Used as a reagent in analytical chemistry for the detection and determination of formaldehyde and other aldehydes. It forms a colored complex with formaldehyde, which is measured spectrophotometrically for quantitative analysis. Also employed in the determination of nitrite and nitrate ions in water and environmental samples. In histology, it serves as a staining agent to identify specific tissue components. Additionally, it is utilized in the synthesis of dyes and as a pH indicator in certain chemical reactions. Its ability to form stable complexes makes it valuable in various industrial and research applications.