RAPID COLORIMETRIC DETEСTION OF Fe(III) IONS IN WATER USING A SMARTPHONE: RGB ANALYSIS OF DIGITAL IMAGES

Abstract

The paper describes a new approach to quantifying the concentration of Fe³⁺ ions in water using a smartphone, which allows the analysis with sufficient accuracy and sensitivity. The RGB parameters were converted into specific parameters R', G', B' in order to improve the linearity of the calibration curves and increase the detection limit. This work shows the high accuracy of the detection method of the Fe³⁺ concentration in the range from 0.1 to 5.0 mg/L with a correlation coefficient of 0.9916. The accuracy of colorimetric analysis using a smartphone was confirmed using a ULAB 102-UV spectrophotometer. The simplicity and sensitivity of this approach make the smartphone an alternative to professional spectrophotometers.