IAEA Reference Materials
Reference
Sheets
IAEA-SL-2
RADIONUCLIDES IN LAKE SEDIMENT
Intended
Use
This
sample is intended to be used as a reference material for the measurement
of 40K and 137Cs in lake sediment samples. It can also be used as a quality
control material for the assessment of a laboratory's analytical work, for
the validation of analytical methods and for quality assurance within a laboratory.
Origin
and preparation of the material
The
lake sediment was collected from the Neusiedlersee, located some 80 km south-east
of Vienna, Austria. The material was collected directly from the top layer
of the sediment using a mud pump and then coarse particle were removed in
the field by passing the sediment through a 1 cm sieve.
After removal of the superficial water, the sediment material
still retained approximately 46% water by weight. The material was allowed
to air dry for one month before being dried in an oven at 400 °C for 24
hours. After drying, the material was milled to pass a 500 µm sieve.
This fraction was then passed through a 71 µm sieve. The portion of
the material with a size fraction between 72 and 500 µm was designated
SL-2 and used for an intercomparison study of radionuclides. The material
was thoroughly mixed in a rotating plastic drum for 10 hours and then bottled
into plastic containers each containing approximately 250 g. Finally, the
samples were irradiated to a dose of 2.5 x 104 Gy using a 60Co
source to ensure long-term stability of the material by inhibiting microbial
action.
Date of Release:
May 1987
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Unit Price:
90 €
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Unit Size:
250 g
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| Producer:
Chemistry Unit Agency's Laboratories, Seibersdorf A-2444 Seibersdorf, Austria |
Supplier:
Analytical Quality Control Services Agency's Laboratories, Seibersdorf A-2444 Seibersdorf, Austria |
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Reference Sheet:  IAEA-SL-2(.pdf) |
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Reference
Date for decay correction: 31st January 1986 |
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Number of accepted laboratory results which were used to calculate the
recommended values and their respective confidence intervals about the
mean value. |
| (R/I) | Classification
assigned to the property value for Analyte (Recommended/Information) |
The values listed
above were established on the basis of statistically valid results submitted
by laboratories which had participated in an international intercomparison
exercise organized during 1986-1987. The details concerning the criteria for
qualification as a recommended value can be found in the report (IAEA/RL/142)
"Report on the Intercomparison Run IAEA-SL-2: Radionuclides in Lake Sediment"
[1]. This report is available free of charge upon request.
Homogeneity
The
homogeneity of the material was assessed by measuring the 40K and
137Cs activity in ten bottles, chosen at random, using gamma spectrometry.
Taking into consideration the activity concentrations measured for 137Cs
and 40K, the material could be considered homogeneous for sample
sizes of 250 g.
Dry
weight determination
All recommended
values are expressed on a dry weight basis. Therefore the dry weight must
be determined at the time of analysis, using separate sub-samples of at least
500 mg dried to constant weight in a drying oven set to 105 °C. Subsequent
weighings should differ by less than 5 mg.
Instructions
for use
The
recommended sample size for analysis is 250 g. Analysts are reminded to take
appropriate precautions in order to avoid contamination of the material during
handling. No special precautions are required for the storage of this material.
References:
| [1] |
Last updated 30 March 2004
