NEMI Method Summary

Method Summary Information

Method Number: I-2525 Media: WATER
Revision: Mar-86
Method Source: U.S. Geological Survey (USGS)
Subcategory: INORGANIC Analytes in this method
Official Name: Nitrogen, ammonia, low ionic-strength water, colorimetry, salicylate-hypochlorite, automated-segmented flow
Descriptive Name Nitrogen, ammonia, dissolved, low ionic-strength, colorimetric, ASF
Source Info: USGS Branch of Information Services
Box 25286, MS 417
Federal Center
Denver, CO 80225-0286
Phone: 303-202-4700
Citation: U.S. Geological Survey Open-File Report 93-125
128829 Byte file
Brief Method
Summary:
 Ammonia reacts with hypochlorite and salicylate ions in the presence of ferricyanide ions to form the salicylic acid analog of indophenol (Reardon and others, 1966; Patton and Crouch, 1977; Harfmann and Crouch, 1989).
Scope And
Application:
 This method is used to analyze samples of precipitation and natural water containing from 0.002 to 0.30 mg/L of ammonia-nitrogen. Concentrations greater than 0.30 mg/L must be diluted. This method was implemented in the National Water Quality Laboratory in March 1986 and modified in May 1989.
Applicable
Conc Range:
 0.002 to 0.30 mg/L
Interferences: No substance found in natural water seems to interfere with this method.
The samples are easily contaminated by ammonia in the laboratory atmosphere; therefore, sample handling and analysis need to be performed where there is no possibility of ammonia contamination.
QC Requirements: Calibrate instrument using calibration standards (CAL); quality control samples (QCS); and laboratory blanks (LB) analyzed at a minimum of 1 for every 10 samples.
Sample Handling: Container Description: 125 mL brown polyethylene bottle.
Treatment and Handling: Filter through 0.45 micron filter; use filtered sample to rinse container; preservation with mercuric chloride; chilled to 4 degrees C and ship immediately.
Max Holding Time:
 30 days
 
Relative Cost: Less than $50
5480
Page 1