title: Measurement of humic-like substances in aerosols: a review.
abstract: Aerosol-phase humic-like substances (HULIS) have received increasingly attention due to their universal ambient presence, active participation in atmospheric chemistry and important environmental and health effects. In last decade, intensive field works have promoted development of quantification and analysis method, unearthed spatio-temporal variation, and proved evidence for source identification of HULIS. These important developments were summarized in this review to provide a global perspective of HULIS. The diverse operational HULIS definitions were gradually focused onto several versions. Although found globally in Europe, Asia, Australasia and North America, HULIS are far more typical in continental and near-ground aerosols. HULIS concentrations varied from <1 μg/m(3) to >13 μg/m(3), with their carbon fraction making up 9%-72% of water soluble organic carbon. Dominant HULIS source was suggested as secondary processes and biomass burning, with the detailed formation pathways suggested and verified in laboratory works.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Guangjie
authors.initials: G
authors.lastname: Zheng
authors.forename: Kebin
authors.initials: K
authors.lastname: He
authors.forename: Fengkui
authors.initials: F
authors.lastname: Duan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cheng
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D018533:Biomass; D002244:Carbon; D004784:Environmental Monitoring; D005060:Europe; D006812:Humic Substances / Q000032:analysis*; D009656:North America; D014867:Water
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D006812:Humic Substances; D014867:Water; D002244:Carbon
keywords: Biomass burning; Heterogeneous reaction; Humic-like substances; Secondary formation pathways; Spatial–temporal variation