title: Application of a multi-method approach in characterization of natural aquatic colloids from different sources along Huangpu River in Shanghai, China.
abstract: Natural colloid properties and the impact of human activities on these properties are important considerations for studies seeking to understand the fate and transport of pollutants. In this study, the relationship between size and fluorescence properties of natural colloids from 4 different sources were quantified using a multi-method analytical approach including UV-visible and fluorescence spectroscopy, flow field flow fractionation (FlFFF) coupled online to fluorescence spectrometer, and atomic force microscopy (AFM). Results indicate that colloids from pristine natural river water have higher aromaticity and humification, higher fluorescent intensity, and smaller size compared to those from the rivers impacted by livestock. The majority of colloids are smaller than 10nm in size as measured by AFM and FlFFF. Colloid size measured by FlFFF coupled to fluorescence spectroscopy increases in the order peak C (Ex/Em at 300-340/400-460 nm)<peak D (Ex/Em at 210-230/340-360 nm)<peak T (Ex/Em at 270-280/330-370 nm)<peak A (Ex/Em at 210-250/400-460 nm), revealing that optical properties such as fluorescence are correlated with size. This trend is confirmed by the principal component analysis, which demonstrates that the first principal component (PC1) reflecting colloid optical properties decrease with the increase in PC3 which is correlated to the colloid size.
authors.affiliation: School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, 99 Ziyang Road, Nanchang 330022, China; Center for Environmental Nanoscience and Risk, Arnold School of Public Health, University of South Carolina, 921 Assembly Street, Columbia 29208, USA; State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Yan
authors.affiliation: School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, 99 Ziyang Road, Nanchang 330022, China.
authors.forename: Minghua
authors.initials: M
authors.lastname: Nie
authors.affiliation: Center for Environmental Nanoscience and Risk, Arnold School of Public Health, University of South Carolina, 921 Assembly Street, Columbia 29208, USA.
authors.forename: Jamie R
authors.initials: JR
authors.lastname: Lead
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China; Key Laboratory of Geographic Information Science of the Ministry of Education, Department of Geosciences, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Junliang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Center for Environmental Nanoscience and Risk, Arnold School of Public Health, University of South Carolina, 921 Assembly Street, Columbia 29208, USA.
authors.forename: Ruth
authors.initials: R
authors.lastname: Merrifield
authors.affiliation: Center for Environmental Nanoscience and Risk, Arnold School of Public Health, University of South Carolina, 921 Assembly Street, Columbia 29208, USA. Electronic address: MBAALOUS@mailbox.sc.edu.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Baalousha
mesh_terms: D002681:China; D003102:Colloids / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D031521:Fractionation, Field Flow; D006812:Humic Substances / Q000032:analysis; D018625:Microscopy, Atomic Force; D025341:Principal Component Analysis; D045483:Rivers / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D003102:Colloids; D006812:Humic Substances; D014874:Water Pollutants, Chemical
keywords: Absorbance; Colloids; Fluorescence; Principle component analysis (PCA); Size distribution