AOAC RI ERP EBOOK FOR FERTILIZERS

In the reaction of urea, formaldehyde, and ammonia, a highly water soluble ring structure known as urea-triazone predominantly forms.

O

O

+

NH 3

+

H 2 N

NH 2

H H

O

H

H

N

N

Urea-Forms +

N

R R = H, CH 3 , CH 2 OH, CH 2 NHCONH 2

In most of these products produced from the reaction of urea and formaldehyde, or urea-formaldehyde- ammonia, the reaction products contain SRN in the form of aqueous solutions of water-soluble organic nitrogen species and some unreacted, free urea. The unreacted or free urea provides readily available nitrogen and therefore should be deducted from the slowly released nitrogen portion. Quantitative analysis of these SRN fertilizer solutions for all of the reacted nitrogen forms in these fertilizers is time consuming and impractical or even impossible. The complex composition of an example of a fertilizer produced from the reaction of urea, formaldehyde, and ammonia is shown in Figure - 1 below: Figure 1 Liquid Chromatography of Triazone Fertilizer