A laponite modified carbon paste electrode was prepared, characterized and applied for the 2,4‐dichlorophenol (2,4‐DCP) voltammetric determination. It takes advantage of the ability of laponite to adsorb phenols, as well as of its availability and very low cost. Kinetic and equilibrium data for 2,4‐DCP adsorption by laponite in aqueous dispersions demonstrated that the adsorption process obeyed a pseudo first order kinetic model and was consistent with the formation of adsorbed multilayers on a surface with heterogeneous pore distribution. The composite paste electrode exhibited a heterogeneous surface with 65 % increased surface area and 27 % enhanced catalytic activity compared to the unmodified one. The adsorptive stripping voltammetric determination of 2,4‐DCP at an electrode with an optimized graphite:laponite ratio of 55 : 15 w% using a 3 min accumulation time at pH 5.5 was found to be suitable for its quantification in the linear concentration range extended up to 50 μmol L⁻¹ with a sensitivity of 0.56 μA L μmol⁻¹ and a LOD of 0.2 μmol L⁻¹ (S/N=3).The 2,4‐DCP electrochemical response was not affected by the presence of some structurally similar phenols, like catechol and p‐nitrophenol, while resorcinol, 2‐chlorophenol, and 4‐chlorophenol presented interferences. The results were validated by 2,4‐DCP determination in spiked tap water.

中文翻译：

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皂石修饰碳糊电极吸附溶出伏安法测定2,4-二氯苯酚。

制备了Laponite修饰的碳糊电极，表征并用于2,4-二氯苯酚（2,4-DCP）伏安法测定。它利用了皂石吸附酚的能力，可用性和极低的成本。皂石在水分散液中吸附2,4-DCP的动力学和平衡数据表明，吸附过程遵循伪一级动力学模型，并且与具有非均相孔分布的表面上形成的多层吸附相一致。与未改性电极相比，复合糊状电极的表面异质性增加了65％，催化活性增强了27％。在优化的石墨：锂皂石比为55的电极上，通过吸附溶出伏安法测定2,4-DCP^-1，灵敏度为0.56μALμmol ^-1，LOD为0.2μmolL ^-1（S / N = 3）.2,4-DCP电化学响应不受某些结构相似的苯酚的存在的影响，例如儿茶酚和对硝基苯酚，而间苯二酚，2-氯苯酚和4-氯苯酚会产生干扰。通过加标自来水中的2,4-DCP测定验证了结果。