Method SM 4500-NH3 D

Ammonia by Selective Electrode

This method is for the determination of ammonia in drinking, surface and wastewater. The working range of the method is 0.03 to 1400 mg NH3-N/L. Dissolved ammonia is converted to aqueous ammonia, NH3(aq) by raising the pH to above 11 with a strong base. Analysis is performed with an ammonia-selective electrode which uses a hydrophobic gas-permeable membrane to separate the sample solution from an electrode internal solution of ammonium chloride. High concentrations of dissolved ions will affect the measurement of ammonia but color and turbidity do not affect the analyses.

(Standard Methods)


No Obligation Quotation for Analytical Services

If you would like us to provide a quote for laboratory analysis, just provide us with as much information as you can about your project (the more, the better) and we'll provide you a quote via email. As you are searching or browsing our Analytical Guide, you'll see the Request-A-Quote icon... just click on it to start the request process.

Method Data

Hold Times, Preservatives, Preps, Collection, Analytical & Documentation
Holding Time:   28 days from sample collection to analysis if the sample is acidified or frozen. 24 hours from sample collection to analysis if the sample is refrigerated.
Preservatives:   Refrigerate at 4°C for samples to be analyzed within 24 h. pH < 2 with concentrated H2SO4 for samples high in organic and nitrogenous matter, and for longer storage longer than 24 hours.
Required Preps:   500 mL amber glass bottle with a Teflon-lined lid
Collection Method:   Grab sampling
Analytical Methodology:   Ammonia selective electrode
Documentation:   SM 4500 NH3 D

Analyte List*

Analyte Formula CAS Number Detection Limit

* The analytes and detection limits listed for each method represent the typical detection limits and analytes reported for that particular method. Keep in mind that analyte lists may vary from laboratory to laboratory. Detection limits may also vary from lab to lab and are dependent upon the sample size, matrix, and any interferences that may be present in the sample.