Application Note Distillation of Ammoniacal Nitrogen & Total Volatile Nitrogen

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Vapodest 30s

Vapodest 30s

In this method free ammonia is distilled from the sample using Magnesium oxide slurry mix, which is a very mild alkali. The use of Sodium hydroxide would remove side chain amine groups from the protein molecules and give a falsely high result.

Ammonia analysis may be required from a wide variety of sample types including some foods (fish), fertilisers, soils and silage.

For example:

In silage and other forages free ammonia content is a useful indicator of soilage due too aerobic fermentation occurring.

Or

In fish, bacterial and enzyme action spoils the fish, which results in the formation of volatile bases in particular trimethylamine (TMP), dimethylamine and ammonia. The total volatile nitrogen (TVN) is used as an index of fish spoilage.

In all these methods the principle and method are very similar.

The Ammonia or volatile nitrogen is steamed distilled in the presence of Magnesium oxide into standard boric acid solution and titrated with standard acid.

All Gerhardt Vapodest rapid distillation units are suitable for this determination. Traditional Distillation systems are also available.


For more information on the Gerhardt Traditional Distillation Equipment – click here.

For more information on the Gerhardt Vapodest Rapid Distillation systems – click here.

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