ASTM D1426

Full Name

ASTM D1426 – Standard Test Methods for Ammonia Nitrogen In Water


These test methods cover the determination of ammonia nitrogen, exclusive of organic nitrogen, in water.

Two test methods are included:

  • Test Method A – Direct Nesslerization
  • Test Method B – Ion Selective Electrode

Test Method A is used for the routine determination of ammonia in steam condensates and demineralizer effluents.

Test Method B is applicable to the determination of ammonia nitrogen in the range from 0.5 to 1000 mg NH3N/L directly in reagent and effluent waters. Higher concentrations can be determined following dilution. The reported lower range is based on multiple-operator precision. Lower limits have been obtained by two of the twelve laboratories participating in the round robin.


ammonia nitrogen; water; direct nesslerization; ion selective electrode