I-131 in Japanese Milk Supply Joe Zibley CHEM 4101Hypothesis Problem My hypothesis is that the highest levels of I-131 in milk will be found in the milk from the farms closest to the Fukushima Nuclear Power Plant. •I-131 released during Fukushima disaster and made its way into milk supply •Causes thyroid cancer especially in very young and the elderly •Public perception of unsafe food and drink from JapanBackground • I-131 is radioactive isotope ▫ Βeta and Gamma Emission ▫ Exact Mass of 130.906 1246 amu ▫ Half-Life of 8.02 days ▫ Thyroid Cancer • Japan Milk Activity Maximum ▫ 300 Bq/KgTechniques Considered Technique Advantages Disadvantages ICP-MS •Literature References •Differentiate Isotopes •Low LOD: 0.1-10 ppb •Expensive •Sample Prep HPLC-MS •Differentiate Isotopes •Sample Separation •Expensive •Sample Prep •Time IntensiveGermanium Detector • Semiconductor diode with P-I-N structure • Sensitive to X-ray and gamma rays • Reverse Bias • Photons create charge carriers in intrinsic region • Charge is proportional to energy of photons • No Sample PreparationDetection DiagramTypes of Detectors • Hand-Held • Industrial Size • Portal Monitors Canberra Ge Detectors http://www.canberra.com/ Ortec Ge Portal Monitor http://www.ortec-online.com/Instrument • Canberra Extra Range Coaxial Ge Detector ▫ 3 KeV-2000 KeV ▫ High Efficiency ▫ FWHM Resolution 0.9-2KeV ▫ Moderate Cost • Additional Shielding • Need to account for geometric efficiencyExpected Results • Counts vs. Energy(KeV) • Count-electronic pulses initiated by radiation striking detector • Counting Rate (R) is proportional to activity(A) ▫ R=cA • Need calibration curve to identify instrument efficiency(c) Canberra Gamma and X-Ray Detection Brochure http://www.canberra.com/Proposal • Germanium detectors at milk processing plants • Sample incoming milk ▫ Prevents exposure to public ▫ Prevents contamination of processing equipment ▫ Trace milk back to sourceConclusion • Can monitor I-131 activity in milk • Fast, cost-effective, and easy analysis • Extend to monitor many radioactive isotopes http://www.thefatlossauthority.comReferences • Canberra. Germanium Detectors. http://www.canberra.com/products/465.asp (accessed Dec. 6, 2011). • National Institute of Standards and Technology. Atomic Weights and Isotopic Compositions for All Elements. http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=&all=all&ascii=html&isotype=all (accessed Oct. 27, 2011). • Ortec. Introduction to Semiconductor Photon Detectors. http://www.ortec-online.com/Solutions/RadiationDetectors/index.aspx (accessed Dec. 6, 2011). • Shelor, C.P.; Dasgupta, P.K.; Review of analytical methods for the quantification of iodine in complex matrices. Analytica Chimica Acta. 2011, 702,
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