2 research outputs found
Irudi Digitalen Analisia: espektrofotometroa ordezkatzen
Irudi digitalen analisia (DIA) teknika multzo batek osatzen du eta helburu nagusia da aztergai den sistema bati buruzko informazio adierazgarria determinatzea sistema horren irudiak erabiliz. Metodoaren abantaila nagusiak bere abiadura, sinpletasuna eta beharrezko lagin kopuru txikia dira (400 μL-tik behera mikroplakak erabiltzen badira), baita sortutako hondakin kopuru txikia ere. Lan honetan DIAren hiru aplikazio desberdin deskribatzen dira: nikel bainuetan aurki daitezkeen konposatu nagusien analisia eta kontrola, hala nola, nikela, amonioa eta sulfatoak; fosfatoen eta pH-aren aldibereko determinazioa malko artifizialetan eta tartrazina eta allura gorria koloratzaileen determinazioa jangaietan. Aplikazio hauetan, mahaigaineko eskanerra eta telefono mugikorra erabili dira irudiak eskuratzeko.; Digital Image Analysis (DIA) consists of a set of techniques that aim to obtain representative information about a system using images of that system. The main advantages of this method are its speed, simplicity and small amount of sample needed (below 400 μL if microplates are used), as well as the small amount of waste created. Three different applications are described for DIA in this work: the determination of some of the major compounds in a nickel electroplating baths, such as nickel, ammonium and sulfate ions; the simultaneous determination of phosphates and pH in different eye drops and the simultaneous determination of the color additives tartrazine and allura red in food products. In these applications, a flatbed scanner and a smartphone were used for image acquisition
Microscale titration of acetic acid using digital colorimetry and paper-based analytical devices
A quantitative method for acid-base titrations in paper-based devices (PADs) is described to analyze acetic acid in vinegar samples. In this work, two different types of PADs were developed: a device for individual spot testing and a microfluidic device. Digital colorimetry was used as the detection method, and the images were acquired using a smartphone and a homemade box with LED lights for controlled image acquisition. Titration curves were built with just eight points, using the R channel based on the gradual color transition from red to blue of litmus, a natural indicator. The endpoint was accurately determined by second derivative calculations. Both systems were applied to fifteen vinegar samples of different types, and good concentration results were obtained in comparison to the reference method. The proposed methodology is simple, fast, environmentally friendly, and surpasses the need for calibration curve construction. Moreover, the subjective endpoint identification is eliminated, and the method was automated to provide a high throughput workflow, suitable for quality control processes and real-time measurements.This work was supported by the Basque Government (Research Group IT1662/22), the University of the Basque Country (pre-doctoral scholarship PIF 19/131), São Paulo Research Foundation (FAPESP) [Grant numbers: 2018/08782–1, and 2022/03250-7], and National Council for Scientific and Technological Development – CNPq (Grant number: 310282/2022-5)