A digital image-based micro-flow-batch analyzer

• Published in: Microchemical journal Vol. 106; pp. 238 - 243
• Main Authors: Lima, Marcelo B., Andrade, Stéfani Iury E., Barreto, Inakã S., Almeida, Luciano F., Araújo, Mário César U.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2013
• Subjects: Digital images; Green tea; Micro-flow-batch analyzer; RGB color model; Tannins; Urethane-acrylate resin; Tannins; Micro-flow-batch analyzer; Urethane-acrylate resin; Digital images; Green tea; RGB color model
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2012.07.010

This paper introduces for the first time the combination of digital images taken with a webcam and a micro-flow-batch analyzer as a novel strategy for implementing quantitative chemical analysis. The digital image-based 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 190h−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. ► A digital image-based micro-flow-batch analyzer (DIB-μFBA) is presented. ► A simple and low-cost ultraviolet-lithographic microfabrication technique was used. ► The proposed microsystem was applied to tannin determination in green tea. ► The DIB-μFBA displays high sample throughput and reduced reagent consumption.