总SOC浓度都与O3浓度呈显著正相关,表明O3对SOC的形成具有重要影响.

Biomass burning is an important source of carbonaceous aerosols in atmosphere. Water?soluble potassium ion ( K+ ) , monosaccharide anhydrides ( levoglucosan, mannosan and galactosan) , dehydroabietic acid are considered primary tracers of biomass burning emissions. Among them, monosaccharide anhydrides, which are not only abundant but also chemically stable during photooxidation in the air, are widely used as chemical markers in the assessment of biomass burning contribution to atmospheric aerosols. It has been reported that the levoglucosan level has seasonal variations. Furthermore, the chemical compositions of isomeric monosaccharide anhydrides show characteristic features depending on the combustion materials, which could be useful in the determination of the type of biomass burnt. For example, the ratio of levoglucosan to mannosan from soft wood is about 4. 3, whereas for hard wood it is around 23. 1 and for agricultural residue 32. 0. GC?MS is a robust analytical technique in detecting many organic compounds, though a complex pretreatment may be required. On the other hand, HPLC?MS and HPAEC?PAD methods do not demand pre?derivation and can measure liquid samples directly. In practice, one has to choose what is feasible for the sample.