Department of Analytical Chemistry, Faculty of Sciences, University of Cadiz, P.O. Box 11510, Campus Río S. Pedro, Puerto Real, Cadiz 11510 Spain.
Appl Spectrosc. 2014;68(4):413-20. doi: 10.1366/13-07126.
A new sensor based on the use of 2-hydroxybenzaldehyde benzoylhydrazone as a colorimetric reagent immobilized onto styrenedivinylbenzene disks has been carried out for the determination of Cu(II) ions within several minutes. The sensor is designed on a rapid and easy two-step procedure: (1) the extraction of Cu(II) ions onto a disk loaded with the copper-selective colorimetric reagent and (2) the determination of the complexed analyte directly on the surface of the disk using diffuse reflectance measurements at 400 nm. The color of the disk changed from white to green in the presence of Cu(II) ions. The work herein details the optimization of the sensing system employing a fractional factorial design 3(3-1) considering three variables (pH, immobilization time, and amount of ligand immobilized onto the disk). The Pareto chart and response surfaces in a spherical domain indicated that the optimum conditions for the sensing of copper ions were pH = 7, with a ligand immobilization time of 10 min and 6.25 mg of reagent loaded onto the disk. Under the optimum conditions, the analytical parameters of the proposed method were determined. The calibration graph was linear over the range of 0 to 2.5 mg L(-1) of Cu(II) with a detection limit of 0.21 mg L(-1). The relative standard deviation for six measurements of 1 mg L(-1) of Cu(II) was found to be 4.87%. The interference from inorganic salts and other metals was found not to be of major concern when monitoring copper ions in water samples. The simplicity and rapidity of this technique make it convenient and amenable for on-site and routine analysis.
一种基于 2-羟基苯甲醛苯甲酰腙作为显色试剂固定在苯乙烯-二乙烯基苯圆盘上的新型传感器，已在几分钟内实现了对 Cu(II)离子的测定。该传感器是基于快速简便的两步法设计的：（1）将 Cu(II)离子萃取到负载铜选择性显色试剂的圆盘上；（2）直接在圆盘表面上使用漫反射测量法在 400nm 处测定络合分析物。在存在 Cu(II)离子的情况下，圆盘的颜色从白色变为绿色。本文详细介绍了采用 3(3-1)分数因子设计优化传感系统，考虑了三个变量（pH、固定化时间和固定在圆盘上的配体量）。Pareto 图和球域中的响应曲面表明，用于感测铜离子的最佳条件为 pH=7，配体固定化时间为 10min，并且将 6.25mg 的试剂负载到圆盘上。在最佳条件下，确定了所提出方法的分析参数。校准曲线在 0 至 2.5mg L(-1)的 Cu(II)范围内呈线性，检测限为 0.21mg L(-1)。在 1mg L(-1)的 Cu(II)的六个测量值的相对标准偏差为 4.87%。当监测水样中的铜离子时，发现无机盐和其他金属的干扰不是主要问题。该技术的简单快速使其便于现场和常规分析。
