Used as a selective reagent in analytical chemistry for the detection and determination of certain metal ions, particularly in qualitative inorganic analysis. It serves as an indicator in complexometric titrations involving metal cations such as calcium and magnesium. The solution helps in identifying endpoint changes due to distinct color shifts when binding with metal ions in solution. Commonly applied in water hardness testing and in pharmaceutical formulations where precise metal ion control is required. Also utilized in laboratory research for separation and identification of specific cations in mixtures.