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Posts Tagged ‘PAH in Shellfish’

PAH Analysis: Expanded Compounds of Concern and Advancements

Wednesday, September 5th, 2012

By Lee Wolf, Regulatory Affairs Manager, ALS Environmental – USA

As a class of organic compounds, PAHs are characterized by bonded aromatic rings that do not typically carry other functional groups or branched groups substituted for hydrogen atoms. PAHs occur in fossil fuel materials such as oil, coal, tar and fuels. They are produced as a result of fuel burning. They are also found in products such as burned tobacco, incense, and some plant-based oils. To further understand the sources of PAHs, they may be classified as follows:

  • Petrogenic – These are PAHs derived from petroleum inputs and generally associated with fossil fuels.
  • Pyrogenic – These are PAHs which are derived from combustion sources.
  • Biogenic – These are PAHs formed from natural biological processes.

The toxicity of PAHs is dependent upon the structure or arrangement of aromatic rings. For example, the toxicity of some PAH isomers (with the same formula and number of rings) can vary from being effectively nontoxic to being very toxic. The more toxic or carcinogenic PAHs may be small or large. The USEPA has identified seven PAH compounds as probable human carcinogens.

Read more about PAH Analysis…

Polycyclic Aromatic Hydrocarbons (PAH) in Shellfish

Friday, May 28th, 2010

Polycyclic Aromatic Hydrocarbons (PAH) in Shellfish

Columbia Analytical Services, Inc. has extensive experience testing for low levels of Polycyclic Aromatic Hydrocarbons (PAH) in shellfish. Sensitive and selective techniques were developed over ten years ago and have been refined and improved on a continuing basis. In addition to the analysis for the common parent compounds, levels of the associated alkylated homologs can also be determined.

This analysis is typically performed using Gas Chromatography/Mass Spectrometry (GC/MS) operated in the Selective Ion Monitoring (SIM) mode. Key to the analytical procedure is proper sample preparation, which begins with shucking, compositing (as appropriate to the project plan), and homogenization via mechanical mixing. The preliminary preparation must be performed under clean laboratory conditions to prevent common PAH contamination. Decontamination of sample preparation equipment is performed and monitored closely to assure clean conditions. The sample homogenate is a homogenous slurry when prepared correctly. The homogenization techniques performed by Columbia Analytical have been inspected and approved by various organizations (e.g. US EPA, other federal government and state regulatory agencies, private industries, consultants, etc.) The data results for these projects were subjected to thorough government, public and private scrutiny.