title: Using tea as an artificial urine in a Canadian performance testing program for fission/activation products.
abstract: In recent years, the National Calibration Reference Centre for Bioassay and In Vivo Monitoring (NCRC) at the Radiation Protection Bureau (RPB), Health Canada, has been conducting investigations with black tea to develop a matrix that can be used to replace urine in each of the following performance testing programs (PTP): (1) tritium, (2) carbon-14, (3) the DUAL (i.e., 3H/14C), and (4) fission/activation products (F/AP). A 1% tea solution with thimerosal, which had worked successfully for tritium, carbon-14, and the DUAL, was selected and tested for the F/AP PTP because of its similarity to urine in color and UV-VIS spectra. However, application of this tea to samples of the F/AP program containing 133Ba, 137Cs, 57Co, and 60Co produced precipitates, which was an unexpected result. Further experiments showed that replacement of thimerosal with an alcohol at about 5% eliminated the precipitation problem. The alcohol can be ethanol, methanol, or isopropanol. In the experiments, the 1% tea, preserved with alcohol, remained clear and stable for at least 100 d. The duration of each PTP for the NCRC is limited to 90 d. Application of the CNSC S-106 regulatory standard to the tea produced acceptable accuracy and precision results. It was concluded that a suitable tea matrix for the F/AP program had been found.
authors.affiliation: *National Calibration Reference Centre, Radiation Protection Bureau, Health Canada, 775 Brookfield Road, P.L # 6302D, Ottawa, ON, Canada K1A 1C1.
authors.forename: Joseph N
authors.initials: JN
authors.lastname: Daka
authors.forename: Gerry
authors.initials: G
authors.lastname: Moodie
authors.forename: Anthony
authors.initials: A
authors.lastname: DiNardo
authors.forename: Gary H
authors.initials: GH
authors.lastname: Kramer
mesh_terms: D001681:Biological Assay / Q000592:standards*; D002138:Calibration; D002250:Carbon Radioisotopes; D006801:Humans; D009680:Nuclear Fission; D011834:Radiation Monitoring / Q000592:standards*; D011835:Radiation Protection / Q000592:standards*; D018788:Radioactive Hazard Release; D013662:Tea / Q000737:chemistry*; D014316:Tritium / Q000032:analysis*; D014556:Urine / Q000737:chemistry*
chemical_list: D002250:Carbon Radioisotopes; D013662:Tea; D014316:Tritium