DIN 38405-9:2011-09

Nitrate ions are present in drinking, ground, surface and waste water in various concentrations and are also contained in procedures of biological wastewater treatment plants and in certain industrial wastewater, the latter also in higher concentrations.
This standard specifies a procedure for spectrometric determination of the nitrate ion with 2,6 dimethyphenole.
The method is suitable for the determination of nitrate nitrogen in the concentration range from 0,10 mg/l to 5,00 mg/l using a 5 cm rectangular cell and from 0,5 mg/l to approximately 25,0 mg/l using a 1 cm rectangular cell. It is applicable for drinking water, ground water and slightly polluted surface or waste water.
For unknown samples or samples with higher nitrate concentrations, pre-tests using nitrate test sticks available on the market have been proven. Thus, the user will receive information about the possible measurement range prior to the photometric measurement or advance information about the necessary dilution.
This standard has been prepared by NA 119-01-03-01 UA "Allgemeine und anorganische Analytik" ("General and inorganic analytics") of NA 119-01-03 AA "Wasseruntersuchung" ("Water Analysis") at the Water Practice Standards Committee (NAW) which has been funded by the Länderfinanzierungsprogramm "Wasser, Boden und Abfall" (federal funding programme "Water, soil and waste").