Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Portugal.
Anal Chim Acta. 2011 Aug 12;699(2):193-7. doi: 10.1016/j.aca.2011.05.018. Epub 2011 May 20.
A novel flow method for the determination of chemical oxygen demand (COD) is proposed in this work. It relies on the combination of a fully automated single interface flow system, an on-line UV photocatalytic unit and quantum dot (QD) nanotechnology. The developed approach takes advantage of CdTe nanocrystals capacity to generate strong oxidizing species upon irradiation with UV light, which fostered a fast catalytic degradation of the organic compounds. Luminol was used as a chemiluminescence (CL) probe for indirect COD assessment, since it is easily oxidized by the QD generated species yielding a strong CL emission that is quenched in the presence of the organic matter. The proposed methodology allowed the determination of COD concentrations between 1 and 35 mg L(-1), with good precision (R.S.D.<1.1%, n=3) and a sampling frequency of about 33 h(-1). The procedure was applied to the determination of COD in wastewater certified reference materials and the obtained results showed an excellent agreement with the certified values.
本工作提出了一种测定化学需氧量（COD）的新流动方法。它依赖于全自动单界面流系统、在线 UV 光催化单元和量子点（QD）纳米技术的结合。所开发的方法利用 CdTe 纳米晶体在受到 UV 光照射时产生强氧化剂的能力，促进了有机化合物的快速催化降解。鲁米诺被用作间接 COD 评估的化学发光（CL）探针，因为它很容易被 QD 产生的物质氧化，产生强 CL 发射，而在有机物存在下会被猝灭。所提出的方法允许在 1 至 35mgL(-1)之间测定 COD 浓度，具有良好的精密度（R.S.D.<1.1%，n=3）和约 33h(-1)的采样频率。该程序被应用于废水标准参考物质中 COD 的测定，所得结果与认证值吻合良好。
