[SAD MAN]

Determination of NH3
Hi everybody, 

In order to determine the ammonia in seawater, 4500-NH3 F. Phenate Method, is used.

I have two questions :

What are the equations of the reactions that occur in this methods, see the Principle.

In the end the absorbance of the solution Measure at 640 nm, this absorbance for which compound???




Waiting your answers and comments

[allanf]

This reaction is sometimes called the Berthelot reaction or the Indophenol Method.  The former as Berthelot first published it in 1859, the latter as it produces Indophenol in the end.

I made up a quick sketch (its not balanced) from Talanta, 1989, volume 36 pages 261-269.

The final absorbance measured is for Indophenol or the analogue for whichever phenol you choose to use (salicylate is common).

[SAD MAN]

Hi

Thanx alot Allan, you solve this big problem,,,

IF YOU CAN, if you have the paper that u used (Talanta, 1989, volume 36 pages 261-269), can u send it to me?


thanx againe