title: An alternative method of OBT measurement for the limited quantity of environmental samples using a combustion bomb.
abstract: The measurement of organically bound tritium (OBT) in environmental samples is much more difficult than the measurement of tritiated water (HTO). This study describes an alternative method for OBT determination in plant materials in which tritium-free polyethylene beads are added to the plant sample prior to combustion in a combustion bomb. It is not always possible to collect large enough amounts of some plants (e.g. algae, plankton, grass) within a specific area or specific period. Excellent water recovery is achieved when dry plant materials are combusted with polyethylene beads. When Ultima Gold AB is used as the scintillation cocktail, it is possible to measure the combustion water directly without distillation. Correction factors were derived for the plants used in the study to account for the dilution of the combustion water due to addition of the polyethylene beads. The alternative method has a number of advantages, including an increased yield of combustion water for liquid scintillation counting, less color quenching, reduced sample size and decreased analysis time. Finally, accuracy tests comparing results of the conventional method with those of the alternative method were carried out using environmental samples.
authors.affiliation: Environmental Technologies Branch, Chalk River Laboratories, AECLChalk River, Ontario, Canada, K0J 1J0. Electronic address: kimsb@aecl.ca.
authors.forename: Sang Bog
authors.initials: SB
authors.lastname: Kim
authors.forename: Marilyne
authors.initials: M
authors.lastname: Stuart
mesh_terms: D005507:Food Contamination, Radioactive / Q000032:analysis*; D006358:Hot Temperature; D009930:Organic Chemicals / Q000032:analysis; D010945:Plants, Edible / Q000737:chemistry*; D020959:Polyethylene; D012588:Scintillation Counting; D014316:Tritium / Q000032:analysis*; D014867:Water
chemical_list: D009930:Organic Chemicals; D014867:Water; D014316:Tritium; D020959:Polyethylene
keywords: Combustion bomb; Organically bound tritium; Polyethylene beads