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Posts Tagged ‘PAH’

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.

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Naphthalene Air Sampling from Manufactured Gas Plants

Wednesday, October 29th, 2008

Naphthalene is a contaminant of concern at former Manufactured Gas Plant (MGP) and other property redevelopment sites across the country. A major component of coal tar waste and a possible human carcinogen (EPA Group C), naphthalene is a chemical that may adversely affect human health at remediation sites. Due to its boiling point and vapor pressure, naphthalene can exhibit both volatile and semi-volatile characteristics; therefore the question can arise as to how to properly measure naphthalene in ambient air.

Two commonly applied methods of measuring vapor phase naphthalene include EPA Method TO-15, which utilizes whole air sampling in passivated stainless steel canisters; and EPA Method TO-13A, which utilizes high volume sorbent based sampling with polyurethane foam/XAD resin cartridges. Analytical differences between these two methods will be discussed, keeping reference to naphthalene’s unique chemical & physical properties.

This case study will present weekly data spanning a twelve month period (December 2006 – December 2007) from co-located EPA Method TO-15 and TO-13A ambient air samples at the perimeter of two MGP cleanup remediation sites. Distinct trends are noted and discussed in this paper when comparing the concentration results from the two methods.

Read the complete naphthalene air sampling case study… (Acrobat PDF)