Diphenylcarbazide is widely used as a reagent in analytical chemistry for the detection and quantification of metal ions, particularly chromium. It forms a distinctive red-violet complex with hexavalent chromium (Cr(VI)), making it a key tool in environmental testing to monitor water quality and industrial effluents for chromium contamination. Additionally, it serves as an indicator in titrimetric analysis for determining the presence of other metals like lead, mercury, and cadmium. In organic synthesis, diphenylcarbazide is employed as a precursor for the preparation of various derivatives and coordination compounds. Its sensitivity and selectivity make it valuable in both laboratory research and industrial applications for ensuring safety and compliance with environmental regulations.