Facultad de Química, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile.
Talanta. 2009 Nov 15;80(1):184-8. doi: 10.1016/j.talanta.2009.06.046. Epub 2009 Jul 1.
A simple and sensitive electroanalytical method is developed for the determination of lead by adsorptive stripping voltammetry (AdSV) in the presence of morin-5'-sulfonic acid (MSA) and sodium dodecyl sulfate (SDS). The Pb-MSA complex accumulates on the surface of a hanging mercury drop electrode (HMDE) and peak current is measured by square wave voltammetry (SWV). The complex is reduced at -0.48 V and peak current increases when low concentrations of SDS are added to the sample solution. The experimental variables pH, MSA concentration (C(MSA)); accumulation time (t(acc)); accumulation potential (E(acc)), and SDS concentration (C(SDS)), as well as potential interferences, are investigated. Under the optimized conditions (pH 3.2; C(MSA): 0.5 micromol L(-1); t(acc): 60s; E(acc): -0.35 V, and C(SDS): 20 micromol L(-1)), peak current is proportional to the concentration of Pb(II) over the 0.1-32.0 microg L(-1) range, with a detection limit of 0.04 microg L(-1). The relative standard deviation for a solution containing 5.0 microg L(-1) of Pb(II) solution was 1.5% for seven successive assays. The method was validated by determining Pb(II) in synthetic sea water (ASTM D665) spiked with ICP multi-element standard solution and in certified reference water (GBW08607). Finally, the method was successfully applied to the determination of Pb(II) in tap water and sea water after UV digestion.
一种简单灵敏的电化学分析方法，用于在存在桑色素-5'-磺酸（MSA）和十二烷基硫酸钠（SDS）的情况下，通过吸附溶出伏安法（AdSV）测定铅。Pb-MSA 络合物在悬汞滴电极（HMDE）表面上累积，并通过方波伏安法（SWV）测量峰电流。该络合物在-0.48V 下还原，当向样品溶液中加入低浓度 SDS 时，峰电流增加。实验变量 pH、MSA 浓度（C(MSA)）；累积时间（t(acc)）；累积电位（E(acc)）和 SDS 浓度（C(SDS)）以及潜在干扰因素都进行了研究。在优化条件下（pH 3.2；C(MSA)：0.5 μmol L(-1)；t(acc)：60s；E(acc)：-0.35V，和 C(SDS)：20 μmol L(-1)），峰电流与 0.1-32.0μg L(-1)范围内的 Pb(II)浓度成正比，检测限为 0.04μg L(-1)。对于含 5.0μg L(-1)Pb(II)溶液的溶液，连续测定 7 次，相对标准偏差为 1.5%。该方法通过向 ICP 多元素标准溶液中添加合成海水（ASTM D665）和认证参考水（GBW08607）中的 Pb(II)并进行测定来验证。最后，该方法成功应用于 UV 消解后的自来水和海水中 Pb(II)的测定。
