Recently, analytical procedures based on computer vision related to the colorimetric analysis of digital images have been described in the scientific literature. In this sense, a novel analytical approach is presented based on digital image colorimetry for nickel determination. The method consists in the development of a system with solid-phase extraction, consisting basically of an extraction chamber filled with polystyrene divinylbenzene sorbent impregnated with the complexing reagent 1-(2-thiazolylazo)-p-cresol (TAC) and a portable microscope multifunction, used for image acquisition. The image of the sorbent after extraction of Ni is obtained. This image is related to the concentration of the elements. The variables (pH, flow, and sample volume) were evaluated using a full factorial design 2³ for the screening and a Doehlert matrix to establish the significant variables’ optimal levels. The enrichment factor and limit of detection were 148 and 0.8 μg L⁻¹, respectively. The method was applied to the determination of nickel in river water, coffee, and cigarette samples.

中文翻译：

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直接在吸附剂中进行固相萃取和数字图像检测：环境样品中镍的测定

最近，在科学文献中已经描述了基于计算机视觉的与数字图像的比色分析有关的分析程序。从这个意义上讲，提出了一种基于数字图像比色法测定镍的新颖分析方法。该方法包括开发一种具有固相萃取的系统，该系统主要由一个装有聚苯乙烯二乙烯基苯吸附剂的萃取室组成，该吸附剂中充满了络合剂1-（2-噻唑基偶氮）-对甲酚（TAC）和便携式多功能显微镜，用于图像获取。获得镍萃取后的吸附剂图像。该图像与元素的浓度有关。使用全因子设计评估变量（pH，流量和样品量）2 ³进行筛选，并用Doehlert矩阵确定重要变量的最佳水平。富集因子和检测极限分别为148和0.8μgL ^-1。该方法用于测定河水，咖啡和香烟样品中的镍。