Used in analytical chemistry as a source of the tetraphenylborate anion, serving as a precipitating agent for the determination and separation of alkali metal cations such as potassium, cesium, and ammonium. It enables selective isolation of these ions from complex mixtures, particularly in environmental and geological samples. Also employed in the synthesis of specialized organoboron compounds and in research for studying ion-pair interactions in solution. Its low solubility in water makes the resulting precipitates suitable for gravimetric analysis.