A Simple Methods for Determination of Methylene Blue using Smartphone-Based as Digital Image Colorimetry

Abstract

The advancement of smartphones that produce high-resolution photos has made their use even more developed. One application that is currently developing is a digital image produced as colorimetry. Digital image-based colorimetry is an easy and simple determination method and can be an alternative for analyzing dyes quantitatively. In this method, the color response of the digital image is analyzed, namely red-green-blue (RGB) with values from 0 to 255. This data is extracted from digital images using ImageJ 1.52a software for quantitative determination. In this study, 2 standard methods were used, namely external standards and standard addition to evaluating the most suitable method to obtain accurate measurements. In addition, 2 methods were used to determine the relationship of response to methylene blue levels. The 1st method used simple linear regression of each color red, green, or blue (univariate). The 2nd method is used in multivariate linear regression of the 3 colors red, green, and blue. The accuracy of the method was validated using UV-Vis spectrophotometry as the reference method. The results showed that the multivariate models produced very good accuracy, namely precision of up to 99 % compared to the simple regression method with the univariate. HIGHLIGHTS Smartphone cameras can be applied easily as a simple, fast, and inexpensive colorimetric method for quantitative analysis of methylene blue content The univariate models for external standard and standard addition methods showed up to 90 % precision for fish drug samples against UV-Vis spectrophotometric methods The multivariate models for the external standard method provide up to 99 % precision results for fish drug samples against UV-Vis spectrophotometric methods· GRAPHICAL ABSTRACT

Smartphone Digital Image Colorimetry: An Affordable Easy-To-Use Approach for Hands-On Training in Resource-Limited Settings

“…Other biomolecules analyzed with SDIC include urinary albumin [58], DNA [59], tyrosinase [60], and urea [61]. Similarly, SDIC for chemical analysis is well documented in recent years, such as in the study of Cu 2+ [62], Hg 2+ [63], paraoxon herbicides [64], pesticides (paraoxon, malathion, and methyl parathion ) [65,66], tetracycline [67], methylene blue [68], Pb 2+ [63], among others. In the aspect of food processing and safety, SDIC has been developed for the quantitative detection of nitrite in food samples (cabbage, pickle, and ham) leveraging the colorimetric oxidation chemistry between nitrite and 3,3′,5,5′-tetramethylbenzidine (TMB) [69].…”

Colorimetric Sensing of Ascorbic Acid Using Cu-Phen MOFs and Subsequent Digital Image Analysis with Smartphone

“…DIC or Digital image colorimetry using a smartphone is a rapidly growing analytical method that received large attention among the analytical chemists due to their simplicity, easy on use, low cost and portable (de Carvalho Oliveira et al, 2022;Firdaus et al, 2023). DIC has been used to determine heavy metals (Firdaus et al, 2014;Firdaus et al, 2019;Masawat et al, 2022;Meelapsom et al, 2022), biomolecules (Firdaus et al, 2022), chemicals in food and textiles industries (Eddy et al, 2023;Masawat et al, 2015;Permana et al, 2023;Yadav et al, 2022), etc. Furthermore, the DIC method can be combined with chemometrics analysis for further application in various fields and samples (Gaião Calixto et al, 2023;Gusti et al, 2021).…”