The speciation of lead in seawater by pseudopolarography using a vibrating silver amalgam microwire electrode
The speciation of lead in seawater by pseudopolarography using a vibrating silver amalgam microwire electrode
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使用振动银汞齐微线电极通过伪极谱法分析海水中铅的形态
DOI：
10.1016/j.marchem.2013.02.003
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发表时间：
2013
期刊：
影响因子：
3
通讯作者：
Bi Z
中科院分区：
文献类型：
--
作者：
Bi Z
将一种基于振动银汞齐微丝的新型电极用于海水中铅的伪极谱测定。伪极谱法是一种通过检测金属物种的还原电位来研究其稳定性的方法。动力学不可逆物种的还原电位与热力学复合稳定常数有关，而不稳定物种的还原电位与条件稳定常数有关。这种新电极能够在未受污染的海水中以皮摩尔水平对铅进行形态分析。电化学不可逆铅配合物的电位漂移校准对几个配体在pH 8的海水中的复杂的稳定性。该方法进行了比较，对汞滴电极在不同浓度的铅和不同的沉积时间，和响应与理论大体一致。该方法是测试样品从海洋（大西洋），沿海（爱尔兰海）和河口（默西）的起源在铅浓度在30 pM和2 nM之间。假极谱图被发现解决的不稳定和不可逆的结合铅物种的铅的形态。样品中的铅大部分在伪极谱图的不稳定组分中，表明它与海洋样品的log α′ Pb 2 + L值为2，沿海样品的log α′ Pb 2 + L值为4可逆络合。较小的部分被解析为稳定的、不可逆结合的物质，其热力学稳定性常数的值为log KPb 2 +L=15-16。的形态的方法是能够解决的金属物种发生的水平只有一小部分的金属。不像铜，其中有机络合是强的和电化学不可逆的，并能够显着降低其生物利用度，铅主要发生在不稳定的络合部分，因此很容易为地球化学清除或生物吸收反应。
A novel electrode based on a vibrating silver amalgam microwire was used for pseudopolarography of lead (Pb) in seawater. Pseudopolarography is a method to study the stability of metal species by examination of their reduction potential. The reduction potential of kinetically irreversible species is related to the thermodynamic complex stability constant, whilst for labile species it is related to the conditional stability constant. The new electrode enables the speciation of Pb at picomolar level in uncontaminated seawater. The potential shift of electrochemically irreversible lead complexes was calibrated against the complex stability of several ligands in pH8 seawater. The method was compared against the mercury drop electrode at various concentrations of lead and various deposition times, and the response was in general agreement with the theory. The method is tested on samples from oceanic (Atlantic), coastal (Irish Sea) and estuarine (Mersey) origins at Pb concentrations between 30pM and 2nM. The pseudopolarograms were found to resolve the speciation of lead in terms of labile and irreversibly bound Pb species. The lead in the samples was largely in the labile component of the pseudopolarograms, indicating that it was reversibly complexed with values for log α′Pb2+Lof 2 for the oceanic sample, and of 4 for the coastal sample. A smaller fraction was resolved as stable, irreversibly bound species with values for the thermodynamic stability constant of log KPb2+L=15–16. The speciation method was able to resolve metal species occurring at levels of only a fraction of that of the metal. Unlike copper, where organic complexation is strong and electrochemically irreversible, and able to significantly decrease its bioavailability, the Pb mostly occurs in the labile complexed fraction and is therefore readily available for geochemical scavenging or biological uptake reactions.
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使用振动金微丝电极对海水中的铜络合物进行伪极谱分析。
DOI：
10.1021/jp3019155
发表时间：
2012
期刊：
The journal of physical chemistry. A
影响因子：
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作者：
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DOI：
--
发表时间：
1999
期刊：
影响因子：
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影响因子：
1.8
作者：
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K. Powell;P. Brown;R. Byrne;T. Gajda;G. Hefter;S. Sjöberg;H. Wanner
影响因子：
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