Urea in soil method

[H.Thomas]

Dear community,

I have been lurking around this forum for quite a while, and have learned a lot. Thank you all.

Now I have a problem and hope somebody can show me the right direction. I am trying to determine urea in soil. Concentrations are expected to be very low. Experiments with LCMS showed nothing, even in the standards.

I have done some literature search, but all I found are spectrophotometric methods with LODs that are too high. Has anybody come across a HPLC (or LC/MS) method for determining urea? Could derivatization with p-dimethylaminobenzaldehyde or diacetymonoxime also be used with HPLC? Or are there any other derivatizing reagents that would be suitable for urea?

Thank you

Hartmut

[Mark Tracy]

Many years ago, when I worked elsewhere, I showed that diacetylmonoxime could be used as a post-column reagent for HPLC. The bad news is that the reagent is corrosive, and you would need a non-metallic post-column reaction system. Try contacting Pickering Laboratories to see if they still can find my old notes. www.pickeringlabs.com