Presentation on theme: "Brian Cornwell Jason Freischlag Longwood University CHEM 351 Starlight Lane Tire Fire Superfund Site Roanoke, VA 04/26/13."— Presentation transcript:
Brian Cornwell Jason Freischlag Longwood University CHEM 351 Starlight Lane Tire Fire Superfund Site Roanoke, VA 04/26/13
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 SO 2, CO, toluene, styrene, and xylene.
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 D 2 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.. 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.. 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