Determination of trace selenium content in soil based on methylene blue reduction

Currently used methods for selenium quantification include X-ray fluorescence spectrometry and inductively coupled plasma analysis. However, both methods require expensive equipment, specialized knowledge, making them unsuitable for simple on-site quantification. Therefore, in this study, we developed a simple and rapid method for selenium content determination based on methylene blue reduction. We investigated the feasibility of selenium quantification using a superabsorbent polymer supporting methylene blue. When a selenium solution was added to the polymer, a correlation was observed between the fading time of methylene blue and selenium concentration in the range of 0-10 ppm. These results suggest that selenium content in soil eluate can be quantified using the proposed method. Furthermore, this method enables the determination of selenium content in both aqueous solutions and soil samples. Additionally, it does not depend on temperature, making it suitable for quantifying selenium under various temperature conditions.