An Indirect Colorimetric Method for Potassium Determination in Soil Using a Paper Device and Smartphone

  • Thinikan Thongkam Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok
  • Khuanjit Hemavibool Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok

Abstract

This study presents a simple method for determination of potassium in microliter scale using a paper device together with a smartphone. The method begins with the ion-pair extraction of dibenzo-18-crown-6-K+ complex into dichloromethane with an excess amount of calmagite. The aqueous phase containing the remaining calmagite is transferred to the paper device, where a smartphone is used to capture the color and convert to RGB value. The linear detection range was found to cover potassium concentrations from 20 mg L-1 to 120 mg L-1. The detection and quantification are 5.41 mg L-1 and 18.03 mg L-1, respectively. Potassium detection was carried out in a variety of actual soil samples, and the results were validated against spectrophotometric results using a paired t-test, which indicated high accuracy. The proposed method is simple, fast, and inexpensive, and it requires no complicated equipment, making it ideally suited for detection of potassium in soil.

Published
2022-11-19
How to Cite
THONGKAM, Thinikan; HEMAVIBOOL, Khuanjit. An Indirect Colorimetric Method for Potassium Determination in Soil Using a Paper Device and Smartphone. Molekul, [S.l.], v. 17, n. 3, p. 393-400, nov. 2022. ISSN 2503-0310. Available at: <http://jos.unsoed.ac.id/index.php/jm/article/view/6279>. Date accessed: 02 dec. 2022. doi: https://doi.org/10.20884/1.jm.2022.17.3.6279.
Section
Articles