Kraal Peter, Jansen Boris, Nierop Klaas G J, Verstraten Jacobus M
Institute for Biodiversity and Ecosystem Dynamics - Earth Surface Processes and Materials (IBED-ESPM), Universiteit van Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
Chemosphere. 2006 Dec;65(11):2193-8. doi: 10.1016/j.chemosphere.2006.05.058. Epub 2006 Jul 11.
The speciation of titrated copper in a dissolved tannic acid (TA) solution with an initial concentration of 4 mmol organic carbon (OC)/l was investigated in a nine-step titration experiment (Cu/OC molar ratio=0.0030-0.0567). We differentiated between soluble and insoluble Cu species by 0.45 microm filtration. Measurements with a copper ion selective electrode (ISE) and diffusive gradients in thin films (DGT) were conducted to quantify unbound Cu(II) cations ("free" Cu) and labile soluble Cu complexes. For the DGT measurements, we used an APA hydrogel and a Chelex 100 chelating resin (Na form). Insoluble organic Cu complexes (>0.45 microm) was the dominant Cu species for Cu/OC=0.0030-0.0567 with a maximum fraction of 0.96 of total Cu. At Cu/OC>0.0100, Cu-catalysed degradation of aggregate structures resulted in a strong increase of free Cu and (labile) soluble Cu complexes with a maximum fraction of 0.28 and 0.32 of total Cu, respectively. Labile (i.e. DGT-detectable) soluble Cu complexes had a relatively high averaged diffusion coefficient (D) in the APA hydrogel (3.50 x 10(-6)- 5.58 x 10(-6)cm(2)s(-1)).
在一个九步滴定实验（铜/有机碳摩尔比 = 0.0030 - 0.0567）中，研究了初始浓度为4 mmol有机碳（OC）/升的溶解单宁酸（TA）溶液中滴定铜的形态。我们通过0.45微米过滤区分可溶和不溶的铜形态。使用铜离子选择性电极（ISE）和薄膜扩散梯度（DGT）进行测量，以量化未结合的铜（II）阳离子（“游离”铜）和不稳定的可溶性铜络合物。对于DGT测量，我们使用了APA水凝胶和Chelex 100螯合树脂（钠型）。对于铜/有机碳 = 0.0030 - 0.0567，不溶性有机铜络合物（> 0.45微米）是主要的铜形态，占总铜的最大比例为0.96。当铜/有机碳> 0.0100时，铜催化的聚集体结构降解导致游离铜和（不稳定的）可溶性铜络合物大幅增加，分别占总铜的最大比例为0.28和0.32。不稳定的（即可被DGT检测到的）可溶性铜络合物在APA水凝胶中的平均扩散系数（D）相对较高（3.50×10⁻⁶ - 5.58×10⁻⁶ cm² s⁻¹）。
Zotero 插件