...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemical speciation and bioavailability >Determination of total lead and lead species according to their lability in coastal seawater by Chelex-100 titration and electrothermal-atomic absorption spectrometry
【24h】

Determination of total lead and lead species according to their lability in coastal seawater by Chelex-100 titration and electrothermal-atomic absorption spectrometry

机译：Chelex-100滴定和电热原子吸收光谱法测定沿海海水中铅和铅的总含量

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A speciation method based on Chelex-100 titration in combination with electrothermal-atomic absorption spectrometry has been developed to study the distribution of Pb among different fractions in coastal seawater. The method allows an accurate determination of total Pb, thereby avoiding the effect of the saline matrix. Additionally, the distribution patterns of Pb among species with different lability can be established in seawater as a function of pH. Four Pb fractions have been obtained in a model seawater and two seawater samples from Ria de Vigo (NE Atlantic ocean), i.e. free Pb ion, inorganic Pb fraction, organic Pb fraction and inert Pb fraction. The inert and labile organic Pb fractions dominate at natural pH (≈8). Complexation mechanisms of Pb were investigated from the sorption curves of lead on Chelex-100 according to the Gibbs–Donnan model. Three complexes were formed, PbL, PbL_2 and Pb(HL)_2 with the following intrinsic complexation constants logβ(1np)=-3.25, -10.10 and -1.98, respectively. The formation of the complex PbL is negligible in all range of pH studied, while the complex Pb(HL)_2 predominates up to pH 4 and PbL_2 from pH 4.
机译：开发了一种基于Chelex-100滴定结合电热原子吸收光谱法的形态分析方法，以研究沿海海水中不同部分之间铅的分布。该方法可以准确测定总Pb，从而避免了盐水基质的影响。另外，可以建立海水中随pH变化的铅在具有不同不稳定性的物种之间的分布模式。在模型海水中和从Ria de Vigo（东北大西洋）的两个海水样品中获得了四个Pb馏分，即游离Pb离子，无机Pb馏分，有机Pb馏分和惰性Pb馏分。惰性和不稳定的有机Pb组分在自然pH值（≈8）时占主导地位。根据Gibbs–Donnan模型，从Chelex-100上铅的吸附曲线研究了Pb的络合机理。形成了三种复合物，PbL，PbL_2和Pb（HL）_2，其固有的络合常数分别为logβ（1np）=-3.25，-10.10和-1.98。在研究的所有pH范围内，复合物PbL的形成都可以忽略不计，而复合物Pb（HL）_2占主导地位，直到pH 4为止，而从pH 4开始则为PbL_2。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号