Ozone Precursors

Ozone is of primary concern to the USEPA in its latest promulgation to the Clean Air Act, especially ozone’s presence in metropolitan areas.  The emission of hydrocarbons (ozone precursors) from vehicles and industrial sources is the leading cause of man-made production of ozone.  The photo reactivity of specific hydrocarbons can vary greatly, e.g. most olefins and aromatic hydrocarbons contribute more to this process than do paraffins.  Therefore, speciation and quantification of these hydrocarbon components is critical in the determination of potential ozone production by the source.

The identification and quantification of low-level hydrocarbons is a daunting task due to the large variability in sample concentrations, and the wide range in boiling points from C2 compounds up to the C13 isomers.

Air Technology offers a GC/MS method that can provide low ppbv detection limits for a list of analytes typical of the ozone precursors.  The analyte list can be expanded and the method can be tailored to use a GC/FID methodology.

Table 1  table lists the analytes and reporting limits (RLs) for ozone precursors for standard analysis.