Multifunctional Portable System Based on Digital Images for In-Situ Detecting of Environmental and Food Samples

Abstract

The development of a portable device created by 3D printing for colorimetric and fluorometric measurements is an efficient tool for analytical applications in situ or in the laboratory presenting a wide field of applications in the environmental and food field. This device uses a light-emitting diode (LED) as radiation source and a webcam as a detector. Digital images obtained by the interaction between the radiation source and the sample were analyzed using a programming language developed in Matlab (Mathworks Inc., Natick, MA, USA), which builds the calibration curves in real-time using the RGB colour model. In addition, the entire system is connected to a notebook which serves as an LED and detector power supply without the need for any additional power source. The proposed device was used for the determination in situ of norfloxacin, allura red, and quinine in water and beverages samples, respectively. For the validation of the developed system, the results obtained were compared with a conventional spectrophotometer and spectrofluorometer respectively with a t-test at a 95% confidence level, which provides satisfactory precision and accuracy values.

Selective ionization of marker molecules in fuels by laser-based ion mobility spectrometry (LIMS)

“…Tagging options include, for example, magnetic inks, uorescent labels, photochromic and thermochromic coatings, isotopic tracers and Raman-active components. 5,6 Most of these physical methods are designed for labelling solid surfaces or are incorporated directly into the product during manufacture.…”

A novel in situ method for linear alkylbenzene sulfonate quantification in environmental samples using a digital image-based method

“…24 The novelty of the present study lies in using the DIB method to measure a specic molecular marker of sewage contamination, i.e., LAS; previous studies have used the DIB method to measure other parameters of water quality such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), coliforms, chlorophyll, total solids, phosphate, and emerging pollutants. [43][44][45] To date, there have been no reports in the literature regarding the use of the DIB method with a smartphone for the in situ analysis of LAS. In this sense, the present study sought to use the DIB/smartphone method for the analysis and determination of LAS in the Capibaribe River Estuarine System (CES), which has suffered from this type of pollution recently.…”