Ammonia detection using the salicylate method

[turtle1769]

Hi, 

I am trying to find a protocol for a modified Berthelot ammonia assay using salicylate and a catalyst.

I am struggling to find a protocol that describes the individual reagent recipes and the precise protocol to follow for the assay such as; 

How much of each reagent to add, when to add each reagent, how to long to leave the sample to process in each step? 

I am hoping to use a method that does now require a water bath and allows the reaction to occur at room temperature with the use of a catalsyt. I will also be using it on seawater samples so I will need to add some component to help avoid interference for metals or precipitate formation.

Could anybody help with providing such a protocol through the work they have done please?