EPA-NERL: 350.2 (Titration):  Ammonia by Titrimetry

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
 Nitrogen, Ammonia (Colorimetric; Titrimetric; Potentiometric - Distillation Procedure)
Current Revision
Editorial Revision 1974
Media
 WATER
Instrumentation
 Titration
Method Subcategory
 Inorganic
Method Source
  EPA-NERL
Citation
  Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)
Brief Method Summary
 A sample is buffered at alkaline pH with borate buffer to decrease hydrolysis of cyanates and organic nitrogen compounds, and is distilled into a solution of boric acid. The ammonia distillate is determined using a colorimetric titration, or by other options given in the method.
Scope and Application
 This method determines ammonia, exclusive of Kjeldahl nitrogen, in drinking, surface, and saline waters; domestic and industrial wastes.
Applicable Concentration Range
 1.0 - 25 mg/L ammonias nitrogen (titrimetric)
Interferences
 (A) Cyanate: Cyanate can hydrolyze during distillation.
(B) Residual Chlorine: Remove residual chlorine using sodium thiosulfate.
Quality Control Requirements
 None.
Sample Handling
 Cool to 4oC, add H2SO4 until sample pH < 2.
Maximum Holding Time
 28 days (MCAWW, Table 1).
Relative Cost
 Less than $50
Sample Preparation Methods
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