Determination of {sup 230}Th, {sup 234}U, {sup 239}Pu, and {sup 240}Pu in soils by ICP-MS using flow-injection preconcentration

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:409718

Hollenbach, M; Grohs, J; Mamich, S ^[1]; Kroft, M ^[2]

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1. RUST Geotech Inc., Grand Junction, CO (United States)
2. EiChrom Industries, Darien, IL (United States)

The US Department of Energy needs improved analytical methods for alpha-emitting radionuclides to support environmental restoration and waste management projects. Inductively coupled plasma-mass spectrometry (ICP-MS) has been used successfully to measure radionuclides with relatively long half-lives; however, ICP-MS used with conventional sample introduction techniques lacks the sensitivity or selectivity to measure shorter-lived radionuclides at levels important for environmental monitoring. New methods were developed for measuring {sup 230}Th, {sup 234}U, {sup 239}Pu, and {sup 240}Pu in soils. Samples are dried, ground, and dissolved by fusion. A flow injection (FI) analysis system is used to separate and concentrate the analytes by solid-phase extraction. The FI eluent is pumped directly into the nebulizer of the ICP-MS. The use of FI resulted in greater sensitivity and freedom from interferences when compared with direct aspiration. Detection limits are improved by approximately a factor of 20. The detection limits are approximately 3 Bq/kg (4 ng/kg) for {sup 230}Th, 0.6 Bq/kg (3 ng/kg) for {sup 234}U, 0.4 Bq/kg (0.2 ng/kg) for {sup 239}Pu, and 2 Bq/kg (0.3 ng/kg) for {sup 240}Pu. The FI-ICP-MS methods are faster, less labor intensive, and generate less laboratory waste than traditional radiochemical methods. The FI-ICP-MS gives individual results for {sup 239}Pu and {sup 240}Pu which cannot be resolved by the usual radiochemical method. The accuracy of the methods was verified by analyzing reference soils.

• OSTI ID: 409718
• Report Number(s): CONF-9410207--; ISBN 0-8031-2034-6
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
ACCURACY
CHEMICAL ANALYSIS
CONCENTRATION RATIO
DISSOLUTION
EXPERIMENTAL DATA
EXTRACTION
HYDROFLUORIC ACID
ICP MASS SPECTROSCOPY
INTERFERING ELEMENTS
NITRIC ACID
PLUTONIUM 239
PLUTONIUM 240
QUALITY CONTROL
QUANTITATIVE CHEMICAL ANALYSIS
SAMPLE PREPARATION
SOILS
STANDARDS
THORIUM 230
URANIUM 234