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Polychlorinated D ibenzo-p-dioxin Analysis from P hotodegradation of T riclosan

Polychlorinated D ibenzo-p-dioxin Analysis from P hotodegradation of T riclosan. Jason Brennan Chem 4101, Fall 2010 December 10 th , 2010. Triclosan. Common antimicrobial agent used in hand soaps and hygienic products Estimated release of 22 metric tons per year into US waters[1]

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Polychlorinated D ibenzo-p-dioxin Analysis from P hotodegradation of T riclosan

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  1. Polychlorinated Dibenzo-p-dioxin Analysis from Photodegradation of Triclosan Jason Brennan Chem 4101, Fall 2010 December 10th, 2010

  2. Triclosan • Common antimicrobial agent used in hand soaps and hygienic products • Estimated release of 22 metric tons per year into US waters[1] • Can become chlorinated from chlorine in wastewater transport or disinfection and photodegrade into polychlorinatedibenzo-p-dioxins (PCDDs) • Photolytic half-lives of approx. 1 day during Summer months[1] http://www.dialsoap.com/liquid_hand_soap.html

  3. Analytes (PCDDs) 1,2,8- and 2,3,7-trichlorodibenzo-p-dioxin (TCDD) 1,2,3,8-tetrachlorodibenzo-p-dioxin (TeCDD) • Estimations are 1.06 μg/L in US waterways [1] • Half-lives in humans range from 3-8 years [2] • Concentrations of 2.5 μg/L have been shown to cause developmental defects in aquatic life [3]

  4. PCDD Detection Problem Problem: • Polychlorinated dibenzo-p-dioxins are hypothesized to be carcinogenic compounds and the 1,2,8- 2,3,7- and 1,2,3,8-PCDDs are hypothesized to be photodegredation products of triclosan Hypothesis: • Micellarelectrokinetic chromatography modified with γ-cyclodextrin with UV absorbance detection can be used to detect the analytes in river water samples.

  5. MicellarElectrokineticChromotography • Reasons: • Micelles allow for neutral species detection • γ-cyclodextrin modification increases sensitivity • Relatively low cost/sample • Quick sample runs Swiss Laboratory for Doping Analyses [4]

  6. Instrumentation • Agilent 7300 CE • Cost: $50,000 • Instrument Parameters[5] • Fused silica capillary • 40 cm effective length • 50 μm I.D. • 375 μm O.D. • 15 kV applied voltage • UV photo diode array detector (225 nm) • “Z” cell path length for increased sensitivity • 10 °C • LOD 0.1 ppm (S/N=3) • Dynamic Range • 0.3 ppm-500 ppm

  7. Sample Preparation Aqueous Sample [1] Buffer solutions [5] • 5 ml aqueous river samples extracted into n-hexanes or cyclohexane • Solvent extracted into methanol • Concentrated to minimal volume for instrumental analysis • 100 mMSodioumdodecyl sulfate • 50 mMγ-cyclodextrin • 5 M urea • pH buffer • 50 mM borate (pH=9.0) • 50 mM phosphate (pH=2.5) Stock solutions of chlorinated dioxins for calibration curves and spiking can be obtained from Sigma-Aldrich Buffer solutions can be purchased from Agilent

  8. Acidic SRW-CD-MEKC • SRW – stacking using reverse migrating micelles and a water plug • Requires low conductivity matrix with surfactant concentration slightly higher than critical micelle concentration • Water plug with low pH is injected into the capillary followed by the sample solution • Allows for 200 times lower LOD than CD-MEKC (20 ppm down to 0.1 ppm)

  9. Sample Data[5] Normal CD-MEKC SRW-CD-MEKC

  10. Conclusion • SRW-CD-MEKC allows for decreased retention time of PCDDs and dynamic range is lowered to levels predicted in river samples • MEKC analysis allows for reasonably priced quantitative analysis of these environmental pollutants • Once these PCDDs have been confirmed in river water samples further analysis could be done to determine degradation pathway using SRW-CD-MEKC method of detection

  11. Other Potential Methods

  12. References • [1]Buth, J.M., Grandbois, M., Vikesland, P.J.*, McNeill, K.*, Arnold, W.A. 2009. Aquatic photochemistry of chlorinated triclosan derivatives: potential source of polychlorodibenzo-p-dioxins. Environ. Toxicol. Chem., 28(12) 2555-2563 • [2] Geyer HJ, Schramm KW, Feicht EA, et al (2002). "Half-lives of tetra-, penta-, hexa-, hepta-, and octachlorodibenzo-p-dioxin in rats, monkeys, and humans—a critical review". Chemosphere 48 (6): 631–44. • [3]Tisha C. King Heiden, Jan Spitsbergen, Warren Heideman, and Richard E. PetersonPersistent Adverse Effects on Health and Reproduction Caused by Exposure of Zebrafish to 2,3,7,8-Tetrachlorodibenzo-p-dioxin During Early Development and Gonad DifferentiationToxicol. Sci. (2009) 109(1): 75-87 • [4] Swiss Laboratory for Doping Analyses. http://www.doping.chuv.ch/en/lad_home/lad-prestations-laboratoire/lad-prestations-laboratoire-appareils/lad-prestations-laboratoire-appareils-ec.htm . Accesses Dec. 6 2010. • [5] Koji Otsuka, Hirofumi Hayashibara, Sumio Yamauchi, Joselito P. Quirino, Shigeru Terabe, Highly-sensitive micellarelectrokinetic chromatographic analysis of dioxin-related compounds using on-line concentration, Journal of Chromatography, Volume 853, Issues 1-2, 20 August 1999, Pages 413-420 • [6] http://www.chem.agilent.com/en-US/Products/Instruments/electrophoresis/capillary/system/pages/default.aspx. Accessed December 7th 2010. • [7] {Sommer, S.; Kamps, R.; Schumm, S.; Kleinermanns K. F.GC/FT-IR/MS Spectroscopy of Native Polychlorinated Dibenzo-p-dioxins and Dibenzofurans Extracted from Municipal Fly-Ash. Analytical Chemistry, 69, 6, 1113-1118. 1997. • [8] Charles J. Wurrey, Donald F. Gurka, Billy J. Fairless, Robert D. Kleopfer, Applications of infrared spectroscopy to dioxin analyses of environmental samples, Chemosphere, Volume 18, Issues 1-6, Chlorinated Dioxins and Related Compounds, 1989, Pages 897-902

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