Application Note: Long-Lasting Nourishment From Fertilizers

By Anton Paar USA

UAN is a solution of urea, ammonium nitrate and water. It is used as a fertilizer and provides both fast-acting and long-lasting nourishment from three forms of nitrogen. These are ammonia 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%.

Depending on which instrument models are chosen, the uncertainty of the results will range from approximately 1% to better than 0.25%.