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Sum parameter – Total Organic Carbon
TN b – total bound nitrogen
SCA-130-503
Although nitrogen compounds are essential ■ Total nitrogen TN b
for nature and the environment, high nitrogen The variety of possible nitrogen compounds
depositions can lead to problems. Nitrogen necessitated the definition of a sum
compounds enter the environment primarily parameter that represents the total nitrogen
through agricultural processes. Nitrogen- compounds. For this purpose, the so-called
containing fertilizers constitute the largest TN b (total bound nitrogen) was defined and
proportion. But nitrogen compounds can also standardized.
enter the environment via chemical industrial
processes. The TN b is the total nitrogen content of a
sample in the form of ammonium, nitrite,
Excessively high concentrations of nitrogen nitrate, as well as organic compounds. The
compounds in the environment can cause TN b does not include dissolved or gaseous
eutrophication of water bodies. Eutrophication nitrogen (N 2). A differentiation between
is the process of uninhibited growth of algae inorganic and organic nitrogen compounds is,
and other organisms due to an excess supply by definition, not possible.
of nutrients. This overgrowth results in a lack
of oxygen in the water, which can lead to fish
mortality and to the formation of aquatic dead
zones.
Bound nitrogen occurs in nearly all waters,
mostly in the form of ammonia, nitrate, nitrite
or organic compounds.
■ Determination according EN 12260
EN 12260 describes the determination of
nitrogen in the form of free ammonia,
ammonium, nitrite, nitrate and organic
compounds that can be converted under the
described oxidative conditions.
