It has recently been proposed that recalcitrant dissolved organic carbon(DOC) in groundwater plays a potent etiological role in the peculiar distribution of chronic kidney disease of unknown etiology(CKDu).This study ...It has recently been proposed that recalcitrant dissolved organic carbon(DOC) in groundwater plays a potent etiological role in the peculiar distribution of chronic kidney disease of unknown etiology(CKDu).This study aims to elucidate the interactions of Ca^2+and SO4^2-with a model organic fraction of humic acid(SHA) to determine the possible relationship of CKDu incidence with the DOC in drinking water.XPS and FT-IR methods respectively determined the surface functional groups and chemical composition of protonated dissolved organic carbon(HDOC) in a CKDu high-risk zone(HR) of Sri Lanka and in SHA.Higher surface C composition(87.9%) and lower O(11.4%) were observed for HDOC from the HR region than for SHA(C: 73.8%, O: 24.7%).Aromatic C with less Ocontaining functional groups was observed in HDOC.The IR band at 1170 cm^-1 confirms the formation of organic sulfonate(C–SO3^-) on SHA.A band at 1213 cm^-1 due to organic sulfonate in HDOC from the CKDu HR region was also identified.The IR band at 866 cm^-1 evidenced the formation of CaCO3 on SHA above pH 7.4.XPS data confirmed the presence of sulfur oxidation states corresponding to SO3^2-and SO4^2-at 168.9 eV and 170.1 eV binding energies,respectively.The binding energies at 347 eV and 351 eV for Ca 2p3/2 and Ca 2p1/2 eV,respectively, confirmed the bidentate complexation of Ca^2+with COO-and sulfonate groups on SHA.The organic sulfonate formed is postulated as a uremic toxicant.展开更多
目的优选海带褐藻糖胶(FPS)磺化的工艺。方法以氯磺酸-N,N-二甲基甲酰胺(DMF)为磺化试剂,采用正交设计法,考察反应时间、反应温度及磺化剂用量对海带褐藻糖胶磺化反应的影响,找出制备高硫酸根含量海带褐藻糖胶的最佳方法。结果反应时间...目的优选海带褐藻糖胶(FPS)磺化的工艺。方法以氯磺酸-N,N-二甲基甲酰胺(DMF)为磺化试剂,采用正交设计法,考察反应时间、反应温度及磺化剂用量对海带褐藻糖胶磺化反应的影响,找出制备高硫酸根含量海带褐藻糖胶的最佳方法。结果反应时间和反应温度对海带褐藻糖胶的磺化有显著影响(0.01<P<0.05),磺化剂用量对海带褐藻糖胶的磺化有一定影响(0.05<P<0.1)。实验得到的海带褐藻糖胶的最佳磺化工艺为:反应时间3 h,反应温度50℃,磺化剂用量25 m l。结论用SO3-DMF作为磺化试剂对海带褐藻糖胶进行磺化是可行的,可避免使用毒性较强的SO3-吡啶作为磺化试剂,方法简单,可用于制备保健品和药品。展开更多
基金国家海洋公益性行业科研专项(201005024)国家自然科学基金中俄(NSFC-RFBR)国际合作交流项目(81311120092)the Russian Foundation for Basic Research(grant 13-03-91170 within the bilateral grant program between RFBR and NSFC)资助
基金supported by the Joint Research Program of National Natural Science Foundation, ChinaNational Science Foundation, Sri Lanka (NSFC-NSF SL) (No.21861142020)+1 种基金the Program of China–Sri Lanka Joint Research and Demonstration Center for Water Technology and China– Sri Lanka Joint Center for Education and Research by Chinese Academy of Sciences, Chinathe Chinese Academy of Sciences–The World Academy of Sciences (CAS–TWAS) President’s Fellowship Program for International Ph.D.students.
文摘It has recently been proposed that recalcitrant dissolved organic carbon(DOC) in groundwater plays a potent etiological role in the peculiar distribution of chronic kidney disease of unknown etiology(CKDu).This study aims to elucidate the interactions of Ca^2+and SO4^2-with a model organic fraction of humic acid(SHA) to determine the possible relationship of CKDu incidence with the DOC in drinking water.XPS and FT-IR methods respectively determined the surface functional groups and chemical composition of protonated dissolved organic carbon(HDOC) in a CKDu high-risk zone(HR) of Sri Lanka and in SHA.Higher surface C composition(87.9%) and lower O(11.4%) were observed for HDOC from the HR region than for SHA(C: 73.8%, O: 24.7%).Aromatic C with less Ocontaining functional groups was observed in HDOC.The IR band at 1170 cm^-1 confirms the formation of organic sulfonate(C–SO3^-) on SHA.A band at 1213 cm^-1 due to organic sulfonate in HDOC from the CKDu HR region was also identified.The IR band at 866 cm^-1 evidenced the formation of CaCO3 on SHA above pH 7.4.XPS data confirmed the presence of sulfur oxidation states corresponding to SO3^2-and SO4^2-at 168.9 eV and 170.1 eV binding energies,respectively.The binding energies at 347 eV and 351 eV for Ca 2p3/2 and Ca 2p1/2 eV,respectively, confirmed the bidentate complexation of Ca^2+with COO-and sulfonate groups on SHA.The organic sulfonate formed is postulated as a uremic toxicant.
文摘目的优选海带褐藻糖胶(FPS)磺化的工艺。方法以氯磺酸-N,N-二甲基甲酰胺(DMF)为磺化试剂,采用正交设计法,考察反应时间、反应温度及磺化剂用量对海带褐藻糖胶磺化反应的影响,找出制备高硫酸根含量海带褐藻糖胶的最佳方法。结果反应时间和反应温度对海带褐藻糖胶的磺化有显著影响(0.01<P<0.05),磺化剂用量对海带褐藻糖胶的磺化有一定影响(0.05<P<0.1)。实验得到的海带褐藻糖胶的最佳磺化工艺为:反应时间3 h,反应温度50℃,磺化剂用量25 m l。结论用SO3-DMF作为磺化试剂对海带褐藻糖胶进行磺化是可行的,可避免使用毒性较强的SO3-吡啶作为磺化试剂,方法简单,可用于制备保健品和药品。
