Digital image-based titrations
Digital image-based titrations
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DOI：
10.1016/j.aca.2006.04.048
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发表时间：
2006-06-16
影响因子：
6.2
通讯作者：
Araujo, Mario Cesar Ugulino
中科院分区：
文献类型：
--
作者：
Gaiao, Edvaldo da Nobrega;Martins, Valdomiro Lacerda;Araujo, Mario Cesar Ugulino
首次提出了利用CCD摄像机（WebCam）获得的数字图像作为一种新的滴定仪器检测技术。称为基于数字图像（DIB）的滴定，其还要求与传统滴定（例如，分光光度法、电位法、电导法）一样，滴定曲线中存在终点的不连续性，这与化学等效条件相关联。DIB滴定中的监测信号是基于RGB的值，其通过使用基于红色、绿色和蓝色系统的建议程序针对每个数字图像计算。应用DIB滴定法测定水溶液中的HCl和H_3PO_4以及矿泉水和自来水中的总碱度。将其结果与分光光度法（SPEC）滴定法进行比较，通过应用配对t检验，在95%置信水平下验证了两种方法的结果之间无统计学差异。两种滴定法测定HCl和H_3PO_4的标准偏差相同，DIB滴定法测定总碱度的精密度略好。DIB滴定被证明是一种有效且有前途的定量化学分析工具，并且由于它采用廉价的设备（网络摄像头）作为分析检测器，因此它为需要仪器检测的滴定提供了经济可行的替代方案。(c)2006 Elsevier B.V.保留所有权利。
The exploitation of digital images obtained from a CCD camera (WebCam) as a novel instrumental detection technique for titration is proposed for the first time. Named of digital image-based (DIB) titration, it also requires, as a traditional titration (for example, spectrophotometric, potentiometric, conductimetric), a discontinuity in titration curves where there is an end point, which is associated to the chemical equivalence condition. The monitored signal in the DIB titration is a RGB-based value that is calculated, for each digital image, by using a proposed procedure based on the red, green, and blue colour system. The DIB titration was applied to determine HCI and H3PO4 in aqueous solutions and total alkalinity in mineral and tap waters. Its results were compared to the spectrophotometric (SPEC) titration and, by applying the paired t-test, no statistic difference between the results of both methods was verified at the 95% confidence level. Identical standard deviations were obtained by both titrations in the determinations of HCI and H3PO4, with a slightly better precision for DIB titration in the determinations of total alkalinity. The DIB titration shows to be an efficient and promising tool for quantitative chemical analysis and, as it employs an inexpensive device (WebCam) as analytical detector, it offers an economically viable alternative to titrations that need instrumental detection. (c) 2006 Elsevier B.V. All rights reserved.