June 2009
Front Matter
Training
43
Air Toxics Sampling and Analysis (1 of 2)
•Because air toxics are present in the atmosphere in gaseous, particulate, and semi-volatile form, no single measurement technique is adequate.
•EPA offers 17 approved sampling and analysis methods for toxic gases; among the most commonly used methods are the following:
–Compendium method TO-11A.  Used to measure formaldehyde and other carbonyl compounds. 
–Compendium method TO-13A.  Used to measure Polycyclic Aromatic Hydrocarbon (PAH) compounds. 
–Compendium method TO-15.  Created to target 97 compounds on the list of 187 hazardous air pollutants.
Differences in chemical and physical properties further complicate collection; the choice of measurement technique depends on the objectives of data collection, including the chemical species of interest, funds available, and desired detection limit
Previous methods include TO-5 which had lower sensitivity and reproducibility and was more labor-intensive.  Method TO-11A uses coated dinitrophenylhydrazine (DNPH) cartridges to collect the samples and analyzes them using high performance liquid chromatography (HPLC).
TO-13A allows for a variety of sampling media; an effective choice is the combination of polyurethane foam (PUF) and XAD-2®.  Samples are analyzed by high resolution gas chromatography/mass spectrometry (GC/MS).
TO-15 uses specially prepared canisters analyzed by high resolution gas chromatography/mass spectrometry (GC/MS).