Technetium-99 cycling in maple trees: Characterization of changes in chemical form

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · Health Physics; (USA)

DOI:https://doi.org/10.1097/00004032-198908000-00008· OSTI ID:5600347

Garten, Jr, C T; Lomax, R D ^[1]

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1. Oak Ridge National Lab., TN (USA)

Prior field studies near an old radioactive waste disposal site at Oak Ridge, TN, indicated that following root uptake, metabolism by deciduous trees rendered 99Tc less biogeochemically mobile than expected, based on chemistry of the pertechnetate (TcO-4) anion. Subsequently, the form of technetium (Tc) in maple tree (Acer sp.) sap, leaves, wood and forest leaf litter was characterized using one or more of the following methods: dialysis, physical fractionation, chemical extraction, gel permeation chromatography, enzymatic extraction, or thin layer chromatography (TLC) on silica gel. Chromatography (Sephadex G-25) of TcO-4 incubated in vitro with tree sap showed it to behave similar to TcO-4 anion. When labeled wood and leaf tissues were processed using a tissue homogenizer, 15% and 40%, respectively, of the Tc was solubilized into phosphate buffer. Most (65% to 80%) of the solubilized Tc passing a 0.45-micron filter also passed through an ultrafiltration membrane with a nominal molecular weight cutoff of 10,000 atomic mass units (amu). A majority (72% to 80%) of the Tc in wood could be chemically removed by successive extractions with ethanol, water and weak mineral acid. These same extractants removed only 23% to 31% of the Tc from maple leaves or forest floor leaf litter. Most of the Tc in leaves and leaf litter was removed only by strongly alkaline reagents typically used to release structural polysaccharides (hemicelluloses) from plant tissues. Chromatography (Sephadex G-25) of the ethanol-water extract from wood and the alkaline extract from leaves demonstrated that Tc in these extracts was not principally TcO-4 but was complexed with molecules greater than 1000 amu. Incubations of leaf and wood homogenates with protease approximately doubled the amount of Tc released from contaminated tissues.

• OSTI ID: 5600347
• Journal Information: Health Physics; (USA), Vol. 57:2; ISSN 0017-9078
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
MAPLES
RADIONUCLIDE KINETICS
TECHNETIUM 99
METABOLISM
CHROMATOGRAPHY
FOREST LITTER
PERTECHNETATES
RADIOACTIVE WASTES
REAGENTS
ROOT ABSORPTION
SOLVENT EXTRACTION
WOOD
ABSORPTION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
EXTRACTION
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MATERIALS
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PLANTS
RADIOACTIVE MATERIALS
RADIOISOTOPES
REFRACTORY METAL COMPOUNDS
SEPARATION PROCESSES
TECHNETIUM COMPOUNDS
TECHNETIUM ISOTOPES
TRANSITION ELEMENT COMPOUNDS
TREES
UPTAKE
WASTES
YEARS LIVING RADIOISOTOPES
560162* - Radionuclide Effects
Kinetics
& Toxicology- Animals
Plants
Microorganisms
& Cells