Common analytical errors in the radiodating of recent sediments

Journal Article · · Environmental Geology and Water Sciences; (USA)

DOI:https://doi.org/10.1007/BF01705132· OSTI ID:5948864

Joshi, S R ^[1]

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1. National Water Research Institute, Ontario (Canada)

Four possible sources of analytical error in the measurement of unsupported {sup 210}Pb and/or nuclear fallout radionuclide (such as {sup 137}Cs) profiles in sediment core are (1) Freezing the entire sediment core prior to precise sectioning; (2) Sectioning the sediment core at room temperature or lower; (3) Determining {sup 210}Pb via its 5.01-day half-life beta emitting daughter {sup 210}Bi; (4) Determining {sup 210}Pb via the 138-day alpha-emitting granddaughter {sup 210}Pb. Simple procedural modifications can substantially improve the quality of analytical data that are subsequently used to develop intricate mathematical models to aid the interpretation of observed radionuclide profiles. These modifications include (1) Always store subsamples for sufficiently long periods of time to ensure equilibrium between {sup 210}Po and unsupported {sup 210}Pb; (2) Always use {sup 208}Po as yield monitor and assay autoplated sources on an alpha-particle counter since the alpha particle energies of {sup 208}Po and {sup 210}Po are separable only on a spectrometer using a detector; (3) Never use any glassware for radiochemical work involved polonium since several polonium compounds are known to absorb onto glass surfaces. Quartz is perhaps the best choice though Teflon or similar materials are also suitable for most situations. Avoid heating above 120 C during HCl leaching and above 90 C during plating since PoCl{sub 4} is highly volatile.

• OSTI ID: 5948864
• Journal Information: Environmental Geology and Water Sciences; (USA), Journal Name: Environmental Geology and Water Sciences; (USA) Vol. 14:3; ISSN 0177-5146; ISSN EGWSE
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540330* -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- (1990-)
AGE ESTIMATION
ALKALI METAL ISOTOPES
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BISMUTH 210
BISMUTH ISOTOPES
CESIUM 137
CESIUM ISOTOPES
DATA COVARIANCES
DAYS LIVING RADIOISOTOPES
ECOLOGICAL CONCENTRATION
ELECTRON CAPTURE RADIOISOTOPES
EVEN-EVEN NUCLEI
HALF-LIFE
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE DATING
ISOTOPES
LEAD 210
LEAD ISOTOPES
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MONITORING
NANOSEC LIVING RADIOISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
POLONIUM 208
POLONIUM 210
POLONIUM ISOTOPES
RADIATION DETECTORS
RADIATION MONITORING
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
SEDIMENTS
YEARS LIVING RADIOISOTOPES