Megan Hartmann-Analytical Problem- PFOA and Teflon
Polytetrafluoroethene, commonly known as Teflon, is a polymer that is used in many pots and pans today to make them non-stick. To create Teflon coated pans many companies will use compounds called perfluorooctanoic acid, or PFOA, to act as a surfactant to the Teflon. It has recently been discovered that PFOA is a carcinogenic and persists in the environment for many years. Although most of the PFOA is burnt off when the pans are cured at high temperatures there are still small levels that are given off during the first few times the pans are used. As the pans used small defects can become another source of PFOA's entering the air and the food that is being cooked at the time. Due to the nature of Teflon, it is very easy to scratch pans and cause tiny defects that could later lead to PFOA entering the body or environment. Many companies have said they will no longer use PFOA's by 2015 but will continue to use Teflon. This also causes problems because when Teflon reaches certain temperatures (250oC) it begins to break down and releases a compound similar to PFOA.
UV-Vis absorption spectrometry
Teflon does not absorb in the UV-VIS range due to the fluorine in the compound. The fluorines cause Teflon to have a large band gap and would therefore require a high energy to excite the electrons. PFOA also has a low UV-VIS absorption for the same reason. To use UV-VIS absorption to detect a derivatization of PFOA must occur. One way to do this is by adding benzylamine in N2¬ and xylene using the catalyst Al2¬O3. The solution was then heated at 140°C for ten hours. The derivative was found to absorb at 248 nm or higher and had a molar absorption coefficient of 103.(2) There are not many papers found on UV-VIS absorption for PFOA and Teflon because other methods are more promising for determining if they are present such as LC/MS.(3)
Similar Analytical Problem
One analytical problem similar to mine is DEHP Leaching from PVC into Contents of Medical Devices from Rajvi Mehta. Our problems are similar because they are both polymers leaching out of other substances. Both PFOA and DEHP are detrimental to humans at high levels. Both problems have similar issues when it comes to setting up studies and tests for our analytes. Such as mine there are easily ways to get both positive and negative controls whereas hers, it may be hard to find a negative control.
Chemical Structures and Standards
From Sigma-Aldrich, 171468, 5g for $34 or 25g for $130
From Sigma-Aldrich, 430935, 5g for $35.40 or 100g for $130
Mass Spectrum using ESI-triple Quad
Kadar, H. "Comparative study of low- versus high-resolution liquid chromatography-mass spectrometric strategies for measuring perfluorinated contaminants in fish." Food additives & contaminants. Part A. Chemistry, analysis, control, exposure & risk assessment 28.9 (2011):1261.
1.King, Anthony. "Sticking point", Chemistry and Industry. 2007, 17, 24-25
2.Lindstrom, Andrew, and A B BLindstrom. "Polyfluorinated Compounds: Past, Present, and Future." Environmental science & technology 45.19 (2011):7954.
3.Huang, Ke, and KHuang. "Determination of trace PFOA in textiles with HPLC-UV spectrometry." 印染 37.9 (2011):37.