Digital movie-based on automatic titrations

Digital image colorimetry coupled with a multichannel membrane filtration-enrichment technique to detect low concentration dyes

“…S3. † In addition, the relative standard deviations (RSDs) of the 3, 8, 15, 20, 30 and 40 mg L À1 solutions for each dye (2,5,8,12,16 and 20 mg L À1 for Auramine O) obtained from the RGB and spectral data are also presented in Table 2. As revealed in Table 2, the LOD calculated with ÀB/I for each dye is higher than that calculated with absorbance, while the RSDs obtained from ÀB/I are in a lower range than those obtained from absorbance.…”

“…Thus, the digital camera can act as an analytical detector and has been frequently employed for chemical analyses which involve the production of chemical color changes. [1][2][3][4][5][6] The principle of the digital image-based quantitative determination method can be interpreted as colorimetry by reecting light, 7,8 i.e., the light reaching each pixel in the CCD or CMOS is the light reected by objects. The analytical data extracted from the digital image are a standard trichromatic response consisting of red (R), green (G) and blue (B) components.…”

“…Thus, RGB responses from different pictures usually can't be employed for analytical purposes without being processed. 11 To solve this problem, the common method used by many researchers 4,5,7,[12][13][14][15] is taking pictures in a xed condition or even in a specially designed device to ensure a repeatable and uniform illumination, and setting a same color reference-object in all pictures, then selecting xed regions to extract the RGB responses for samples and the reference-object, respectively, and nally, calibrating the RGB values of the samples with those of the reference-object. For eld or routine analysis, preparing a xed condition or device for taking a picture seems a bit troublesome.…”

Inner Product of RGB Unit Vectors for Simple and Versatile Detection of Color Transition

“…Applying image-based colorimetry to flow analysis, Gaiao et al 6,7 sampled the titrand from a reaction vessel on-line to determine the indicator's color transition based on RGB values. Digital movie-based titrations by flow-batch methods 8,9 employed the RGB and Hue values for the equivalence point detection. However, selecting an appropriate tristimulus value (i.e., R, G, or B-value) is needed in advance, depending on the indicators' color.…”

Estratégias em fluxo para a determinação de acidez, sulfato e cloreto em etanol hidratado combustível

“…Recentemente, foi relatado, por pesquisadores brasileiros, o emprego de imagens digitais, aliadas à estratégia de fluxo-batelada para a determinação automática do ponto final em titulação colorimétrica com e sem indicador químico [70][71][72]. Outros autores relataram a exploração de traçadores químicos para realização de titulações em fluxo, sem a necessidade da construção de curvas de calibração.…”