ASTM D3972-09(2015)
(Test Method)Standard Test Method for Isotopic Uranium in Water by Radiochemistry (Withdrawn 2024)
Standard Test Method for Isotopic Uranium in Water by Radiochemistry (Withdrawn 2024)
SIGNIFICANCE AND USE
5.1 This test method was developed to measure the radioactivity of uranium isotopes in environmental waters or waters released to the environment, and to determine whether the uranium-isotope concentrations are below the maximum amounts allowable by any regulatory statute.
SCOPE
1.1 This test method covers the determination of alpha-particle-emitting isotopes of uranium in water by means of chemical separations and alpha pulse-height analysis (also known as alpha-particle spectrometry). Uranium is chemically separated from a water sample by coprecipitation with ferrous hydroxide, anion exchange, and electrodeposition. The test method applies to soluble uranium as well as to any uranium that might be present in suspended matter in the water sample. This test method is applicable for uranium processing effluents as well as substitute ocean water. When suspended matter is present, an acid dissolution step is added to assure that all of the uranium dissolves. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific warning statements are given in Section 9.
WITHDRAWN RATIONALE
This test method covers the determination of alpha-particle-emitting isotopes of uranium in water by means of chemical separations and alpha pulse-height analysis (also known as alpha-particle spectrometry). Uranium is chemically separated from a water sample by coprecipitation with ferrous hydroxide, anion exchange, and electrodeposition. The test method applies to soluble uranium as well as to any uranium that might be present in suspended matter in the water sample. This test method is applicable for uranium processing effluents as well as substitute ocean water. When suspended matter is present, an acid dissolution step is added to assure that all of the uranium dissolves. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
Formerly under the jurisdiction of Committee D19 on Water, this test method was withdrawn in February 2024 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3972 − 09 (Reapproved 2015)
Standard Test Method for
Isotopic Uranium in Water by Radiochemistry
This standard is issued under the fixed designation D3972; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope in Closed Conduits (Withdrawn 2003)
D1193Specification for Reagent Water
1.1 This test method covers the determination of alpha-
D2777Practice for Determination of Precision and Bias of
particle-emitting isotopes of uranium in water by means of
Applicable Test Methods of Committee D19 on Water
chemical separations and alpha pulse-height analysis (also
D3084Practice for Alpha-Particle Spectrometry of Water
known as alpha-particle spectrometry). Uranium is chemically
D3370Practices for Sampling Water from Closed Conduits
separated from a water sample by coprecipitation with ferrous
D3648Practices for the Measurement of Radioactivity
hydroxide, anion exchange, and electrodeposition. The test
D5847Practice for Writing Quality Control Specifications
method applies to soluble uranium as well as to any uranium
for Standard Test Methods for Water Analysis
that might be present in suspended matter in the water sample.
D7282Practice for Set-up, Calibration, and Quality Control
This test method is applicable for uranium processing effluents
of Instruments Used for Radioactivity Measurements
as well as substitute ocean water. When suspended matter is
present, an acid dissolution step is added to assure that all of
3. Terminology
the uranium dissolves. It is the user’s responsibility to ensure
3.1 Definitions:
the validity of this test method for waters of untested matrices.
3.1.1 For definitions of terms used in this test method, refer
1.2 The values stated in SI units are to be regarded as
to Terminologies C859 and D1129. For terms not included in
4,5
standard. No other units of measurement are included in this
these reference may be made to other published glossaries.
standard.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4.1 Thewatersampletobeanalyzedisacidifiedand Uis
added to serve as an isotopic tracer before any additional
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- operations are performed. If the sample is a seawater sample,
orifitcontainscarbonateorbicarbonateions,thesamplemust
bility of regulatory limitations prior to use. Specific warning
statements are given in Section 9. be boiled under acidic conditions to convert these ions to
carbon dioxide gas which is then expelled from the solution.
Carbonate ions must not be present during the precipitation
2. Referenced Documents
step because they complex the uranium and prevent its
2.1 ASTM Standards:
coprecipitation.Theuraniumiscoprecipitatedfromthesample
C859Terminology Relating to Nuclear Materials
with ferrous hydroxide. This precipitate is dissolved in con-
C1163PracticeforMountingActinidesforAlphaSpectrom-
centrated hydrochloric acid, or is subjected to an acid dissolu-
etry Using Neodymium Fluoride
tion with concentrated nitric and hydrofluoric acids if the
D1066Practice for Sampling Steam
hydrochloric acid fails to dissolve the precipitate.
D1129Terminology Relating to Water
4.2 The uranium is separated from other radionuclides by
D1192Guide for Equipment for Sampling Water and Steam
adsorption on anion-exchange resin from 8 M hydrochloric
acid, followed by elution with 0.1 M hydrochloric acid. The
uraniumiselectrodepositedontoastainlesssteel disk.Isotopic
This test method is under the jurisdiction ofASTM Committee D19 on Water
uranium radioactivities are measured by alpha pulse-height
andisthedirectresponsibilityofSubcommitteeD19.04onMethodsofRadiochemi-
cal Analysis.
Current edition approved Jan. 1, 2015. Published January 2015. Originally
approved in 1980. Last previous edition approved in 2009 as D3972–09. DOI: The last approved version of this historical standard is referenced on
10.1520/D3972-09R15. www.astm.org.
2 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Parker, S. P., ed., Dictionary of Chemical Terms, McGraw-Hill Book Co., New
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM York, NY, 1985.
Standards volume information, refer to the standard’s Document Summary page on IUPAC, “Glossary of Terms Used in NuclearAnalytical Chemistry,” Pure and
the ASTM website. Applied Chemistry, Vol 54, 1982, pp. 1533–1554.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3972 − 09 (2015)
TABLE 1 Relevant Properties of Uranium Isotopes of Interest in
(25.4%),5.03(23%),4.951(22.5%),5.059(11%),and4.734
A
Environmental Waters 231
(8.4%). Thus, from Table 1, it is seen that Pa can interfere
233 234
Half Life Principal Alpha Energies in MeV
with the determination of Uor U. However, when the
Isotope
Years (Abundance) 231
4.951 to 5.059 MeV Pa peaks can be resolved from the
U 68.9 5.320(68.6)
uranium peaks, a correction can be made. Neptunium-237 has
5.262(31.4)
alpha emission energies ranging from 4.639 to 4.873 MeV,
233 5
U 1.592×10 4.824(83.3) with 72% found between 4.771 and 4.788 MeV. Conventional
4.782(14.1)
analytical equipment would not be able to resolve these peaks
234 5 from normal U emissions. If Np-237 is suspected to be
U 2.455×10 4.774(72.5)
4.722(27.5)
present in the sample, a separate Np analysis would be
required to make the appropriate correction to the U result.
235 8
U 7.038×10 4.596(5.6)
4.307 (57)
6.2 When measuring very low concentrations of uranium
4.366 (17)
isotopes in environmental samples, detector backgrounds and
4.214(6.4)
laboratory blanks must be well known. Blank determinations
236 7
U 2.342×10 4.493 (74)
are made to ascertain that any contamination from reagents,
4.445 (26)
glassware and other laboratory apparatus is small compared to
238 9
U 4.468×10 4.198 (77)
the activity in the sample that is being analyzed. A blank
4.151 (23)
determination should be made in exactly the same way as the
A
Table of Isotopes, Eighth Edition, Vol. 11, Richard B. Firestone, Lawrence
sample determination.
Berkeley National Laboratory, University of California, 1996.
7. Apparatus
7.1 Centrifuge, 250-mL centrifuge bottle or tube capacity.
analysiswithasiliconsurface-barrierorion-implanteddetector
7.2 Ion Exchange Column, glass or plastic, approximately
and a multichannel analyzer.
232 13-mm inside diameter and 150 mm long with a glass-wool
4.3 When U is used as the tracer, the other isotopes of
plug or plastic frit and a 100- to 150-mL reservoir.
uranium listed in Table 1 can be detected in the alpha-particle
7.3 Electrodeposition Apparatus, consisting ofa0to 12-V,
spectrum of an unknown sample. From the alpha energies
given in the table, it can be seen that the alpha energy of U 0 to 2-A power supply (preferably constant current) and an
electrodepositioncell.Thecathodeisanapproximately20-mm
is more than 0.40 MeV higher than the energy of any other
uranium isotope. Thus, there should be little interference from diameter stainless steel disk polished to a mirror finish. The
232 233
anode is approximately 1-mm diameter platinum wire with an
tailing of the U into the lower energy alpha peaks. U
and U usually cannot be resolved because their principal approximately 8-mm diameter loop at the end of the wire
235 236
alpha energies differ by only 0.04 MeV. U and U peaks parallel to the cathode disk. Cooling of the electrolyte during
can be resolved only with difficulty. The alpha peaks from electrodeposition to at least 50°C is recommended. See refer-
other combinations of uranium isotopes can be resolved unless ences in Section 8 of Practice D3084 for more details.
the quality of the finally prepared sample is poor.
7.4 Alpha Pulse-Height Analysis System, consisting of a
silicon surface-barrier or ion-implanted detector, supporting
5. Significance and Use
electronics, and pulse-height analyzer. A system capable of
5.1 This test method was developed to measure the radio-
givingaresolutionof30keVFWHMorbetter,whenmeasured
activity of uranium isotopes in environmental waters or waters
with a high-quality source, is recommended. The counting
released to the environment, and to determine whether the
efficiency of the system should be greater than 15%, and the
uranium-isotope concentrations are below the maximum
background in the energy region of each peak should be less
amounts allowable by any regulatory statute.
than ten counts in 60 000 s.
6. Interferences
8. Reagents and Materials
6.1 Thorium, polonium, plutonium, and americium were
6 8.1 Purity of Reagents—Reagent grade chemicals shall be
found not to interfere in this uranium determination. The only
used in all tests. Unless otherwise indicated, it is intended that
possible alpha-emitting isotopes that might interfere, based on
231 4 all reagents shall conform to the specifications of the Commit-
the chemistry of this test method, are Pa (3.28 × 10 y
237 6 teeonAnalyticalReagentsoftheAmericanChemicalSociety.
half-life) and Np (2.16 × 10 y half-life). These isotopes,
Other grades may be used provided it is first ascertained that
however, are not likely to be present in environmental water
samples. Protactinum-231 has the following alpha energies in
MeV, the abundance being given in parentheses: 5.013
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
Bishop, C. T., Casella, V. R., and Glosby,A.A., “Radiometric Method for the listed by the American Chemical Society, see Annual Standards for Laboratory
Determination of Uranium in Water: Single-Laboratory Evaluation and Interlabo- Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
ratory Collaborative Study,” U.S. Environmental Protection Agency Report,EPA and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
600/7-79-093, April 1979. MD.
D3972 − 09 (2015)
the reagent is of sufficiently high purity to permit its use 8.21 Sulfuric Acid 1.8 M (1+9)—Cautiously add with stir-
without reducing the precision, or increasing the bias, of the ring 1 volume of concentrated sulfuric acid (sp gr 1.84) to 9
determination. volumes of water. This solution is 1.8 M.
8.2 Purity of Water—Unless otherwise indicated, reference 8.22 Thymol Blue Indicator Solution—Dissolve 0.04 g of
towatershallbeunderstoodtomeanreagentwaterconforming the sodium salt of thymol blue in 100 mL of water.
to Specifications D1193, Type III, as a minimum.
8.23 Uranium-232 Solution, Standard (about 0.2 Bq/mL).
8.3 RadioactivePurityofReagent—Radioactivepurityshall
9. Precautions
be such that the measured results of blank samples do not
exceedthecalculatedprobableerrorofthemeasurementorare
9.1 Hydrofluoric acid (HF) is very hazardous and should be
within the desired precision.
used in a well-ventilated hood. Wear rubber gloves, safety
glasses or goggles, and a laboratory coat.Avoid breathing any
8.4 Ammonium Hydroxide (sp gr 0.90)—Concentrated am-
HF fumes. Clean up all spills promptly and wash thoroughly
monium hydroxide (NH OH).
after using HF. Ready availability of a topical fluoride binding
8.5 Ammonium Hydroxide Solution 0.15 M (1+99)—Mix 1
agent,suchascalciumgluconategel,isstronglyrecommended
volume of concentrated NH OH (sp gr 0.90) with 99 volumes
in the event of skin contact with HF.
of water. This solution is 0.15 M.
8.6 Anion-Exchange Resin—Stronglybasic,styrene,quater-
10. Sampling
nary ammonium salt, 4% crosslinked, 100 to 200 mesh,
10.1 Collect the sample in accordance with Practices
chloride form.
D1066, D3370, and Specification D1192 as applicable. Pre-
8.7 Electrolyte—Dissolve 132 g of ammonium sulfate in
serve the sample by adjusting the pH to 1 with concentrated
water and dilute to 1 L. Slowly add concentrated NH OH or
HClifthesampleisnottobeanalyzedwithin24h.Recordthe
concentrated H SO while stirring to adjust the pH of the
volume of the sample and the volume of acid added.
2 4
solution to 3.5. The solution is 1 M in (NH ) SO .
4 2 4
11. Calibration and Standardization
8.8 Ethyl Alcohol (C H OH)—Make slightly basic with a
2 5
few drops of concentrated NH OH per 100 mL of alcohol.
11.1 Standardized U is required as a tracer. Before
Anhydrous denatured ethanol is acceptable.
standardization, this isotope must be separated from its radio-
active descendents by anion exchange or some other means of
8.9 Ferric Chloride Carrier Solution (20 mg Fe/mL)—
chemical separation. See Practices D3084 and D3648 for
Dissolve 9.6 g of FeCl ·6H O in 100 mL of 0.5 M HCl.
3 2
generalguidanceconcerningthestandardizationoftracers,and
8.10 Filter paper, ashless, medium porosity.
the energy and efficiency calibrations of the detector. The
pulse-heightanalyzershouldbesettoacceptpulsesfromalpha
8.11 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
chloric acid (HCl). particles of approximately 3.5 to approximately 9.0 MeV in
energy.
8.12 Hydrochloric Acid 8 M (2+1)—Mix 2 volumes of
concentrated HCl (sp gr 1.19) with 1 volume of water. This
12. Procedure
solution is 8 M.
12.1 Coprecipitation:
8.13 Hydrochloric Acid 0.5 M (1+23)—Mix 1 volume of
12.1.1 Measure the volume of approximately 1 L of the
concentrated HCl (sp gr 1.19) with 23 volumes of water.
water sample to be analyzed and transfer to a 2-L beaker.
8.14 Hydrochloric Acid 0.1 M (1+119)—Mix 1 volume of
12.1.2 If the sample has not been acidified, add 5 mL of
concentrated HCl (sp gr 1.19) with 99 volumes of water. This
concentrated HCl.
solution is 0.1 M.
12.1.3 Add a magnetic stirring bar, mix the sample
completely, and check the acidity with pH-indicating paper or
8.15 Hydrofluoric Acid (sp gr 1.2)—Concentrated hydroflu-
strip. If the pH is greater than 1, add concentrated HCl with
oric acid (HF).
mixing until it reaches this value.
8.16 Hydroiodic Acid (sp gr 1.5)—Concentrated hydroiodic
12.1.4 Add approximately 0.2 Bq of standardized U
acid (HI).
tracer with a calibrated pipet or by weight.
8.17 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
12.1.5 If the sample is a seawater or if it may contain
(HNO ).
carbonate ions, it must be boiled for approximately 5 min.
Check t
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D3972 − 09 (Reapproved 2015)
Standard Test Method for
Isotopic Uranium in Water by Radiochemistry
This standard is issued under the fixed designation D3972; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope in Closed Conduits (Withdrawn 2003)
D1193 Specification for Reagent Water
1.1 This test method covers the determination of alpha-
D2777 Practice for Determination of Precision and Bias of
particle-emitting isotopes of uranium in water by means of
Applicable Test Methods of Committee D19 on Water
chemical separations and alpha pulse-height analysis (also
D3084 Practice for Alpha-Particle Spectrometry of Water
known as alpha-particle spectrometry). Uranium is chemically
D3370 Practices for Sampling Water from Closed Conduits
separated from a water sample by coprecipitation with ferrous
D3648 Practices for the Measurement of Radioactivity
hydroxide, anion exchange, and electrodeposition. The test
D5847 Practice for Writing Quality Control Specifications
method applies to soluble uranium as well as to any uranium
for Standard Test Methods for Water Analysis
that might be present in suspended matter in the water sample.
D7282 Practice for Set-up, Calibration, and Quality Control
This test method is applicable for uranium processing effluents
of Instruments Used for Radioactivity Measurements
as well as substitute ocean water. When suspended matter is
present, an acid dissolution step is added to assure that all of
3. Terminology
the uranium dissolves. It is the user’s responsibility to ensure
3.1 Definitions:
the validity of this test method for waters of untested matrices.
3.1.1 For definitions of terms used in this test method, refer
1.2 The values stated in SI units are to be regarded as
to Terminologies C859 and D1129. For terms not included in
4,5
standard. No other units of measurement are included in this
these reference may be made to other published glossaries.
standard.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
4.1 The water sample to be analyzed is acidified and U is
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- added to serve as an isotopic tracer before any additional
operations are performed. If the sample is a seawater sample,
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific warning or if it contains carbonate or bicarbonate ions, the sample must
be boiled under acidic conditions to convert these ions to
statements are given in Section 9.
carbon dioxide gas which is then expelled from the solution.
Carbonate ions must not be present during the precipitation
2. Referenced Documents
step because they complex the uranium and prevent its
2.1 ASTM Standards:
coprecipitation. The uranium is coprecipitated from the sample
C859 Terminology Relating to Nuclear Materials
with ferrous hydroxide. This precipitate is dissolved in con-
C1163 Practice for Mounting Actinides for Alpha Spectrom-
centrated hydrochloric acid, or is subjected to an acid dissolu-
etry Using Neodymium Fluoride
tion with concentrated nitric and hydrofluoric acids if the
D1066 Practice for Sampling Steam
hydrochloric acid fails to dissolve the precipitate.
D1129 Terminology Relating to Water
4.2 The uranium is separated from other radionuclides by
D1192 Guide for Equipment for Sampling Water and Steam
adsorption on anion-exchange resin from 8 M hydrochloric
acid, followed by elution with 0.1 M hydrochloric acid. The
uranium is electrodeposited onto a stainless steel disk. Isotopic
This test method is under the jurisdiction of ASTM Committee D19 on Water
uranium radioactivities are measured by alpha pulse-height
and is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-
cal Analysis.
Current edition approved Jan. 1, 2015. Published January 2015. Originally
approved in 1980. Last previous edition approved in 2009 as D3972 – 09. DOI: The last approved version of this historical standard is referenced on
10.1520/D3972-09R15. www.astm.org.
2 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Parker, S. P., ed., Dictionary of Chemical Terms, McGraw-Hill Book Co., New
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM York, NY, 1985.
Standards volume information, refer to the standard’s Document Summary page on IUPAC, “Glossary of Terms Used in Nuclear Analytical Chemistry,” Pure and
the ASTM website. Applied Chemistry, Vol 54, 1982, pp. 1533–1554.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3972 − 09 (2015)
TABLE 1 Relevant Properties of Uranium Isotopes of Interest in
(25.4 %), 5.03 (23 %), 4.951 (22.5 %), 5.059 (11 %), and 4.734
A
Environmental Waters
(8.4 %). Thus, from Table 1, it is seen that Pa can interfere
Half Life Principal Alpha Energies in MeV 233 234
with the determination of U or U. However, when the
Isotope
Years (Abundance)
4.951 to 5.059 MeV Pa peaks can be resolved from the
U 68.9 5.320 (68.6)
uranium peaks, a correction can be made. Neptunium-237 has
5.262 (31.4)
alpha emission energies ranging from 4.639 to 4.873 MeV,
233 5
U 1.592 × 10 4.824 (83.3)
with 72 % found between 4.771 and 4.788 MeV. Conventional
4.782 (14.1)
analytical equipment would not be able to resolve these peaks
234 5
from normal U emissions. If Np-237 is suspected to be
U 2.455 × 10 4.774 (72.5)
4.722 (27.5)
present in the sample, a separate Np analysis would be
required to make the appropriate correction to the U result.
235 8
U 7.038 × 10 4.596 (5.6)
4.307 (57)
6.2 When measuring very low concentrations of uranium
4.366 (17)
isotopes in environmental samples, detector backgrounds and
4.214 (6.4)
laboratory blanks must be well known. Blank determinations
236 7
U 2.342 × 10 4.493 (74)
are made to ascertain that any contamination from reagents,
4.445 (26)
glassware and other laboratory apparatus is small compared to
238 9
U 4.468 × 10 4.198 (77) the activity in the sample that is being analyzed. A blank
4.151 (23)
determination should be made in exactly the same way as the
A
Table of Isotopes, Eighth Edition, Vol. 11, Richard B. Firestone, Lawrence
sample determination.
Berkeley National Laboratory, University of California, 1996.
7. Apparatus
7.1 Centrifuge, 250-mL centrifuge bottle or tube capacity.
analysis with a silicon surface-barrier or ion-implanted detector
7.2 Ion Exchange Column, glass or plastic, approximately
and a multichannel analyzer.
13-mm inside diameter and 150 mm long with a glass-wool
4.3 When U is used as the tracer, the other isotopes of
plug or plastic frit and a 100- to 150-mL reservoir.
uranium listed in Table 1 can be detected in the alpha-particle
spectrum of an unknown sample. From the alpha energies 7.3 Electrodeposition Apparatus, consisting of a 0 to 12-V,
0 to 2-A power supply (preferably constant current) and an
given in the table, it can be seen that the alpha energy of U
is more than 0.40 MeV higher than the energy of any other electrodeposition cell. The cathode is an approximately 20-mm
diameter stainless steel disk polished to a mirror finish. The
uranium isotope. Thus, there should be little interference from
232 233
tailing of the U into the lower energy alpha peaks. U anode is approximately 1-mm diameter platinum wire with an
and U usually cannot be resolved because their principal approximately 8-mm diameter loop at the end of the wire
235 236
alpha energies differ by only 0.04 MeV. U and U peaks parallel to the cathode disk. Cooling of the electrolyte during
can be resolved only with difficulty. The alpha peaks from electrodeposition to at least 50°C is recommended. See refer-
other combinations of uranium isotopes can be resolved unless ences in Section 8 of Practice D3084 for more details.
the quality of the finally prepared sample is poor.
7.4 Alpha Pulse-Height Analysis System, consisting of a
silicon surface-barrier or ion-implanted detector, supporting
5. Significance and Use
electronics, and pulse-height analyzer. A system capable of
5.1 This test method was developed to measure the radio-
giving a resolution of 30 keV FWHM or better, when measured
activity of uranium isotopes in environmental waters or waters
with a high-quality source, is recommended. The counting
released to the environment, and to determine whether the
efficiency of the system should be greater than 15 %, and the
uranium-isotope concentrations are below the maximum
background in the energy region of each peak should be less
amounts allowable by any regulatory statute.
than ten counts in 60 000 s.
6. Interferences
8. Reagents and Materials
6.1 Thorium, polonium, plutonium, and americium were
6 8.1 Purity of Reagents—Reagent grade chemicals shall be
found not to interfere in this uranium determination. The only
used in all tests. Unless otherwise indicated, it is intended that
possible alpha-emitting isotopes that might interfere, based on
231 4 all reagents shall conform to the specifications of the Commit-
the chemistry of this test method, are Pa (3.28 × 10 y
237 6 tee on Analytical Reagents of the American Chemical Society.
half-life) and Np (2.16 × 10 y half-life). These isotopes,
Other grades may be used provided it is first ascertained that
however, are not likely to be present in environmental water
samples. Protactinum-231 has the following alpha energies in
MeV, the abundance being given in parentheses: 5.013
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
Bishop, C. T., Casella, V. R., and Glosby, A. A., “Radiometric Method for the listed by the American Chemical Society, see Annual Standards for Laboratory
Determination of Uranium in Water: Single-Laboratory Evaluation and Interlabo- Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
ratory Collaborative Study,” U.S. Environmental Protection Agency Report, EPA and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
600/7-79-093, April 1979. MD.
D3972 − 09 (2015)
the reagent is of sufficiently high purity to permit its use 8.21 Sulfuric Acid 1.8 M (1+9)—Cautiously add with stir-
without reducing the precision, or increasing the bias, of the ring 1 volume of concentrated sulfuric acid (sp gr 1.84) to 9
determination. volumes of water. This solution is 1.8 M.
8.2 Purity of Water—Unless otherwise indicated, reference 8.22 Thymol Blue Indicator Solution—Dissolve 0.04 g of
to water shall be understood to mean reagent water conforming the sodium salt of thymol blue in 100 mL of water.
to Specifications D1193, Type III, as a minimum.
8.23 Uranium-232 Solution, Standard (about 0.2 Bq/mL).
8.3 Radioactive Purity of Reagent—Radioactive purity shall
9. Precautions
be such that the measured results of blank samples do not
exceed the calculated probable error of the measurement or are
9.1 Hydrofluoric acid (HF) is very hazardous and should be
within the desired precision.
used in a well-ventilated hood. Wear rubber gloves, safety
glasses or goggles, and a laboratory coat. Avoid breathing any
8.4 Ammonium Hydroxide (sp gr 0.90)—Concentrated am-
HF fumes. Clean up all spills promptly and wash thoroughly
monium hydroxide (NH OH).
after using HF. Ready availability of a topical fluoride binding
8.5 Ammonium Hydroxide Solution 0.15 M (1+99)—Mix 1
agent, such as calcium gluconate gel, is strongly recommended
volume of concentrated NH OH (sp gr 0.90) with 99 volumes
in the event of skin contact with HF.
of water. This solution is 0.15 M.
8.6 Anion-Exchange Resin—Strongly basic, styrene, quater-
10. Sampling
nary ammonium salt, 4 % crosslinked, 100 to 200 mesh,
10.1 Collect the sample in accordance with Practices
chloride form.
D1066, D3370, and Specification D1192 as applicable. Pre-
8.7 Electrolyte—Dissolve 132 g of ammonium sulfate in
serve the sample by adjusting the pH to 1 with concentrated
water and dilute to 1 L. Slowly add concentrated NH OH or
HCl if the sample is not to be analyzed within 24 h. Record the
concentrated H SO while stirring to adjust the pH of the
volume of the sample and the volume of acid added.
2 4
solution to 3.5. The solution is 1 M in (NH ) SO .
4 2 4
11. Calibration and Standardization
8.8 Ethyl Alcohol (C H OH)—Make slightly basic with a
2 5
few drops of concentrated NH OH per 100 mL of alcohol.
11.1 Standardized U is required as a tracer. Before
Anhydrous denatured ethanol is acceptable.
standardization, this isotope must be separated from its radio-
active descendents by anion exchange or some other means of
8.9 Ferric Chloride Carrier Solution (20 mg Fe/mL)—
chemical separation. See Practices D3084 and D3648 for
Dissolve 9.6 g of FeCl ·6H O in 100 mL of 0.5 M HCl.
3 2
general guidance concerning the standardization of tracers, and
8.10 Filter paper, ashless, medium porosity.
the energy and efficiency calibrations of the detector. The
8.11 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro- pulse-height analyzer should be set to accept pulses from alpha
chloric acid (HCl). particles of approximately 3.5 to approximately 9.0 MeV in
energy.
8.12 Hydrochloric Acid 8 M (2+1)—Mix 2 volumes of
concentrated HCl (sp gr 1.19) with 1 volume of water. This
12. Procedure
solution is 8 M.
12.1 Coprecipitation:
8.13 Hydrochloric Acid 0.5 M (1+23)—Mix 1 volume of
12.1.1 Measure the volume of approximately 1 L of the
concentrated HCl (sp gr 1.19) with 23 volumes of water.
water sample to be analyzed and transfer to a 2-L beaker.
8.14 Hydrochloric Acid 0.1 M (1+119)—Mix 1 volume of
12.1.2 If the sample has not been acidified, add 5 mL of
concentrated HCl (sp gr 1.19) with 99 volumes of water. This
concentrated HCl.
solution is 0.1 M.
12.1.3 Add a magnetic stirring bar, mix the sample
completely, and check the acidity with pH-indicating paper or
8.15 Hydrofluoric Acid (sp gr 1.2)—Concentrated hydroflu-
strip. If the pH is greater than 1, add concentrated HCl with
oric acid (HF).
mixing until it reaches this value.
8.16 Hydroiodic Acid (sp gr 1.5)—Concentrated hydroiodic
12.1.4 Add approximately 0.2 Bq of standardized U
acid (HI).
tracer with a calibrated pipet or by weight.
8.17 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
12.1.5 If the sample is a seawater or if it may contain
(HNO
...
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