Used as a reagent in analytical chemistry for the determination of various cations, particularly quaternary ammonium compounds and certain metal ions. It forms insoluble precipitates with large cations, enabling gravimetric or titrimetric analysis. Commonly applied in pharmaceutical testing to assay nitrogen-containing compounds. Also utilized in ion-selective electrode preparations due to its ability to form ion pairs. The solution is effective in qualitative inorganic analysis for the separation and identification of cations in mixtures.