Method 16A

Determination of Total Reduced Sulfur emissions from stationary sources (impinger technique)

This method is applicable for the determination of emissions of  Total Reduced Sulfur emissions (TRS) from recovery boilers, lime kilns, and smelt dissolving tanks at kraft pulp mills, reduced sulfur emissions (hydrogen sulfide, carbonyl sulfide, carbon disulfide) from sulfur recovery units at onshore natural gas porcessing facilities, and other sources that are covered in applicable regulations.  Samples are analyzed by barium-thorium titration as in EPA Method 6.

Sulfur reacts with metal and can bias results, therefore, all components of the sampling train need to be Teflon or Teflon lined.  Components of the sampling train include a probe, filter, three SO2 scrubbers (impingers) in series and a series of four impingers.  The first two SO2 scrubbers are filled with a citrate buffer solution and the third left empty.  The citrate buffer solution should be replaced after each run as these scrubbers selectively remove SO2 from the flue gas.  The first two impingers following the SO2 scrubbers should contain a 3% hydrogen peroxide solution, the third impinger is empty and the fourth impinger contains silica gel.  

Note that the flue gas must contain at least 1% oxygen for complete oxidation of all TRS to SO2.  TRS is then thermally oxidized to SO2 which is collected in the hydrogen peroxide impingers as sulfate ion.  When sampling is completed, the hydrogen peroxide contents for each sample run are combined in a polyethylene bottle,  the impingers are rinsed with water which is combined with the impinger contents and sent to the laboratory for analysis.

The oxidation process is non-discriminating and will oxidize other reduced sulfur compounds that are present in the gas.  These compounds will also be converted to SO2 and cause a positive bias in the results.   The Teflon filter in the sampling train is needed to remove the particulates which can cause a bias in the sample results.

(EPA 40CFR Part 60 Appendix A)


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:   None specified in method.
Preservatives:   None specified in method.
Required Preps:   Teflon filter
Collection Method:   Sampling train following Method 16A procedures.
Analytical Methodology:   Barium-thorium titration following EPA Method 6
Documentation:   16A

Products You Might Need

SKU Item Price
M16A EPA Method 16a Basic Stack Sampling System $ Call for Price

Analyte List*

Analyte Formula CAS Number Detection Limit
Carbonyl sulfide
Dimethyl disulfide
Methyl mercaptan
Carbon disulfide
Dimethyl sulfide
Hydrogen sulfide

* 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.