1 / 12

Bioaccumulation of Decamethylcyclopentasiloxane

Bioaccumulation of Decamethylcyclopentasiloxane. Melissa Eubanks Chem 4101 December 9, 2011. The Problem. Silicones are widely used in the personal care and cosmetics industry Studies suggest D 4 potentially toxic 1 D 5 replaced D 4 in personal care products

briar
Télécharger la présentation

Bioaccumulation of Decamethylcyclopentasiloxane

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bioaccumulation of Decamethylcyclopentasiloxane Melissa Eubanks Chem 4101 December 9, 2011

  2. The Problem • Silicones are widely used in the personal care and cosmetics industry • Studies suggest D4 potentially toxic1 • D5 replaced D4 in personal care products • Residual levels present in derivatives made from them D4 D5

  3. Importance of Solving the Problem: • Many companies worry about going silicone free • Influence product performance and cost • Regulate the use of silicones in personal care products • Stop possible effects on environment • Hypothesis: • Decamethylcyclopentasiloxane (D5) is being washed from skin and hair and bioaccumulating in aquatic life.

  4. Experimental Design • Preparing Sediment for Analysis as raw extract3: • Top layer undisturbed sediment collected • Extraction by Sedimentation • Centrifugation • Liquid phase separated from solid • Extraction and centrifuge repeated with remaining solid phase • Liquid phases combined • Wash liquid phases • Centrifugation • Liquid phase separated from any remaining large particles

  5. Preparing Fish Samples • Rinse, wrap and seal in bags, freeze at -17°C • Frozen dorsal fillet • Cold solvent extraction • Centrifuge and repeat extraction • 4mL acetone, 2mL n-hexane • Addition on 20mL water and 0.1g sodium chloride • Centrifugation for 10min • Inject sample into GC/MS

  6. GC/MS 2

  7. Description of Instrument • Gas Chromatography coupled with Mass Spectrometry • Trace GC Ultra • MD800 MS detector • Electron Ionization • Splitless injector with microseal septum • 5µL sample injection • Injector temperature of 220°C • Carrier Gas: Helium

  8. Gas Chromatography • Decamethylcyclopentasiloxane • Mass: 370.77g/mol • BP: 210°C • Volatile compound • Requires small samples • Separating complex mixtures • Very high precision • Sensitive to detect volatile organic mixtures of low concentrations

  9. Mass Spectrometry • Quadrupole MS Analyzer • Fast scan rate • Inexpensive • Easily interfaced to • other Ionization • Methods • Electron Ionization 5

  10. Conclusion • GC/MS best technique for quantitation of D5 • Multimedia Bioaccumulation Factor (mmBAF) • Future Studies • Larger sampling area • Bioaccumulative in air breathing marine mammals • Complex bioaccumulation regulations

  11. References 1.)  Reisch, M. Storm Over Silicones. C&EN Northeast News Bureau 2011, 89, pp 10-13. 2.) Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis, 6th ed., Thomson Brooks/Cole: Belmont, 2007. 3.)  Kierkegaard, A.; van Egmond, R.; McLachlan, M. S; Cyclic Volatile Methylsiloxane Bioaccumulation in Flounder and Ragworm in the Humber Estuary. Environmental Science and Technology. 2011, 5936-5942. 4.) Kierkegaard, A.; van Egmond, R.; McLachlan, M. S; Determination of Cyclic Volatile Methylsiloxanes in Biota with a Purge and Trap Method. Anal. Chem. 2010, 82, 9573-9578. 5.) Pickering, G.; Oliff, C.; Rutt, K., The Mass Spectrometric Behavior of Dimethylcyclosiloxanes. Organic Mass Spectrometry. 1975, 10, 1035-1045. 6.)http://www.sigmaaldrich.com/catalog/ProductDetail.do?D7=0&N5=SEARCH_CONCAT_PNO|BRAND_KEY&N4=444278|ALDRICH&N25=0&QS=ON&F=SPEC 7.)http://www.spexcertiprep.com/products/product_organic.aspx?part=S-1110 8.) Almond, M. Becerra, R. Bowes, S. Cannady, J. Ogden, S. Young, N and Walsh R. A Mechanistic Study of the Low Pressure Pyrolysis of Linear Siloxanes. Physical Chemistry Chemical Physics. 2008, 11, 6856-6861

More Related