This International Standard specifies a method for the determination of nitrite(N) (see note 2), nitrate(N) or the sum of both [nitrite/nitrate(N)], in various types of waters (such as ground, drinking, surface, and waste waters) in mass concentrations ranging from 0,01 mg/l to 1 mg/l for nitrite(N) and from 0,2 mg/l to 20 mg/l for nitrite/nitrate(N), both in the undiluted sample. The range of application can be changed by varying the operating conditions. NOTES 1 Seawater may be analysed with changes in respect to sensitivity and adaptation of the carrier solution and calibration solutions to the salinity of the samples. 2 The following concise terms are used in the text of this International Standard: nitrite(N): (mass concentration of) nitrite, expressed as nitrogen nitrate(N): (mass concentration of) nitrate, expressed as nitrogen nitrite/nitrate(N): (mass concentration of) the sum of nitrite(N) and nitrate(N)