Electroanalytical and chromatographic determination of pentachlorophenol and related molecules in a contaminated soil: a real case example
Electroanalytical and chromatographic determination of pentachlorophenol and related molecules in a contaminated soil: a real case example
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DOI：
10.1016/j.microc.2004.02.011
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发表时间：
2004-08
影响因子：
4.8
通讯作者：
L. Codognoto;V. Zuin;D. Souza;J. H. Yariwake;S. Machado;L. Avaca
中科院分区：
文献类型：
--
作者：
L. Codognoto;V. Zuin;D. Souza;J. H. Yariwake;S. Machado;L. Avaca
采用电分析和色谱分析方法对工业排放污染土壤样品中的五氯苯酚(PCP)及其部分衍生物进行了测定。分析物用己烷从现场不同地点采集的土壤样本中提取，并混合在一起产生具有代表性的样本。在pH为5.5的Britton-Robinson(B-R)缓冲液中，直接加入适量的萃取物，在掺硼金刚石(BDD)电极和金超微电极(Au-UME)上进行了方波伏安(SWV)实验。伏安响应在约0.80V处出现一个不可逆阳极峰，峰电流与PCP浓度呈线性关系。线性关系良好，电极的检出限为2×10−8mol L−1(或5.5μg L−1)，金的检出限为6.9×10−8molL−1(18.4μg L−1)，而高效液相色谱法的检出限为1.1×10−8molL−1(3.0μg L−1)。电分析和层析方法在土壤萃取物分析中的应用，除了PCP的响应外，还显示了一些相关分子的信号，如邻氯苯酚、六氯苯和四氯苯酚。对五氯苯酚的回收实验表明，电分析测定的浓度为27.5mgkg−1，高效液相分析的浓度为26.8mgkg−1，如果考虑到巴西环保局规定的天然水最大残留限量为10μg L−1，这两个值都非常高。
Electroanalytical and chromatographic methodologies have been applied for the determination of pentachlorophenol (PCP) and some of its derivatives in real soil samples contaminated by industrial discharge. The analytes were extracted with hexane from soil samples collected at different points of the site and mixed to produce a representative sample. Square wave voltammetry (SWV) experiments were carried out on either a boron-doped diamond (BDD) electrode or a gold ultramicroelectrode (Au-UME) in an analyte composed by the Britton-Robinson (B-R) buffer at pH 5.5 with the direct addition of proper amounts of the extract. The voltammetric responses revealed an irreversible anodic peak at approximately 0.80 V vs. Ag/AgCl with a peak current showing a linear dependence on PCP concentration. This linear relationship yielded a detection limit (DL) of 2×10−8mol l−1(or 5.5 μg l−1) for the BDD electrode and 6.9×10−8mol l−1(18.4 μg l−1) for the Au-UME, while the independently measured HPLC detection limit was 1.1×10−8mol l−1(3.0 μg l−1). The application of electroanalytical and chromatographic methodologies in the analysis of soil extracts revealed, besides the PCP responses, signals for some related molecules such as o-tetrachlorobenzoquinone (o-chloranil), hexachlorobenzene and tetrachlorophenol. Recovering experiments for PCP showed a concentration of 27.5 mg kg−1for the electroanalytical determinations and 26.8 mg kg−1for the HPLC analysis, values exceedingly high if considering that the maximum residue limit established for natural waters by the Brazilian Environmental Agency is 10 μg l−1.