PFOA in Teflon Coated Cookware Megan Hartmann CHEM 4101 December 9th, 2011 PFOA and Teflon • Perfluorooctanoic Acid – A carcinogen and toxicant – Synthetic compound – Molar Mass • 414.07 g/mol – Typical amount found in cookware • 4.3 ppb • Teflon – Chemically known as polytetrafluoroethylene (PTFE) – Synthetic fluorocarbon polymer – Degrades around 260°C Background • PFOA is a surfactant used to attach PTFE into cookware making it non-stick. • PFOA is removed when cookware is cured, but residual amounts can remain • If the cookware is scratched or heated to high temperatures during cooking, the residual levels can be released into the air or the food being prepared. Hypothesis By using proper analytical techniques the residual PFOA that is released when Teflon coated cookware is heated to high temperatures can be measured. Techniques Considered Techniques Advantages Disadvantages IR • PFC’s are easily differentiated between • Fast • Matrix and Solvents must be essentially nonexistent Reverse Phase HPLC • Good Selectivity • Easily reproducible • PFC’s all have different retention times • Costly • Time consuming • Requires large amounts of solvents • • • • • Newer technique without much data available • Must use HPLC and not GC Suppressed Conductivity Detection Good Selectivity Good Sensitivity Fast Inexpensive Method of Choice: GC-MS Standards: PFOA from Sigma-Aldrich Order Number:171468 PFTE from Sigma-Aldrich Order Number:430935 Figure 1: Retrieved from http://www.chromacademy.com/resolver-november2010_Understanding_GCMS_part_1.asp Agilent 7000 GC/MS • High Selectivity • Fast Analysis (500 transitions per second) • Fluorinated compounds have different retention times Figure 2: Retrieved from Agilent Technologies. (2009). Agilent 7000B Triple Quadrupole GC/MS. [Brochure]. Agilent 7000 ESI-Triple Quadrupole Mass Spectrometer • Signal to Noise Ratio of 500:1 for 100 femtograms • LOD- femtogram level • Operates at temperatures as high as 200°C • High selectivity Figure 3: Retrieved from Agilent Technologies. (2009). Agilent 7000B Triple Quadrupole GC/MS. [Brochure]. Sample Prep 1. Empty Teflon coated cookware is heated up to varying temperatures – Specifically around 200-300°C • Smoke point of oils and where Teflon degrades 2. PFTE (Teflon) must be scraped off of cookware and made into a powder 3. Internal standards of PFOA and PFTE are added Expected Results Potentially harmful levels of PFOA will be found in Teflon coated cookware upon heating to high temperature Figure 4: Typical Quadrupole Mass Spectrum for PFOA Retrieved from Begley, T. "Perfluorochemicals: Potential sources of and migration from food packaging.” Conclusion To determine the safety of Teflon coated cookware GC/MS analysis can be used to measure the levels of residual perfluorooctanoic acid which are harmful to humans. References 1. 2. 3. 4. 5. 6. 7. 8. 9. Begley, T. "Perfluorochemicals: Potential sources of and migration from food packaging." Food additives and contaminants 22.10 (2005):1023.Guo, Zhishi, and X. Liu, and K. Krebs, “Perfluorocarboxylic Acid Content in 116 Articles of Commerce.” National Risk Management Research Laboratory, Environmental Protection Agency, 2009. Huang, Ke, and KHuang. "Determination of trace PFOA in textiles with HPLC-UV spectrometry." 印染 37.9 (2011):37. Kadar, H. "Comparative study of low- versus high-resolution liquid chromatographymass spectrometric strategies for measuring perfluorinated contaminants in fish." Food additives & contaminants. Part A. Chemistry, analysis, control, exposure & risk assessment 28.9 (2011):1261. King, Anthony. "Sticking point", Chemistry and Industry. 2007, 17, 24-25 Lindstrom, Andrew, and A B BLindstrom. "Polyfluorinated Compounds: Past, Present, and Future." Environmental science & technology 45.19 (2011):7954. Lv, Gang, GLV, andLv. "Determination of perfluorinated compounds in packaging materials and textiles using pressurized liquid extraction with gas chromatographymass spectrometry." Analytical Sciences 25.3 (2009):425. Skoog, Douglas A., F. James. Holler, and Stanley R. Crouch. Principles of Instrumental Analysis. 6th ed. Belmont, CA: Thomson Brooks/Cole, 2007. Tracy, M., Liu, X., and Pohl, C. “Analysis of Perfluorooctane Sulfonate and Perfluorooctanoate in Water Samples Using Reversed-Phase Liquid Chromatography with Suppressed Coonductivity Detection.” Dionex Corporation. 2009. Agilent Technologies. (2009). Agilent 7000B Triple Quadrupole GC/MS. [Brochure].