ASTM D2460-07
(Test Method)Standard Test Method for Alpha-Particle-Emitting Isotopes of Radium in Water
Standard Test Method for Alpha-Particle-Emitting Isotopes of Radium in Water
SIGNIFICANCE AND USE
Radium is one of the most radiotoxic elements. Its isotope of mass 226 is the most hazardous because of its long half-life. The isotopes 223 and 224, although not as hazardous, are of some concern in appraising the quality of water.
The alpha-particle-emitting isotopes of radium other than that of mass 226 may be determined by difference if radium-226 is measured separately, such as by Test Method D 3454. Note that one finds 226Ra and 223Ra together in variable proportions (5, 6), but 224Ra does not normally occur with them. Thus, 223Ra often may be determined by simply subtracting the 226Ra content from the total: and if 226Ra and 223Ra are low, 224Ra may be determined directly. The determination of a single isotope in a mixture is less precise than if it occurred alone.
SCOPE
1.1 This test method covers the separation of dissolved radium from water for the purpose of measuring its radioactivity. Although all radium isotopes are separated, the test method is limited to alpha-particle-emitting isotopes by choice of radiation detector. The most important of these radioisotopes are 223Ra, 224Ra, and 226Ra. The lower limit of concentration to which this test method is applicable is 3.7 x 10-2 Bq/L (1 pCi/L).
1.2 This test method may be used for absolute measurements by calibrating with a suitable alpha-emitting radioisotope such as 226Ra, or for relative methods by comparing measurements with each other. Mixtures of radium isotopes may be reported as equivalent 226Ra. Information is also provided from which the relative contributions of radium isotopes may be calculated.
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. For a specific precautionary statement, see Section 9.
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Standards Content (Sample)
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Designation: D2460 − 07
StandardTest Method for
1
Alpha-Particle-Emitting Isotopes of Radium in Water
This standard is issued under the fixed designation D2460; 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 D3454Test Method for Radium-226 in Water
D3648Practices for the Measurement of Radioactivity
1.1 This test method covers the separation of dissolved
D4448GuideforSamplingGround-WaterMonitoringWells
radium from water for the purpose of measuring its radioac-
D5847Practice for Writing Quality Control Specifications
tivity. Although all radium isotopes are separated, the test
for Standard Test Methods for Water Analysis
method is limited to alpha-particle-emitting isotopes by choice
D6001Guide for Direct-Push Ground Water Sampling for
ofradiationdetector.Themostimportantoftheseradioisotopes
223 224 226 Environmental Site Characterization
are Ra, Ra,and Ra.Thelowerlimitofconcentrationto
-2
which this test method is applicable is 3.7 × 10 Bq/L
3. Terminology
(1pCi/L).
3.1 Definition:
1.2 This test method may be used for absolute measure-
3.1.1 For definitions of terms used in this standard, see
ments by calibrating with a suitable alpha-emitting radioiso-
Terminologies C859 and D1129. For terms not included in
226
tope such as Ra, or for relative methods by comparing
these, reference may be made to other published glossaries (1,
measurements with each other. Mixtures of radium isotopes
3
2).
226
may be reported as equivalent Ra. Information is also
provided from which the relative contributions of radium
4. Summary of Test Method
isotopes may be calculated.
4.1 Radium is collected from the water by coprecipitation
1.3 This standard does not purport to address all of the
with mixed barium and lead sulfates. The barium and lead
safety concerns, if any, associated with its use. It is the
carriers are added to a solution containing alkaline citrate ion
responsibility of the user of this standard to establish appro-
which prevents precipitation until interchange has taken place.
priate safety and health practices and determine the applica-
Sulfuric acid is then used to precipitate the sulfates, which are
bility of regulatory limitations prior to use. For a specific
purified by nitric acid washes. The precipitate is dissolved in
precautionary statement, see Section 9.
ammoniacal EDTA. The barium and radium sulfates are
reprecipitatedbytheadditionofaceticacid,therebyseparating
2. Referenced Documents
them from lead and other radionuclides. The precipitate is
2
2.1 ASTM Standards: dried on a planchet, weighed to determine the chemical yield,
C859Terminology Relating to Nuclear Materials
and alpha-counted to determine the total disintegration rate of
D1129Terminology Relating to Water alpha-particle-emitting radium isotopes. This procedure is
D1193Specification for Reagent Water
based upon published ones (3, 4).
D1943Test Method for Alpha Particle Radioactivity of
5. Significance and Use
Water
D2777Practice for Determination of Precision and Bias of
5.1 Radium is one of the most radiotoxic elements. Its
Applicable Test Methods of Committee D19 on Water
isotope of mass 226 is the most hazardous because of its long
D3370Practices for Sampling Water from Closed Conduits
half-life.Theisotopes223and224,althoughnotashazardous,
are of some concern in appraising the quality of water.
5.2 The alpha-particle-emitting isotopes of radium other
1
This test method is under the jurisdiction ofASTM Committee D19 on Water
than that of mass 226 may be determined by difference if
andisthedirectresponsibilityofSubcommitteeD19.04onMethodsofRadiochemi-
cal Analysis. radium-226 is measured separately, such as by Test Method
226 223
Current edition approved June 15, 2007. Published July 2007. Originally
D3454.Notethatonefinds Raand Ratogetherinvariable
approvedin1966.ReplacesD2460–66T.Lastpreviouseditionapprovedin2005as
224
proportions (5, 6), but Ra does not normally occur with
D2460–05. DOI: 10.1520/D2460-07.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
the ASTM website. this standard.
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D2460 − 07
223
them. Thus, Ra often may be determined by simply sub- 7. Apparatus
226 226 223
tractingthe Racontentfromthetota
...
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