Megan HartmannCHEM 4101

December 9th, 2011

PFOA in Teflon Coated

Cookware

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 ConsideredTechniques Advantages Disadvantages

IR • PFC’s are easily differentiated between

• Fast

• Matrix and Solvents must be essentially non-existent

Reverse Phase HPLC • Good Selectivity• Easily reproducible• PFC’s all have different

retention times

• Costly• Time consuming• Requires large amounts

of solvents

Suppressed Conductivity Detection

• Good Selectivity• Good Sensitivity• Fast• Inexpensive

• Newer technique without much data available

• Must use HPLC and not GC

Method of Choice: GC-MSStandards: 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 ResultsPotentially harmful levels of PFOA will be

found in Teflon coated cookware upon heating to high temperature

Retrieved from Begley, T. "Perfluorochemicals: Potential sources of and migration from food packaging.”

Figure 4: Typical Quadrupole Mass Spectrum for PFOA

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.

References1. 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.

2. Huang, Ke, and KHuang. "Determination of trace PFOA in textiles with HPLC-UV spectrometry." 印染 37.9 (2011):37.

3. 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.

4. King, Anthony. "Sticking point", Chemistry and Industry. 2007, 17, 24-255. Lindstrom, Andrew, and A B BLindstrom. "Polyfluorinated Compounds: Past, Present,

and Future." Environmental science & technology 45.19 (2011):7954.6. Lv, Gang, GLV, andLv. "Determination of perfluorinated compounds in packaging

materials and textiles using pressurized liquid extraction with gas chromatography-mass spectrometry." Analytical Sciences 25.3 (2009):425.

7. Skoog, Douglas A., F. James. Holler, and Stanley R. Crouch. Principles of Instrumental Analysis. 6th ed. Belmont, CA: Thomson Brooks/Cole, 2007.

8. 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.

9. Agilent Technologies. (2009). Agilent 7000B Triple Quadrupole GC/MS. [Brochure].