EPA Method 350.2

ALS - Columbia offers EPA Method 350.2 testing at these laboratories:

Kelso Kelso, Washington Laboratory

Method information displayed is provided for informational purposes only. No warranty (express or implied) is made as to the website accuracy, completeness, or applicability (such as the age of a method and whether or not it applies to your project). Please contact us for assistance. Analytical testing dots

PDF IconView Actual EPA Method 350.2 (PDF File)

EPA Method 350.2:
Ammonia by Colorimetry (Nesslerization). Official Name: Nitrogen, Ammonia (Colorimetric; Titrimetric; Potentiometric - Distillation Procedure)

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 colorimetrically by Nesslerization, or by other options given in the method.

This method determines ammonia, exclusive of Kjeldahl nitrogen, in drinking, surface, and saline waters; domestic and industrial wastes.

Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)

(A) Compounds 1: Many aromatics, aliphatic amines, and other compounds can cause turbidity upon reaction with Nessler reagent. Distillation is used prior to analysis to reduce/eliminate interferences.(B) Compounds 2: Volatile alkaline compounds (some ketones, aldehydes, and alcohols) can effect Nesslerization. Some compounds (e.g., formaldehyde) can be removed prior to to distillation by boiling off at low pH.(C) Cyanate: Cyanate can hydrolyze during distillation.(B) Residual Chlorine: Remove residual chlorine using sodium thiosulfate.

QC Requirements:

Maximum Holding Time:
28 days (MCAWW, Table 1).



0.05 - 1.0 mg/L ammonia as nitrogen (colorimetric)

Precision and accuracy values were calculated using interlaboratory data from EPA-managed Water Pollution (WP) performance evaluation studies.


Revision Number:
Editorial Revision 1974

Test Description:
Ammonia (as N) -Colo

Report Number:

Instrument used for this test:

Analytical testing dots
At least 1 analytes can be tested by ALS - Columbia using EPA Method 350.2. Please contact us for all available analytes which can be tested by EPA Method 350.2.

AnalyteCAS Number
Ammonia as Nitrogen7664-41-7

Examples:  8260

Examples:  Dioxin
Analytical testing dots

<-- Search All Test Methods

Suggestions? The test methods page continues to expand and improve. If you have suggestions for improvement, we would enjoy hearing from you. Please contact the webmaster here.

Analytical testing dots