Methodology | EPA1 | Standard Methods (20th edition) | ASTM | USGS2 | Other | ||
Manual distillation at pH 9.54, followed by: | 350.2 | 4500-NH3 B | 973.493 | ||||
Titration | 350.2 | 4500-NH3 C | |||||
Manual electrode | 350.3 | 4500-NH3 D or E | D1426-93(B) | ||||
Automated phenate | 350.1 | 4500-NH3 G | 1-4523-85 | ||||
Automated electrode | See note5 | ||||||
1"Methods for Chemical Analysis of Water and Wastes," Environmental Protection Agency, EPA-600/4-79-020, Revised March 1983 and 1979 where applicable.
2Fishman, M.J., et al., "Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments," U.S. Department of the Interior, Techniques of Water-Resource Investigations of the U.S. Geological Survey, Denver, CO, Revised 1989, unless otherwise stated.
3"Official Methods of Analysis of the Association of Official Analytical Chemists," 15th edition, 1990.
4Manual distillation is not required if the samples are very low in turbidity; however, manual distillation should be used whenever matrix interferences could be present in the sample, and will be required to resolve any controversies.
5Ammonia, Automated Electrode Method, Industrial Method Number 379-75 WE, dated February 19, 1976, Bran & Luebbe (Technicon) Auto Analyzer II, Bran & Luebbe Analyzing Technologies, Inc., Elmsford, NY 10523.
Iowa Admin. Code r. 567-41.11