text: Berthelot's reagent has been used in a range of situations. It is often used in colorimetric methods, through an AutoAnalyzer, spectrophotometer, or multiwell plate spectrophotometer. The reagent lacks sensitivity in situations where there may be amines as well as ammonia, however this can be overcome in part by the use of 2-phenylphenol to replace phenol. 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.