Berthelot's reagent
| Classification | Colorimetric method |
|---|---|
| Analytes | Ammonia |
Berthelot's reagent is an
colorimetric method for determining ammonia. The reagent can also be used for determining urea. In this case the enzyme urease is used to catalyze the hydrolysis of urea into carbon dioxide
and ammonia. The ammonia is then determined with Berthelot's reagent.
Variations
Phenol in the Berthelot reagent can be replaced by a variety of phenolic reagents, the most common being
2-phenylphenol reduces interferences by a variety of soil and water constituents and improves color stability at slightly lower pH.[2]
Uses
Berthelot's reagent has been used in a range of situations. It is often used in colorimetric methods, through an
ion selective electrode
, or distillation/titration method can often be used in cases where Berthelot chemistry is ineffective.
Berthelot chemistry has also been adapted for the analysis of nitrite and nitrate in soil and water after conversion, typically by reduction with Devarda's alloy, of these species to ammonium.[3]
References
Further reading
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