# Quantitative Analysis of Urea in aq. solution

What would be a good way to assay Urea in aq. solution? The test doesn't need to be super accurate. 1% accuracy is fine.

But it needs to be relatively fast & robust to carry out.

NaHCO3 is a co-dissolved impurity so the test needs to tolerate NaHCO3 interference.

• react the ammonia with 2-oxo-glutarate in the presence of glutamate dehydrogenase and $\ce{NADH}$: $\ce{NADH}$ is converted to $\ce{NAD+}$
• monitor the decay of the UV absorption of $\ce{NADH}$ at $\lambda$= 340 and 410 nm
• @curious_cat I'm not aware of any, but that's doesn't necessarily mean that there isn't any. There's another method that involves the reaction of urea with diacetyl monoxime. But again, this requires a photometer to monitor the absorption at $\lambda$= 525 nm. – Klaus-Dieter Warzecha May 2 '16 at 4:52