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Objective: This study aimed to improve the technological conditions of antioxidant activity of pumpkin polysaccharide. Methods: The effects of temperature, pumpkin powder/distilled water ratio of solid to liquid, inoculation amount and shaking speed on the extraction rate of bio-transformed pumpkin polysaccharide were investigated, and the scavenging ability of pumpkin polysaccharide on DPPH free radical was studied. Results: The optimal conditions were inoculation amount 1% and solid-liquid ratio 1∶30 (g/mL), with shaking speed of 100 r/min at 37 ℃. Under the control of these conditions, the scavenging rate of DPPH free radical was （54.61±1.58）%. The in vitro antioxidant activity of the bio-transformed pumpkin polysaccharide was significantly higher than that of the non-transformed one. Conclusion: Lactobacillus plantarum nbkBC299 could improve the antioxidant activity of pumpkin polysaccharide.

Hexa (imidazolyl) cyclotriphosphazene (HImCP) was synthesized by nucleophilic substitution reaction of hexachlorocyclotriphosphazene with imidazole. The chemical structure was characterized by FT-IR,1H-NMR, and 31P-NMR. Then the as-prepared HImCP was utilized as curing catalyst for curing of diglycidylether of bisphenol A(E51)with methylhexahydrophthalic anhydride(MHHPA). Its influence on the storage stability at room temperature and curing activity at high temperature of E51/MHHPA system was studied by gelatum time and non-isothermal DSC analysis. The mechanical performance,glass-transition temperature(Tg),and thermostability of the obtained epoxy thermosets were also investigated. The results show that HImCP is a good latent curing catalyst contrast with unmodified imidazole. When the epoxy resin curing system contains 1% (mass fraction) of HImCP,it exhibits improved storage stability at room temperature as compared to that containing imidazole,as well as satisfied curing activity at high temperature. In addition,the obtained thermoset has higher tensile strength,Tg and thermostability than that resulted from imidazole.

QuEChERS method, Accelerated Solvent Extraction(ASE) and Ultrasound Extraction(UE) were used for sample extraction and are reported in this paper. Combined with liquid chromatograph coupled with mass spectrometry, these extraction methods were used to determine eighteen kinds of trace carbamate and triazole pesticides in soil with strong polarity and poor thermal stability. Results show that the standard addition recoveries of the QuEChERS method range from 76.3% to 121.0% with the exception of aldicarb(27.5%), whereas those of UE ranged from 71.0% to 100.0% with the exception of aldicarb(4.7%) and aldicarb sulfoxide(137.8%). The recoveries of ASE are mostly below 70%, but methiocarb, aldicarb and triadimenol are almost not recovered. Therefore, the QuEChERS method was eventually chosen as the sample extraction method for determining carbamate and triazole pesticides. The low recovery of aldicarb and high recovery of aldicarb sulfoxide were related to the heating effect of the extraction method, whereas the recoveries of fenobucarb and carbaryl were related to soil types.

At present, little research on perfluorinated compounds (PFCs) has been carried out in rural areas. To better determine the pollution level and the geographical distribution of PFC in rural areas, soils, surface waters, and groundwaters were collected from 8 rural areas in eastern China. Seventeen PFC compounds were analyzed using Solid Phase Extraction (SPE) and LC-MS-MS. The sources of PFCs are determined by compound ratios. Results show that PFOA (0.34-14.5 ng/g) is the dominant perfluorinated carboxylic acids (PFCAs) and PFOS (0.02-0.08 ng/g) is the dominant perfluoroalkane sulfonates (PFSAs) in the soils. PFCs in surface water are mainly PFOA (4.8-29.6 ng/L), PFHxA (0.73-31.8 ng/L), PFOS (nd-7.1 ng/L), and PFBA (nd-6.1 ng/L). PFOA (nd-176 ng/L), PFHxA (nd-50.1 ng/L), and PFBA (0.08-16.1 ng/L) are the dominant PFCs in groundwater. PFCs in soil and groundwater decrease from south to north. Two main sources of PFCs are domestic sewer and atmospheric precipitations, of which atmospheric precipitations have a greater contribution.