Potassium phosphate monobasic (Monopotassium phosphate) is a commonly used in biological assay buffers. Potassium phosphate monobasic is moderate to highly concentrated aqueous solutions of potassium phosphate monobasic for the production of phosphate buffers and other laboratory applications. Potassium phosphate monobasic (KH2PO4) also used as a fertilizer, food additive, and buffering agent.