Research On Distributing Characteristics And Bioaccumulation Of Perfluoroalkyl And Polyfluoroalkyl Substances In Different Biological Matrixs

Perfluoroalkyl and polyfluoroalkyl substances(PFASs) are widely used in surfactants, additives and other industrial products because of their special physical and chemical properties. PFASs have been extensively detected in environment and organisms as the results of their widespread applications. In this study, we establish different analytical methods of PFASs according to characteristic of different matrix samples. We collected different samples in typically PFASs contaminated areas, such as vegetables irrigated by wastewater and fish with different feeding habits in Tangxun Lake. According to the profound analysis of pollution levels, distribution characteristics and bioconcentration of those samples, we can get the following conclusions:(1) Depending on the characteristics of the sample matrix, we establish and improve the pre-treatment methods and instrumental analysis methods by UPLC-ESI-MS/MS of PFASs including 17 perfluoro compound PFASs(13 perfluorinated carboxylic acids of C4-C18, 3 perfluorinated sulfonic acids and perfluorooctane sulfonamide FOSA) in various matrices including surface water, soil, vegetables, blood, bile and other tissues of fish, and eliminates the interference of matrix effects of bile acids on PFOS. According to the spiked recovery test of real samples, we find that the spiked recoveries and method detection limits can meet the basic requirements for the analysis of real samples.(2) Based on analysis results on the concentrations of PFASs in different types of vegetable samples(leafy vegetables and root vegetables) and the corresponding sampling sites of the irrigation water and the soil sample in Tangxun Lake with typical PFASs polluted area, it can be found that vegetables in the sewage irrigation area have been polluted in different degrees with the total pollution levels of PFASs in 4.16~807ng/g(dry weight), and it shows a positive correlation with the polluted degree in the surrounding environment. The results on bioaccumulation of PFASs in the vegetables show that PFASs can be absorbed by the soils in sewage irrigation, and then be absorbed by vegetables root, and then be transported to the leaves by transpiration. The short chain PFASs are more easily accumulated in vegetables, and accumulation ability decreases with the length of carbon chain increasing. The accumulation rules of PFASs are oppsite to that in the sample matrix with rich protein. Analysis of average daily intake of PFASs through intake of vegetables for the residents near Tangxun Lake show that an important source of the short chain PFASs in residents are intake of vegetables with sewage irrigation. It’s an important source of short chain PFASs in fisherman feeding sewage irrigation vegetables in Tangxun Lake by analyzing the average daily intake of the residents near Tangxun Lake.(3) By comparing the distribution, transformation and bioconcentration of PFASs in different organ compartments(muscle, blood, bile, liver and kidney) of herbivorous grass carp and filter-feeding silver carp in Tangxun Lake, we can find that the pollution level of PFASs in the tissues of grass carp is higher than that of silver carp except in bile. PFOS in grass carp and silver carp liver has the highest percentage of 88% and 81%, respectively, which indicates that PFOS may be reabsorbed by binding to in the transporter in the enterohepatic circulation of bile in the liver occur reabsorption. It can be found from the PFOS/FOSA in different tissues that PFOS/FOSA in all tissues of the grass carp is higher than that of silver carp corresponding to the tissues. And except in bile, PFOS/FOSA in liver is the highest. The reasons for that there are the most abundant P450 in liver, and the transformation rate of FOSA in liver is the fastest. So we can infer that thePFOS/ FOSA can be as biological markers to determine metabolic rate of PFASs. It can be found by analyzing the bioaccumulation of PFASs in different tissues that PFASs with long chain is more easily accumulated in the liver, blood and other tissues with rich protein.In conclusion, PFASs show different distribution characteristics in different matrices(surface water, soil, vegetables and fish tissues) due to a lot of factors. Except the particular physico-chemical properties(carbon chain length and functional groups), the PFASs transporters, enzyme participated in metabolism and the internal environment play an important role.