Abstract：
Aquatic nano particles (1nm-100nm) or colloids comprise macromolecular organic materials, such as humic and fulvic acids, proteins, and peptides, as well as colloidal inorganic species, typically hydrous iron and manganese oxides. Their small size and large surface area per unit mass make them important binding phases for both organic and inorganic contaminants. They play a central role inregulating the concentration, mobility, toxicity and bioavailability of many contaminants in aquatic ecosystems. However knowledge concerning the size distribution of aquatic natural nano particles and its impact on contaminant fate is limited. In this study, flow field-flow fractionation coupled with on-line UV/Visible and three-dimensional fluorescence detectors was used to investigate the relationship between molecular weight distribution and the optical properties of natural organic namo materials. The results were analyzed using parallel factor analysis (PARAFAC) and statistical fractogramde convolution to correlate fluorescing components with molecular weight fractions. This coupling, which is shown for the first time in this work, is a powerful method capable of revealing novel information about the size properties of PARAFAC components in natural nano particles.
