Chromazurol S is widely used as a metallochromic indicator in complexometric titrations, particularly for determining metal ions like aluminum, iron, and zirconium. Its ability to form colored complexes with these metals makes it valuable in analytical chemistry for precise endpoint detection. Additionally, it is employed in spectrophotometric methods to measure metal ion concentrations in various samples, including water and biological fluids. In biochemical research, Chromazurol S aids in studying metal-protein interactions due to its selective binding properties. It is also utilized in histology for staining tissues to visualize metal distribution. Its versatility and sensitivity make it a crucial reagent in both industrial and laboratory settings.