ASTM C1387-98
(Guide)Standard Guide for Determination of Technetium-99 in Soil
Standard Guide for Determination of Technetium-99 in Soil
SCOPE
1.1 This document is intended to serve as a reference for laboratories wishing to perform Tc-99 analyses in soil. Several options are given for selection of a tracer and for the method of extracting the Tc from the soil matrix. Separation of Tc from the sample matrix is performed using an extraction chromatography resin. Options are then given for the determination of the Tc-99 activity in the original sample. It is up to the user to determine which options are appropriate for use, and to generate acceptance data to support the chosen procedure.
1.2 Due to the various extraction methods available, various tracers used, variable detection methods used, and lack of certified reference materials for Tc-99 in soil, there is insufficient data to support a single method written as standard method.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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Designation: C 1387 – 98
Standard Guide for
the Determination of Technetium-99 in Soil
This standard is issued under the fixed designation C 1387; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope methods. The resulting solution is passed through an extraction
chromatography column. Technetium is known to be retained
1.1 This document is intended to serve as a reference for
by the extraction chromatography material while most other
laboratories wishing to perform Tc-99 analyses in soil. Several
elements pass through the column. The column is washed with
options are given for selection of a tracer and for the method of
dilute acid to remove any remaining interferents. The resin
extracting the Tc from the soil matrix. Separation of Tc from
may then be counted directly by adding it to a liquid scintil-
the sample matrix is performed using an extraction chroma-
lation cocktail and counting by liquid scintillation spectrom-
tography resin. Options are then given for the determination of
etry, or the Tc may be eluted from the resin for alternative
the Tc-99 activity in the original sample. It is up to the user to
counting or mass spectrometric techniques.
determine which options are appropriate for use, and to
generate acceptance data to support the chosen procedure.
4. Significance and Use
1.2 Due to the various extraction methods available, various
4.1 This guide offers several options for the determination
tracers used, variable detection methods used, and lack of
of Tc-99 in soil samples. Sample sizes of up to 200 g are
certified reference materials for Tc-99 in soil, there is insuffi-
possible, depending on the method chosen to extract Tc from
cient data to support a single method written as a standard
the soil matrix. It is up to the user to determine if it is
method.
appropriate for the intended use of the final data.
2. Referenced Documents
5. Interferences
2.1 ASTM Standards:
2 5.1 Any radionuclide not completely removed by the ex-
C 998 Sampling Surface Soil for Radionuclides
traction chromatography column that has a beta decay energy
C 999 Soil Sample Preparation for the Determination of
similar to or higher than Tc-99 will interfere when counting
Radionuclides
3 techniques are used for quantification of the Tc-99 activity.
D 1193 Standard Specification for Reagent Water
5.2 Any elements with a mass-to-charge ratio (m/z) of 99
E 11 Specification for Wire-cloth Sieves for Testing Pur-
4 (that is, naturally occurring isotope of Ru-99, or other artifi-
poses
cially produced elements of sufficient half-life with similar
3. Summary of Guide m/z) can interfere when using mass spectrometry for quantifi-
cation of the Tc-99 activity. Any element with the same m/z as
3.1 There are no stable isotopes of technetium.
the isotope used as an isotope dilution tracer or internal
Technetium-99 is produced by the fission of uranium and
standard will cause a bias in the yield correction. Corrections
plutonium, and has been released to the environment via
should be included in the mass spectrometry data reduction for
nuclear weapons testing and nuclear materials processing. In
known interferences.
an oxidizing environment, it exists as the very mobile pertech-
–
5.3 Additional interferences may be encountered, depend-
netate ion, TcO . Technetium-99 is a long-lived (half-life
ing on the tracer and measurement technique chosen. It is up to
213,000 years), weak beta (beta max of 293 keV) emitting
the user to determine and correct for any additional interfer-
radioisotope.
ences.
3.2 For the analysis of Tc-99 in soil, a tracer is added to the
sample matrix, or spiked duplicate samples are prepared, and
6. Apparatus
then the Tc is extracted from the soil matrix by one of several
6.1 Apparatus for the Extraction of Tc from Sample Matrix:
methods, including acid leaching or one of various fusion
6.1.1 See the individual extraction method descriptions to
compile a list of the equipment needed for the chosen extrac-
This guide is under the jurisdiction of ASTM Committee C-26 on Nuclear Fuel tion method.
Cycle and is the direct responsibility of Subcommittee D26.05 on Methods of Test.
6.2 Apparatus for the Purification of Tc from the Soil
Current edition approved February 10, 1998. Published April 1998.
Extract:
Annual Book of ASTM Standards, Vol 12.01.
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 1387
6.2.1 Extraction column—with a bed volume of several 7.4.1 See the individual extraction method descriptions to
milliliters for the extraction chromatography resin. compile a list of the reagents needed for the chosen extraction
6.2.2 Column extension funnels—that can be added to the method.
extraction column such that a few hundred milliliters of 7.5 Reagents for the Purification of Tc from the Sample
solution can be added to the column at one time. Matrix:
6.2.3 Column rack—to hold columns such that several 7.5.1 Extraction Chromatrography Resin— TEVA resin.
extractions can be performed simultaneously. 7.5.2 Prefilter Resin—a nonionic acrylic ester polymer resin
6.3 Apparatus for the Quantification of Tc-99: used to remove residual organic matter prior to the extraction
6.3.1 See the individual detection method descriptions to chromatography resin column.
compile a list of the equipment needed for the chosen detection 7.5.3 Hydrogen Peroxide—30 %.
method. 7.5.4 High Purity Nitric Acid—(HNO ) concentrated, spe-
cific gravity 1.42.
7. Reagents
7.5.5 1M Nitric Acid—Add 63 mL of high purity HNO to
7.1 Purity of Reagents—All chemicals should, at a mini- 900 mL of DI water, dilute to a final volume of 1 liter.
mum, be of reagent grade and should conform to the specifi- 7.5.6 4M Nitric Acid—Add 250 mL of high purity HNO to
cations of the Committee on Analytical Reagents of the 600 mL of DI water, dilute to a final volume of 1 liter.
American Chemical Society where such specifications are 7.6 Reagents for the Quantification of Tc-99:
available. High Purity reagents are suggested if mass spec- 7.6.1 See the individual detection method descriptions to
trometry is chosen as the detection method. Other grades of compile a list of the reagents needed for the chosen detection
method.
reagents may be used provided it is first determined that the
reagent is of sufficient purity to permit its use without lessening
8. Procedure
the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references
8.1 Collect samples in accordance with Specification C 998.
to water shall be understood to mean reagent water, as defined
8.2 Soil or Sediment Preparation:
by Type I of Specification D 1193.
8.2.1 Oven dry samples at a temperature not to exceed
7.3 Tracer:
105°C and homogenized in accordance with Specification
7.3.1 Isotope Dilution Yield Determination:
C 999.
7.3.1.1 Radiometric Yield Determination— Tc-95m or Tc-
8.2.2 Optional—Samples may be placed in a muffle oven to
99m have been used to monitor the chemical yield of the
decompose organic matter prior to the extraction of Tc. The
extraction and purification of Tc-99 prior to quantification.
muffling techniques reported vary significantly (2-4).Ifde-
[Example: Add 10 nCi of Tc-99m as a yield tracer when
sired, it is suggested that 5–10 g of the sample be weighed to
determining yield by gamma spectrometry.]
a high temperature crucible. Add the chosen yield monitor and
7.3.1.2 Mass Spectrometric Yield Determination—Tc-97
mix the sample. Wet the sample with concentrated ammonium
may be produced in a nuclear reactor in very limited quantities
hydroxide and mix, then dry under a heat lamp. It has been
to be used as an isotope dilution tracer for the mass spectro-
found that ammonium hydroxide will prevent the loss of the
metric determination of Tc-99 (1). [Example: Add 1 ng of
volatile Tc at higher temperatures. Place the sample in a muffle
Tc-97 as a yield tracer for mass spectrometry.]
oven for 24 hours at 500°C (4), or for 30–60 minutes at 600°C
7.3.2 Duplicate Sample Analysis to Monitor Chemical Yield:
followed by the addition of a few grams of ammonium nitrate
7.3.2.1 When no tracer is available, duplicate samples may
and 10 more minutes of heating if traces of carbon remain (2).
be analyzed, one spiked with a known amount of Tc-99 and one
8.3 Tc Extraction— These discussions are summaries from
unspiked. The chemical recovery of the spiked sample is then
available literature. The user must read the primary reference
used to correct the unspiked sample to obtain the original
for a complete discussion of the method prior to its use.
sample activity.
8.3.1 Acid Leaching— There are many reported acid leach-
7.4 Reagents for the Extraction of Tc-99 from Sample
ing techniques in the literature (2, 3, 5-9); however, only those
Matrix:
that are easily coupled to the extraction chromatography
purification are described in 8.3.1.1-8.3.1.4.
8.3.1.1 Weigh out up to 10 grams of soil to a 250 mL glass
Prepacked columns from EIChroM Industries (Darien, IL) or BioRad (Rich-
beaker along with the desired yield monitor. Cover and heat the
mond, CA) poly prep columns have been found satisfactory for this purpose.
6 sample in the presence of 1M nitric acid. After cooling, remove
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, D. C. For suggestions on the testing of reagents not residual solid matter from the sample by centrifugation. Add
listed by the American Chemical Society, Washington, D. C. For suggestions on the
hydrogen peroxide and sodium vanadate to each sample to
testing of reagents not listed by the American Chemical Society, see Analar
destroy residual organic matter. Finally, reduce the acidity of
Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U. K., and the
the sample to less than 0.5M using ammonium hydroxide
United States Pharmacopeia and National Formulary, U.S. Pharmaceutical Con-
vention (USPC), Rockville, MD.
Tc-95m may be obtained from Analytics, Inc., Atlanta, GA, or other suitable
supplier.
8 10
Tc-99m may be obtained from a local medical pharmacy supplier or other TEVA resin from EIChroM Industries has been found satisfactory for the
suitable supplier. purposes listed. No other commercial sources of equivalent material are known.
9 11
The boldface numbers in parentheses refer to the list of references at the end of Prefilter columns are available from EIChroM Industries or Amberchrom
this standard. GC-71CD resin has been found satisfactory for this purpose.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 1387
(dilute with water to a final sample volume of approximately power for 30–60 minutes. Let the vessels cool completely
500 mL) (5). before venting and opening. Pour the solution to a beaker.
Rinse the vessel with water and add to the sample beaker.
8.3.1.2 Add the desired yield monitor to 5–10 g of sample,
Dilute to a final volume of 200–250 mL such that the final acid
which is then ashed using step 8.2.2. Leach the sample twice
solution is less than 0.5M (12).
with hot 8M nitric acid and hydrogen peroxide, combining the
8.3.3.2 Weigh out up to 0.5 gram of sample to a tared Teflon
leachates. Adjust the pH to 7 with sodium hydroxide and filter
liner. Add the desired yield monitor to each sample. Add 10 mL
the solution through a glass fiber filter. Dilute the water to
of concentrated nitric acid to each sample. Allow the samples
approximately 500 mL (6).
to predigest in the open vessel for at least 15 minutes. Place the
8.3.1.3 Weigh out up to 200 grams of sample. Add the
Teflon liners into the microwave digestion vessels and place in
desired yield monitor. Ash using step 8.2.2. Transfer the sample
the microwave oven in accordance with the manufacturers
to a decomposition vessel. Add 6M nitric acid. Decompose the
specifications. Heat the samples in stages up to a maximum of
sample at 100–120°C for one hour. Filter the sample through a
200°C and 600 psi. Allow the samples to cool to less than 30
glass fiber filter then dilute with water until the acid concen-
psi and 80°C. The vessels are manually vented and the sample
tration is less than 0.5M nitric acid (at least 500 mL) (7).
solution transferred to a labeled container with water. Any
8.3.1.4 Weigh out one gram of the dried, unashed sample to
undigested residue is removed by centrifugation. Dilute the
a 250 mL conical flask. Add the desired yield monitor. Add
final solution with water such that the final acid concentration
concentrated nitric acid and fit into a reflux condenser. Reflux
is less than 0.5M in nitric acid, about 350 mL (13).
the sample until the brown fumes cease and all the organic
8.4 Tc Purification by Extraction Chromatography Separa-
matter is dissolved. Cool the flask and pour the solution into
tion (5):
water. Neutralize the solution with sodium hydroxide, filter out
8.4.1 Place a column in the column rack for each sample to
any undissolved residue, and dilute to a final volume of
be analyzed. Prefilled extraction chromatography columns are
approximately 250–500 mL (8).
available or add about 2 mL of extraction resin to a standard
8.3.2 Soil Fusion—The following two methods have been
column geometry. For samples containing residual organic
used for Tc-99.
matter, it is chromatography column.
8.3.2.1 Weigh out four grams of sample. Add the desired 8.4.2 Condition each extraction column by adding 5 mL of
0.1M nitric acid to each column, and allow to drain.
yield monitor and ash using step 8.2.2. When cool, transfer the
sample to a Ni crucible. Add 20 gram of the flux mixture 8.4.3 Add the column extension funnels to each column and
then pour the solution obtained above in the Tc extraction
(Na CO ,K CO and NaNO in a 3.92:5.08:1.00 weight ratio;
2 3 2 3 3
the flux-to-sample ratio should be 5:1). Start the fusion by section through the columns. Solution volumes of 100 to over
500 mL are generated by the Tc extraction procedures above.
heating the crucible with the sample over a burner at high heat.
Technetium will be retained by the extraction chromatography
When no further reaction is visible, co
...
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