1 Scope
This document specifies a method for the determination of nitrate as NO 3 -N in water of various origin such as natural water (including groundwater, surface
water and bathing water), drinking water and wastewater, in a measuring range of concentration
between 0,10 mg/l and 225 mg/l of N0 3 -N using the small-scale sealed tube method. Different measuring ranges of small-scale sealed tube methods can be required.
The measuring ranges can vary depending on the type of the small-scale sealed tube method of different manufacturers.
It is up to the user to choose the small-scale sealed tube test with the appropriate application range or to adapt samples with concentrations
exceeding the measuring range of a test by preliminary dilution.
NOTE 1 The results of a sealed-tube test are most precise in the middle of the application
range of the test.
Manufacturers' small-scale sealed tube methods are based on dimethylphenol colour reaction depending on the typical operating
procedure of the small-scale sealed tube used, see Clause 9.
NOTE 2 Laws, regulations or standards can require that the data is expressed as NO 3 - after conversion with the stoichiometric conversion factor 4,426 81 in Clause 11.
NOTE 3 In the habitual language...