Chemistry Meets Environmental Science: A Simple Colorimetric Assay for Glyphosate Detection in School Laboratories

Abstract

Glyphosate is the most widely used herbicide globally, with ongoing concerns about its toxicological relevance, especially in relation to potential environmental concerns. This emphasizes the need for simple and rapid environmental analysis methods. Promising low-cost techniques for detecting glyphosate are colorimetric indicator displacement assays, which use an indicator that forms a colored complex with a metal ion. When the analyte is added, it displaces the metal ion, causing a color change that can be captured by a smartphone camera and quantified by a calibration curve. For this experiment, a state-of-the-art assay based on copper(II)-pyrocatechol violet developed in recent research was adapted for classroom use. The experiment demonstrates the qualitative detection of glyphosate in herbicide formulations, the quantitative determination of glyphosate concentrations in water samples, and its removal from wastewater using activated carbon. Additionally, it integrates current research, highlighting the role of the transformation of detergent additives in glyphosate contamination in European waters. By engaging with this experiment, students gain hands-on experience with modern analytical techniques and explore the link between chemistry and environmental sustainability. This experiment connects classroom learning to contemporary scientific issues, fostering critical thinking about chemical pollution, environmental impact, and the importance of analytical chemistry in addressing real-world challenges.