By Anton Paar USA
UAN is a solution of urea, ammonium nitrate and water that is used as a fertilizer. Both fast acting and long lasting nourishment is provided by three forms of nitrogen. These are ammonic nitrogen, nitrate and the water soluble organic nitrogen in urea.
Typically, UAN is analyzed to determine the concentrations of ammonium nitrate, urea and total nitrogen. A common grade of these fertilizer solutions is UAN 32, which is 45% ammonium nitrate, 35% urea and 20% water resulting in a total nitrogen concentration of 32%.