Detection of the Rate Bisphenol-A Leaches into Water from PVC film Aimee Kwong CHEM4101, Fall 2008What is Bisphenol-A? BPA, short for Bisphenol-A, is contained in many polyvinyl carbonate plastics (#7) as a hardener1 i.e. Water bottles, baby bottles, food containers PROBLEM? • BPA is found to mimic the hormone estrogen leading towards many medical illnesses • Recent studies have linked low doses of BPA to obesity, diabetes, thyroid disease, breast cancer, prostate cancer and other illnesses.1Experimental Problem What procedure would allow sampling and detection of the rate at which Bisphenol-A leaches into water. Purpose To have more background towards human interaction with everyday plastics used in the home Hypothesis The rate of BPA leaching into water (pH 4, 7, 10) through PVC film in elevated temperature can be determined through appropriate testing methods.Toxicity2 Dose (µg/kg body weight/day) Human Effects Reference 0.0001 alterations in cell signalling pathways on the cell surface that control calcium eflux in cells Wozniak 2005 0.025 persistent changes to breast tissue, predisposes cells to hormones and carcinogens Muñoz-de-Toro 2005 10 insulin resistance develops in 2 days, chronic hyperinsulinemia at day 4 Alonso-Magdalena 2006 50 U.S. human exposure limit (EPA) EPA 1998Gas Chromatography/Mass Spectrometry Low limit of detection: 0.01μg/L BPA is volatile with a boiling point 220oC/ 4 mmHg m/z is within range of the mass analyzer A retention time around 16.45 min m/z value of 228 Possible interferences: Polybrominate, polychlorinate, Organotin, Organophosphe, Adipates Method of ChoiceFISONS GC 8000/MD8001 Parameters of Instrument : $14,000 Gas Chromatogram • Carrier Gas: He • Quadrapole mass filter1 • Injector Temperature: 275°C • Detector temperature 200°C • HP 7673 Autosampler • Separation with a DB-5MS fused silica column • Split mode: 1:20 • Column Temperature • 150oC (2 min) to 5oC min-1 • to 270oC (5 min) Mass Spectrometer • Interphase temperature: 500oC • Electron Impact: 70eV • Full Scan: m/z 20-500 • Resolution: 228 • Accuracy 0.13% • Computer Program: MassLab version 1.3 Column Parameters • (30m x 0.25 mm ID; film thickness 1.4 µm) • DB-5MS Temperature Range: -60 – 325oCAlternative Methods Infrared Spectroscopy3 The different attributes or stretching of BPA can be detected Will show other interferents and their structure composition Relatively fast and easy technique Does not have the selectivity needed Fluorescence Spectroscopy4 Limit of Detection is 0.6 ng/mL Sensitive to contaminants or interferents and their propertiesStandard:1 g PVC film cut and put into 300 mL acetonitrile for 24 hours at 60°C Experimental: 1 g PVC film cut and put into 300 mL Water (pH 4, 7, 10) at 60°C After 24 hour treatment every 2 hours an aliquot of water sample was filtered through glass wool and 30 g of sodium chloride. Leachate acidified with HCl (pH<2), extracted with 50 mL dichloromethane, and concentrated on a rotary evaporator to 2 mL. Further concentrated to 1 mL under nitrogen stream and 1 μL injected to GC/MS Method Overview1, 7 Fisons GC8000/MD800 www.gees.bham.ac.ukAnalyze the Results Measure the areas of the peaks for each consecutive timed sample Find the rate at which BPA leaches into liquid when PVC film comes in contact with 60oC acetonitrile Compare acetonitrile values with the rates leaching into three different water samples (pH 4, 7, 10) BPA in PVC film7 • 347 μg/g • Percentage of BPA leached from sample of water (pH 7): • 1.8 x 10-3% • Used 1 g sample in 300 mL liquid to achieve 0.02 μg/L at injectionSample Spectrum1 Gas Chromatography Mass Spectroscopy The peak at 213 shows the fragmentation of CH3 from the original structureConclusions BPA will leach into liquid when the PVC film comes in contact with liquid under elevated temperatures After extraction pH<6.5 is shown to have more effective extraction rates of BPA8 If rate is determined to be lower than toxic levels listed, levels of BPA cannot be harmful to humans The rate at which BPA leaches into the liquid can be further investigated by determining the change of rates under different temperature conditionReferences 1. Cervantes, J. L., Food Additives & Contaminants: Part A, 2008, 20, 596-606. 2. Vandenberg, L. N., Reproductive Toxicology, 2007, 24, 139-177. 3. Zafra, A., Water Research, 2003, 37, 735-742. 4. Bae, B. Water Science and Technology, 2002, 46, 381-387. 5. Scott, R. P. W., Liquid Chromatography Detectors: Second, Completely Revised Edition., Elsevier, 1986. 6. Smith, B., Infrared Spectral Interpretation: A Systematic Approach., CRC Press, 1999. 7. Yamamoto, T., Chemosphere, 1999, 38, 2569-2576. 8. Nollet, L. M., Handbook of Water Analysis, CRC Press,
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