Brian CornwellJason Freischlag

Longwood University

CHEM 351Starlight Lane Tire Fire Superfund SiteRoanoke, VA04/26/13

History

• This site has been used as a tire dump for over 40 years. There have been over 20 major fires. The site contains roughly 5 million tires.

• According to superfund documents the site has been run by Mr. W. Keeling whom picks up tires from local businesses and burns them.

Background

• According to an EPA report from 2002 the site would require 12 months of work and up to $2 million to clean up. (1)

• Site is located a quarter mile from an elementary school, a mile from a high school, and in the middle of neighborhoods.

Contaminants

• Some air pollutants released include SO2, CO, toluene, styrene, and xylene.

C OS

O O

Previous Techniques

• Carbon monoxide detectors have been installed in nearby houses.

• Because CO is colorless, odorless, and toxic, these detectors are important for early detection.

Pyrolitic Oil

• Tar-like substance resulting from the burning of tires

• Breaks down in soil into polyaromatic hydrocarbons.

• Because these toxic polyaromatic hydrocarbons can get into well water and other water sources, these are the compounds of interest (particularly benzo(a)pyrene).

Characteristics of Benzo(a)pyrene (2)

• Group 1 carcinogen• High boiling point and melting point• Non-volatile• Nonpolar• UV active• Solid• Organic

• Because of these characteristics, GC is not useful for testing.

HPLC

• PAH can be best extracted in benzene and can be analyzed with multiple techniques (GC, LC, mass spec), but HPLC offers best results. (3)

• HPLC delivers quick, replicable quantitative and qualitative results.

• This situation calls for NP-HPLC (normal phase) because the analyte is nonpolar.

• The column should be long and thin for increased number of theoretical plates and therefore better resolution.

HPLC Diagram (4)

• 1) Solvent reservoirs, 2) Solvent degasser, 3) Gradient valve, 4) Mixing vessel for delivery of the mobile phase, 5) High-pressure pump, 6) Switching valve in "inject position", 6') Switching valve in "load position", 7) Sample injection loop, 8) Pre-column (guard column), 9) Analytical column, 10) Photodiode Array Detector (UV), 11) Data acquisition, 12) Waste

Sample Preparation (5)

• Soil samples are dissolved in benzene and solid phase microextraction (SPME) is used to remove analyte from soil matrix.

• Benzene is an excellent solvent because it is cheap, nonpolar, and stable.

Detector

• Photodiode Array (PDA) is an ideal detector for this situation because it is selective for analytes in the UV range, is cheap, and the most common detector for HPLC.

• The ideal wavelength to detect Benzo(a)pyrene is 254 nm, but at 295 nm, the interference peak is decreased, giving better quantitative results.

• With this in mind, a D2 arc lamp or Xe arc lamp would be an ideal source because of their wavelength range (190-400 nm and 140-2,000 nm, respectively.)

Conclusion

• This technique offers quantitative results based on the area under the peaks.

• It offers qualitative results based on standards that are run under exact conditions.

• HPLC is a perfect technique to analyze this site because of its sensitivity. The PAH is not found in nature so any amounts of it are harmful.

• There are documented results of this technique working with similar sites and all components of the HPLC are standard practice.

References

• 1. United States Environmental Protection Agency. "Approval of a Request for Funds for a Removal Action at Starlight Lane Tire Fire Site." (2002): 1-12. Print.

• 2. Buha, Aleksandra. "Polycyclic Aromatic Hydrocarbons." Toxipedia.org. N.p.: n.p., n.d. Polycyclic Aromatic Hydrocarbons. 09 May 2011. Web. 26 Apr. 2013. <http://toxipedia.org/display/toxipedia/Polycyclic%20Aromatic%20Hydrocarbons>.

• 3. Khopar, S.M. Environmental Pollution: monitoring and control. New Delhi: New Age International (P) Ltd, 2004. pg 179 Print.

References (cont’d)

• 4) "File: HPLC Apparatus.svg." Wikipedia. Wikimedia Foundation, 15 Jan. 2009. Web. 26 Apr. 2013. <http://en.wikipedia.org/wiki/File:HPLC_apparatus.svg>.

• 5) Vas, György, and Károly Vékey. "Solid-phase Microextraction: A Powerful Sample Preparation Tool Prior to Mass Spectrometric Analysis." Journal of Mass Spectrometry 39.3 (2004): 233-54