EPA Method 353.3

ALS - Columbia offers EPA Method 353.3 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

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EPA Method 353.3:
Nitrate-Nitrite by Cadmium Reduction and Colorimetry. Official Name: Nitrogen, Nitrate-Nitrite (Spectrophotometric, Cadmium Reduction)

Nitrate and nitrite: A filtered sample is passed through a column containing granulated copper-cadmium to reduce nitrate to nitrite. The nitrite (originally in the sample and reduced nitrate) is determined by diazotizing with sulfanilamide and coupling with N-(1-naphthyl)-ethylenediamine dihydrochloride to form a highly colored azo dye, which is measured with a spectrometer.Nitrite alone: The procedure is the same except that the cadmium column is bypassed.

This method determines nitrite singly or nitrate and nitrite combined 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) Suspended matter: Suspended materials will fowl the reduction column and restrict sample flow. Pretreat by filtering the sample through a 0.45 um filter or (for highly turbid samples) pretreating with zinc sulfate before filtration.(B) Metals: Metals like iron or copper can produce low results. Treat samples with EDTA to remove this interference.(C) Oil and grease: Oil and grease, that can coat the column and reduce efficiency should be removed by pre-extracting the sample with an organic solvent.

QC Requirements:

Maximum Holding Time:
28 Days (nitrate+nitrite)48 hours (nitrate or nitrite, singly)(MCAWW, Table 1).



0.01 to 1.0 mg/L Nitrate-nitrite nitrogen.

Sample Prep:

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


Revision Number:
Issued 1974

Test Description:
Nitrate-Nitrite (as

Report Number:

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Examples:  8260

Examples:  Dioxin
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