Used primarily as a reagent in biochemical assays, particularly for the detection and quantification of phenolic compounds. It reacts with phenols in the presence of an oxidizing agent to form a colored complex, which can be measured spectrophotometrically. This property makes it valuable in water quality testing, where it helps identify phenolic contaminants. Additionally, it is employed in clinical diagnostics to measure enzyme activities, such as peroxidase, by serving as a substrate in enzymatic reactions. Its role in these applications underscores its importance in environmental monitoring and medical research.