Webcam camera as a detector for a simple lab-on-chip time based approach

Wongwilai, Wasin; Lapanantnoppakhun, Somchai; Grudpan, Supara; Grudpan, Kate

doi:10.1016/j.talanta.2010.01.058

Cited by 43 publications

(24 citation statements)

References 11 publications

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“…Digital image analyses are found for analytical methods in different matrices [17][18][19][20][21][22][23][24][25][26][27][28][29][30] and also for environmental monitoring and remote sensing [31,32]. For instance, Paciornik et al [31] quantified Hg in fish samples using analysis of color descriptors (Hue-Lightness-Saturation, HLS and Cyan-MagentaYellow, CMY) from digital images of a spot test system.…”

Section: Introductionmentioning

confidence: 99%

Proposition of a simple method for chromium (VI) determination in soils from remote places applying digital images: A case study from Brazilian Antarctic Station

Oliveira

Canevari

Guerra

et al. 2013

Microchemical Journal

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In this study, we proposed a straightforward approach that could be used for Cr redox speciation in soil samples from remote places. For this aim, soil samples under strong anthropogenic impact, from the vicinity of the Brazilian Antarctic Station were studied. Control samples with no direct impact, were also collected further (4 km) from the station. A preliminary laboratory evaluation for Cr (VI) presence was performed using X-ray absorption spectroscopy. The proposed method was based on a hot alkaline extraction to promote the quantitative extraction of Cr (VI) from soil samples. The colorimetric reagent 1,5-diphenylcarbazide (DPC) was added to the extracts to form a violet complex with Cr (VI). A simple and inexpensive commercial scanner was used to acquire the digital images of the formed complex. Partial Least Squares models were constructed with the following average color descriptors: red (R), green (G), blue (B), hue (H), saturation (S), value (V), relative color descriptors (r, g and b) and luminosity (L). The results obtained with this scanner approach were consistent with the official method that uses a spectrophotometer at 540 nm. Besides that, this is the first study that reports Cr redox speciation in soils from Antarctica, which is regarded as the less polluted place on the Earth.

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Section: Introductionmentioning

confidence: 99%

Proposition of a simple method for chromium (VI) determination in soils from remote places applying digital images: A case study from Brazilian Antarctic Station

Oliveira

Canevari

Guerra

et al. 2013

Microchemical Journal

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“…Six white high intensity LEDs (NPE, Thailand) were placed at the ceiling of the box to give a constant light intensity throughout the experiment. The interior walls of the box were covered with white paper in order to provide uniform illumination and reduce glare [8,16,19]. …”

Section: Assembly Of the Dib-μfba Systemmentioning

confidence: 99%

“…Mathematical models for digital images and RGB data have also been employed to construct analytical curves in quantitative determinations [14][15][16]. Lyra et al [17] proposed a method using the norm for position vectors in an RGB three-dimensional space concept.…”

Section: Introductionmentioning

confidence: 99%

A digital image-based micro-flow-batch analyzer

Lima

Andrade

Barreto

et al. 2013

Microchemical Journal

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This paper introduces for the first time the combination of digital images taken with a webcam and a microflow-batch analyzer as a novel strategy for implementing quantitative chemical analysis. The digital imagebased micro-flow-batch analyzer (DIB-μFBA) was formed using urethane-acrylate resin, glass slides and ultraviolet lithography. The glass slides were used as sealant layers on both sides of the substrate urethane-acrylate and provide the necessary transparency to the microsystem to conduct studies using digital images. DIB-μFBA uses digital images obtained from a webcam with CCD sensor, based on the RGB (red-green-blue) color model. The analyzer was used for determining the tannins in green tea employing the well-known ferrous tartrate method. All standard solutions were prepared in-line, and all analytical processes were completed by simply changing the operational parameters in DIB-μFBA control software. The paired t test, at a 95% confidence level, showed no statistically significant differences between results obtained by DIB-μFBA and the spectrophotometric reference method. The proposed microsystem presented satisfactory physical and chemical properties while keeping the flexibility, versatility, robustness and multi-task characteristics of conventional flow-batch analysis. Therefore, it was possible to build a low-cost device with high sample throughput (about 190 h −1 ) and reduced reagent consumption (about 300 times less than the reference method), contributing to the basic principles of green chemistry and the advancement of micro-analytical procedures.

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“…Reagent mediated analyses have been extensively studied in which digital images describing color development of one-shot sensing spots were evaluated [4,6,8,10]. There has also been work done using digital images of solutions based on their spectral properties [11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Classification and quantitative optical analysis of liquid and solid samples using a mobile phone as illumination source and detector

Iqbal

Eriksson

2013

Sensors and Actuators B: Chemical

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A mobile phone has been used both as illumination source and image detector for quantitative optical analysis of colored liquid samples (4 different colorants) and solid samples (printed color patterns, plastic beads and colored sand grains). Even though the measurement conditions were far from ideal, because the light source was strongly polychromatic and the illumination was not a collimated light beam with homogeneous light intensity, a logarithmic concentration dependence, in accordance with the Beer-Lambert law, described the data of the colored liquids quite well. By utilizing blue-blue (420-510 nm), green-green (480-590 nm) and red-red (575-695 nm) illumination/detection combinations, each sample could be assigned a unique color signature for classification that agreed with reference absorbance spectra measured with a spectrometer. Quantification of validation samples within a few percent of the actual values was achieved. Also the long-term repeatability of the measurements was investigated and was surprisingly good for such a simple system. Analysis of the colored solid samples was more complex with results being dependent on the morphology and colorimetric properties of the samples

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Webcam camera as a detector for a simple lab-on-chip time based approach

Cited by 43 publications

References 11 publications

Proposition of a simple method for chromium (VI) determination in soils from remote places applying digital images: A case study from Brazilian Antarctic Station

Proposition of a simple method for chromium (VI) determination in soils from remote places applying digital images: A case study from Brazilian Antarctic Station

A digital image-based micro-flow-batch analyzer

Classification and quantitative optical analysis of liquid and solid samples using a mobile phone as illumination source and detector

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