| 洞庭湖沉积物腐殖酸的配位性与酸碱性研究 |
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| 引用本文： | 曾蕾,易诚,周崇文,陈科.洞庭湖沉积物腐殖酸的配位性与酸碱性研究[J].火山地质与矿产,2010(2):136-143. |
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| 作者姓名： | 曾蕾 易诚 周崇文 陈科 |
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| 作者单位： | 湖南环境生物学院,湖南衡阳421005 |
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| 基金项目： | 国土资源部科技司自由选题项目（编号992008）资助. |
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| 摘 要： | 通过电位滴定研究了从洞庭湖沉积物中分离得到的腐殖酸（HA）的酸碱性和配位性，采用修正格兰函数进行了数据拟合。表征了六类可滴官能团含量和分布，pKa数值在2．35～10．50之间，羧基占可电离中心总数的62％，利用铜离子选择电极和汞齐电极（Pb、Cd和Zn）研究了腐殖酸与Cu^2＋、Pb^2＋、Cd^2＋和Zn^2＋配位性质，借助Scatchard方法对数据进行了处理，显示铜和铅为二配体，镉和锌为单配体。平均稳定常数顺序为：logKHA-Pb〉logKHA-Cd〉logKHAtZn，配位能力顺序为：Pb〉Cu〉Cd≈Zn。
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| 关 键 词： | 腐殖酸 酸碱滴定 配位能力 稳定常数 |
Study on coordination properties and acidity-basicity of humic acids extracted from sediments of Dongting Lake |
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| ZENG Lei,YI Cheng,ZHOU Cong-wen,CHEN Ke.Study on coordination properties and acidity-basicity of humic acids extracted from sediments of Dongting Lake[J].Volcanology & Mineral Resources,2010(2):136-143. |
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| Authors: | ZENG Lei YI Cheng ZHOU Cong-wen CHEN Ke |
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| Institution: | (Hunan Environment ＆ Biologic Polytechnic, Hengyang 421005, China) |
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| Abstract: | The acidity-basicity and coordination property of humic acids isolated from sediments of Dongting Lake by using of potentiometric titration method and the data fitting by using of modified Gran function are studied. The contents and distribution of six classes of titratable groups are characterized, the pKa values are varied between 2.35-10. 50, the carboxyl groups are accounted for 66 % of total ionizable sites. The coordination properties of humic acids with Cu^2＋, Pb^2＋, Cd^2＋ and Zn^2＋ by using of Cu-ion selective electrode or amalgam electrode （Pb, Cd and Zn） are discussed. The data treatment by the Scatchard method reveals a double coordination for copper and lead and a single coordination for cadmium and zinc. The average stability constants are in the following order：logKHA-Pb〉logKHA-Cd〉logKHAtZn,while the coordination capacity order is： Pb〉 Cu〉 Cd≈gZn. |
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| Keywords: | humic acid acid-base titrimetry coordination properties stability constants |
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