IAEA Reference Materials
Reference
Sheets
IAEA-V-8
TRACE ELEMENTS IN RYE FLOUR
Intended
Use
This
sample is intended to be used as a reference material for the measurement
of trace elements in vegetation samples. The material 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
A
batch of approximately 200 kg of rye flour (prepared in an industrial mill)
was homogenized at the Agency's Laboratories Seibersdorf. The batch was divided
into four 50 kg lots. Each lot was sub-divided into four equal parts and a
portion from each was re-combined to yield four new 50 kg batches. These batches
were homogenized in turn by mixing them in a rotating plastic drum for 24
hours. The cycle of sub-dividing, combining and mixing was repeated once more.
The material was then bottled into plastic containers each containing approximately
50 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:
January 1982
|
Unit Price:
50 €
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Unit Size:
50 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-V-8(.pdf) |
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| * | Number
of accepted laboratory results which were used to calculate the recommended
or information 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 conducted in 1981. The details concerning the criteria for qualification
as a recommended value can be found in the report (IAEA/RL/91) "Report on
the Intercomparison V-8 of the Determination of Trace Elements in Rye Flour"
[1]. This report is available free of charge upon request.
Homogeneity
The
within and between bottle homogeneity was evaluated by determining the content
of two marker elements (Zn and K) by instrumental neutron activation analysis.
A number of sub-samples (200 mg) was taken from a single bottle and an equal
number of single samples were taken from individual bottles selected at random.
A statistical analysis of the results using F and t-tests indicated that the
within and between bottle results did not differ significantly and the material
can therefore be considered homogeneous (at a sample intake mass at, or above,
200 mg).
Dry
weight determination
All
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 minimum sample size for analysis is 200 mg. Analysts are reminded
to take appropriate precautions in order to avoid contaminating the remaining
material in the bottle. No special precautions are required for the storage
of this material.
References:
| [1] |
Last updated 30 March 2004
