EPA CTM 027

Isokinetic sampling train
Filter separates particulates from gaseous ammonia
- Typically, only the gaseous ammonia is quantified
Analyses by Ion Chromatography.

Ammonia (NH₃);
Other cations (e.g. Li, Na, K, Mg and Ca can be quantified using the analytical technique)

Charge first three collection impingers with 100 mL 0.1 N H2SO4 each;
Charge the final impinger with 300 g silica gel.
Recover each impinger separately
- Allows determination of collection efficiency;
- Analysis continues until less than 10% of the total ammonia is found in subsequent impinger catches;
Keep samples chilled after sampling
If water droplets are expected, a cyclone pre-collector should be used for separation from the sample.
- Post-sampling; The train should be purged with clean dry air to evaporate the droplets.
- This is to minimize collection of salts (e.g. sodium chloride) and/or scrubbing of acid gases onto droplets on the filter.
If high moisture content is expected, an optional pre-impinger can be inserted prior to the first two. This impinger should be charged with 50 mL of the 0.1 N H₂SO₄ absorbing solution.

The H₂SO₄ absorbing solution should be shipped as a hazardous material. Please call for IATA codes if you need them.
Samples must be shipped at chilled (5^oC) temperatures.
Be sure to include a chain of custody for each shipping container.

This method is an excellent diagnostic tool for determining the efficacy of an SCR's catalyst bed and ammonia injection (slip);
Although it is not a promulgated test method, it is currently the EPA's only viable test method for ammonia emissions;
Clean Air can bring an Ion Chromatograph into the field for very quick (same day) results.