Ecotoxicology Program, Environmental Research Institute of the Supervising Scientist, GPO Box 461, Darwin, NT 0801, Australia.
Environ Sci Technol. 2011 Apr 1;45(7):3075-81. doi: 10.1021/es103330w. Epub 2011 Feb 25.
Fulvic acid (FA) from a tropical Australian billabong (lagoon) was isolated with XAD-8 resin and characterized using size exclusion chromatography, solid state cross-polarization magic angle spinning, 13C nuclear magnetic resonance spectroscopy, elemental analysis, and potentiometric acid-base titration. Physicochemical characteristics of the billabong FA were comparable with those of the Suwannee River Fulvic Acid (SRFA) standard. The greater negative charge density of the billabong FA suggested it contained protons that were more weakly bound than those of SRFA, with the potential for billabong water to complex less metal contaminants, such as uranium (U). This may subsequently influence the toxicity of metal contaminants to resident freshwater organisms. The complexation of U with dissolved organic carbon (DOC) (10 mg L(-1)) in billabong water was calculated using the HARPHRQ geochemical speciation model and also measured using flow field-flow fractionation combined with inductively coupled plasma mass-spectroscopy. Agreement between both methods was very good (within 4% as U-DOC). The results suggest that in billabong water at pH 6.0, containing an average DOC of 10 mg L(-1) and a U concentration of 90 μg L(-1), around 10% of U is complexed with DOC.
从澳大利亚热带泻湖（环礁湖）中分离出富里酸（FA），并用 XAD-8 树脂进行分离，并通过尺寸排阻色谱、固态交叉极化魔角旋转、13C 核磁共振波谱、元素分析和电位酸碱滴定进行了表征。泻湖 FA 的物理化学特性与苏万尼河富里酸（SRFA）标准相当。泻湖 FA 的负电荷密度更大，表明其含有比 SRFA 结合更弱的质子，因此泻湖水中可能会与较少的金属污染物（如铀（U））形成配合物。这可能会影响金属污染物对当地淡水生物的毒性。使用 HARPHRQ 地球化学形态模型计算了 U 与溶解有机碳（DOC）（10mgL(-1)）在泻湖水中的络合作用，并使用流场分离与电感耦合等离子体质谱相结合进行了测量。这两种方法之间的一致性非常好（在 U-DOC 范围内为 4%）。结果表明，在 pH 值为 6.0、DOC 平均浓度为 10mgL(-1)和 U 浓度为 90μgL(-1)的泻湖水中，约有 10%的 U 与 DOC 络合。
