The relationship of chromophoric dissolved organic matter parallel factor analysis fluorescence and polycyclic aromatic hydrocarbons in natural surface waters

Abstract

Polycyclic aromatic hydrocarbons (PAHs), a large group of persistent organic pollutants (POPs), have caused wide environmental pollution and ecological effects. Chromophoric dissolved organic matter (CDOM), which consists of complex compounds, was seen as a proxy of water quality. An attempt was made to understand the relationships of CDOM absorption parameters and parallel factor analysis (PARAFAC) components with PAHs under seasonal variation in the riverine, reservoir, and urban waters of the Yinma River watershed in 2016. These different types of water bodies provided wide CDOM and PAHs concentration ranges with CDOM absorption coefficients at a wavelength of 350 nm (a (350)) of 1.17-20.74 m and total PAHs of 0-1829 ng/L. CDOM excitation-emission matrix (EEM) presented two fluorescent components, e.g., terrestrial humic-like (C1) and tryptophan-like (C2) were identified using PARAFAC. Tryptophan-like associated protein-like fluorescence often dominates the EEM signatures of sewage samples. Our finding is that seasonal CDOM EEM-PARAFAC and PAHs concentration showed consistent tendency indicated that PAHs were un-ignorable pollutants. However, the disparities in seasonal CDOM-PAH relationships relate to the similar sources of CDOM and PAHs, and the proportion of PAHs in CDOM. Overlooked and poorly appreciated, quantifying the relationship between CDOM and PAHs has important implications, because these results simplify ecological and health-based risk assessment of pollutants compared to the traditional chemical measurements.

The Human Health Assessment to Phthalate Acid Esters (PAEs) and Potential Probability Prediction by Chromophoric Dissolved Organic Matter EEM-FRI Fluorescence in Erlong Lake

“…The composition and distributions of CDOMs were impacted by the environmental factors (water quality, soil, vegetation, land use, and rainfall) and could generally affect the absorption and fluorescence of CDOMs at certain wavelengths [ 20 ]. Generally, the absorption coefficient a CDOM (350) is used to characterize the concentration of CDOMs [ 7 , 29 ] and a CDOM (254) can be used as a proxy for characterizing the aromaticity of CDOMs [ 7 , 30 ].…”

“…To determine the dissolved organic carbon (DOC) concentrations, all of the water samples were filtered through a pre-combusted Whatman GF/F (1825-047) filter (0.45 μm) under low vacuum and were measured by the Shimadzu TOC-VCPN analyzer. Chlorophyll a (Chl-a) was extracted from the filtered (0.45-µm Whatman GF/F) sample using a 90% acetone solution; subsequently, the concentrations were determined using a UV spectrophotometer (UV-2006 PC, Shimadzu, Kyoto, Japan); the detailed process can be found in Song et al (2012) [ 20 ]. The total suspended matter (TSM), inorganic suspended matter (ISM), and organic suspended matter (OSM) were determined by gravimetrical analysis.…”

“…The water samples were first filtered under low vacuum through a pre-combusted Whatman GF/F (1825-047) filter (0.7-µm pore size), and subsequently, through a pre-rinsed 25-mm diameter Millipore membrane cellulose filter (0.22-µm pore size) into brown glass bottles [ 6 ]. The Shimadzu UV-2600 spectrophotometer with 1-cm quartz cells between 200 nm and 800 nm at 1 nm increments with Milli-Q water as a reference was used to measure the twice-filtered water samples [ 20 ]. The CDOM absorption coefficient α CDOM ( ) was calculated from the measured optical density (OD), as follows: where γ is the cuvette path length (0.01 m) and 2.303 is the conversion factor.…”

“…The CDOM EEMs were obtained using the Hitachi F-7000 fluorescence spectrometer (Hitachi High-Technologies, Tokyo, Japan) with a 700-V xenon lamp as the light source [ 20 ]. The wavelength ranges of excitation were 220–450 nm at 5-nm sampling interval and 250–600 nm for the emission at a 1-nm sampling interval, with the scanning speed being maintained at 1200 nm/min.…”

The Effects of Different Natural Plant Extracts on the Formation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roast Duck

“…In recent years, various studies have found that PAHs in foods were mainly produced by high-temperature pyrolysis, gas combustion or direct contact with open fire (such as baking, grilling [ 8 ], drying [ 9 ] and smoking [ 10 ]), mainly due to the incomplete combustion of organic matter [ 11 , 12 , 13 ] or the high-temperature degradation of fat in barbecue products [ 14 ].…”