Leeder Consulting specialist laboratory services



air analysis services
>> environmental analytical services > air analysis > ambient trace organics > pahs by usepa to13a
 
PAHs by USEPA TO-13A  
METHOD TO-13A Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Ambient Air Using Gas Chromatography/Mass Spectrometry (GC/MS) .

Polycyclic aromatic hydrocarbons (PAHs) have received increased attention in recent years in air pollution studies because some of these compounds are highly carcinogenic or mutagenic. In particular, benzo[a]pyrene (B[a]P) has been identified as being highly carcinogenic. This method describes a sampling and analysis procedure for common PAHs involving the use of a combination of quartz filter and sorbent cartridge with subsequent analysis by gas chromatography with mass spectrometry (GC/MS) detection.

The choice of GC/MS as the recommended procedure for analysis of B[a]P and other PAHs was influenced by its sensitivity and selectivity, along with its ability to analyze complex samples.

nata accreditation and iso nata certified
PUF cartridges are the preferred primary sorbent as they are easier to handle in the field and maintain better flow characteristics during sampling. Likewise, PUF has demonstrated its capability in sampling organochlorine pesticides, polychlorinated biphenyls, and polychlorinated dibenzo-p-dioxins.

This method includes the qualitative and quantitative analysis of the following PAHs specifically by utilizing PUF as the sorbent followed by GC/MS analysis:

Acenaphthene, Coronene, Dibenz(a,h)anthracene, Acenaphthylene, Fluoranthene, Fluorene,Anthracene, Benzo(b)fluoranthene, Benz(a)anthracene, Indeno(1,2,3-cd)pyrene, Benzo(a)pyrene, Naphthalene, Benzo(e)pyrene, Benzo(g,h,i)perylene, Phenanthrene, Benzo(k)fluoranthene, Pyrene, Chrysene, Perylene.

The GC/MS method is applicable to the determination of PAHs compounds involving three member rings or higher. Naphthalene, acenaphthylene, and acenaphthene have only ~35 percent recovery when using PUF as the sorbent. Nitro-PAHs have not been fully evaluated using this procedure; therefore, they are not included in this method. With optimization to reagent purity and analytical conditions, the detection limits for the GC/MS method range from 1 ng to 10 pg based on field experience.

Summary of Method
Filters and sorbent PUF® cartridges are installed in the sampler.

Approximately 300 m of air is drawn through the filter and sorbent cartridge using a high-volume flow rate air sampler or equivalent. The amount of air sampled through the filter and sorbent cartridge is recorded, and the filter and cartridge are placed in an appropriately labeled container and shipped along with blank filter and sorbent cartridges to the laboratory for analysis.

The samples and the blanks are analyzed and used (along with the amount of air sampled) to calculate the concentration of PAHs in the air sample.