Used primarily for the detection and estimation of phenolic compounds in organic samples. When added to a solution containing phenols, a characteristic color change occurs—typically to violet, blue, or green—depending on the specific phenol present. This reaction makes it a valuable reagent in qualitative analysis in laboratories, especially in pharmaceutical and environmental testing.

Commonly applied in spot tests to quickly identify the presence of phenols in raw materials or reaction mixtures. Also used in educational settings to demonstrate functional group reactivity. In some cases, it helps assess water quality by detecting phenolic contaminants in wastewater or industrial effluents.

Additionally, it serves as a simple, rapid method to test the purity of commercial products where phenolic content must be monitored, such as in resins, adhesives, and antioxidants. The intensity of the color formed can be measured spectrophotometrically for semi-quantitative analysis.