ASTM D7283-06
(Test Method)Standard Test Method for Alpha- And Beta- Activity in Water By Liquid Scintillation Counting
Standard Test Method for Alpha- And Beta- Activity in Water By Liquid Scintillation Counting
SIGNIFICANCE AND USE
This test method is intended for the measurement of gross alpha- and beta-activity concentrations in the analyses of environmental and drinking waters.
This test method is also applicable to the direct analysis of gross alpha- and beta-activity concentrations in water when low detection limits are not required. Direct analysis provides a rapid method for determination of gross alpha- and beta-activity concentrations when low detection limits are not required.
This test method is not capable of discriminating among alpha emitting radionuclides or among beta emitting radionuclides. Those intending to identify and quantify specific radionuclides should use test methods specific to the radionuclides of interest.
This test method may not be cited as a method for the determination of gross alpha- or beta-activity concentrations in a solid/soil matrix or the acid digestate of the same. The use of this test method for such applications brings the potential for serious bias and incomparability of results dependent on the manner of sample preparation or treatment, or both.
SCOPE
1.1 This test method covers the measurement of gross alpha- and beta- activity concentrations in a homogeneous water sample. It is applicable to alpha emitters with activity concentration levels above 0.037 Bq/L (1 pCi/L) and beta emitters with activity concentration levels above 0.15 Bq/L (4 pCi/L). This test method is not applicable to samples containing radionuclides that are volatile under conditions of the analysis.
1.2 This test method may also be used for the direct measurement of gross alpha- and beta- activity concentrations in homogeneous water samples with alpha emitter activity concentration levels above 1.8 Bq/L (50 pCi/L) and beta emitter activity concentration levels above 3.7 Bq/L (100 pCi/L).
1.3 This test method was tested using a single-operator test. Round-robin testing is currently in progress on this test method.
1.4 Standard methods under the jurisdiction of ASTM Committee D19 may be published for a limited time preliminary to the completion of full collaborative study validation. Such standards are deemed to have met all other D19 qualifying requirements but have not completed the required validation studies to fully characterize the performance of the Test Method across multiple laboratories and matrices. Preliminary publication is done to make current technology accessible to users of standards, and to solicit additional input from the user community.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
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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: D7283 − 06
StandardTest Method for
Alpha- And Beta- Activity in Water By Liquid Scintillation
Counting
This standard is issued under the fixed designation D7283; 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 responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method covers the measurement of gross
bility of regulatory limitations prior to use.
alpha- and beta- activity concentrations in a homogeneous
water sample. It is applicable to alpha emitters with activity
2. Referenced Documents
concentration levels above 0.037 Bq/L (1 pCi/L) and beta
emitters with activity concentration levels above 0.15 Bq/L (4
2.1 ASTM Standards:
pCi/L). This test method is not applicable to samples contain-
D1129Terminology Relating to Water
ing radionuclides that are volatile under conditions of the
D1125Test Methods for Electrical Conductivity and Resis-
analysis.
tivity of Water
1.2 This test method may also be used for the direct
D1193Specification for Reagent Water
measurement of gross alpha- and beta- activity concentrations
D1890Test Method for Beta Particle Radioactivity ofWater
in homogeneous water samples with alpha emitter activity
D1943Test Method for Alpha Particle Radioactivity of
concentration levels above 1.8 Bq/L (50 pCi/L) and beta
Water
emitter activity concentration levels above 3.7 Bq/L (100
D3370Practices for Sampling Water from Closed Conduits
pCi/L).
D3648Practices for the Measurement of Radioactivity
1.3 Thistestmethodwastestedusingasingle-operatortest.
D3856Guide for Management Systems in Laboratories
Round-robin testing is currently in progress on this test
Engaged in Analysis of Water
method.
D4448Guide for Sampling Ground-Water MonitoringWells
1.4 Standard methods under the jurisdiction of ASTM Com- D5847Practice for Writing Quality Control Specifications
mittee D19 may be published for a limited time preliminary to
for Standard Test Methods for Water Analysis
the completion of full collaborative study validation. Such
D6001Guide for Direct-Push Ground Water Sampling for
standards are deemed to have met all other D19 qualifying
Environmental Site Characterization
requirements but have not completed the required validation
2.2 Other Standards and Publications
studies to fully characterize the performance of the Test
EPA 900.0Gross Alpha and Gross Beta Radioactivity in
Method across multiple laboratories and matrices. Preliminary
DrinkingWater,from Prescribed Procedures for Measure-
publication is done to make current technology accessible to
ment of Radioactivity in Drinking Water (EPA-600/4-80-
users of standards, and to solicit additional input from the user
032)
community.
StandardMethods7110C CoprecipitationMethodforGross
1.5 The values stated in SI units are to be regarded as
Alpha Radioactivity in Drinking Water
standard. No other units of measurement are included in this
Standard Methods 8010ETable8010: Recommended Com-
standard.
position for Reconstituted Fresh Water
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
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
This test method is under the jurisdiction ofASTM Committee D19 on Water Standards volume information, refer to the standard’s Document Summary page on
andisthedirectresponsibilityofSubcommitteeD19.04onMethodsofRadiochemi- the ASTM website.
cal Analysis. Available from United States Environmental Protection Association (EPA),
CurrenteditionapprovedDec.15,2006.PublishedJanuary2007.DOI:10.1520/ Ariel Rios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http://
D7283-06. www.epa.gov.
2 5
Wong,C.T.,Soliman,V.M.,andPerera,S.K., Journal of Radioanalytical and Available fromAmericanWaterWorksAssociation (AWWA), 6666W. Quincy
Nuclear Chemistry, Vol. 264, No. 2, 2005, pp. 357–363. Ave., Denver, CO 80235, http://www.awwa.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7283 − 06
ISO 9696Water Quality—Measurement of Gross Alpha 4. Summary of Test Method
Activity in Non-saline Water—Thick Source Method
4.1 Thetestsampleisreducedbyevaporation,transferredto
ascintillationvialandmixedwithasuitableliquidscintillation
3. Terminology
cocktail. Gross alpha- and beta- activity concentrations are
3.1 Definitions of Terms Specific to This Standard:
measured simultaneously by liquid scintillation using alpha/
3.1.1 alpha-to-beta spillover, n—in the measurement of
beta discrimination. By optimizing the alpha/beta discrimina-
radioactivity, that fraction of alpha particles emitted by a
tor, a high efficiency of alpha- and beta- particle detection can
source which are misclassified as beta particles.
be achieved with acceptable misclassification of beta particles
3.1.2 alpha particle detection effıciency, n—in the measure-
into the alpha multi-channel analyzer (MCA) and alpha par-
ment of radioactivity,thatfractionofalphaparticlesemittedby ticles into the beta MCA.The alpha- and beta-particle efficien-
a source which are identified as alpha particles by the counter.
cies and crosstalk calibrations of the liquid scintillation system
are determined by using known activities of established refer-
3.1.3 beta-to-alpha spillover, n—in the measurement of
encenuclidesintestsourceshavingresidualsolidscontentand
radioactivity,thatfractionofbetaparticlesemittedbyasource
cocktail-solvent ratio comparable to that of the test samples.
which are misclassified as alpha particles.
Some commonly employed reference standards in-
3.1.4 beta energy, maximum, n—themaximumenergyofthe
239 230
clude Am, Pu, Th, natural isotopic abundance uranium
beta particle energy spectrum produced during beta decay of a
234 235 238 90 90 137
( U, U, and U), Sr/ Y, and Cs. Results are re-
given radionuclide.
ported in activity units equivalent along with the reference
3.1.4.1 Discussion—Since a given beta emitter may decay
radionuclide (e.g., Bq/L gross alpha equiv. Th).
to several different nuclear energy levels of the progeny, more
4.2 When low detection limits are not required, an aliquant
than one maximum energy may be listed for a given radionu-
of the sample is mixed directly with a suitable liquid scintil-
clide.
lation cocktail for analysis.
3.1.5 beta particle detection effıciency, n—in the measure-
ment of radioactivity, that fraction of beta particles emitted by
5. Significance and Use
a source which are identified as beta particles by the counter.
5.1 This test method is intended for the measurement of
3.1.6 detector background, n—in the measurement of radio-
gross alpha- and beta-activity concentrations in the analyses of
activity, the counting rate resulting from factors other than the
environmental and drinking waters.
radioactivity of the sample and reagents used.
3.1.6.1 Discussion—Detector background varies with the
5.2 This test method is also applicable to the direct analysis
location, shielding of the detector, and the electronics; it
of gross alpha- and beta-activity concentrations in water when
includes cosmic rays, contaminating radioactivity, and elec-
low detection limits are not required. Direct analysis provides
tronic noise.
a rapid method for determination of gross alpha- and beta-
activity concentrations when low detection limits are not
3.1.7 figure of merit, n—a numerical quantity based on one
required.
or more characteristics of a system or device that represents a
measure of efficiency or effectiveness. Generally calculated as
5.3 Thistestmethodisnotcapableofdiscriminatingamong
the square of the efficiency divided by the background.
alpha emitting radionuclides or among beta emitting radionu-
3.1.8 homogeneous water sample, n—water in which the
clides. Those intending to identify and quantify specific radio-
alpha and beta activity is uniformly dispersed throughout the
nuclides should use test methods specific to the radionuclides
volume of water sample and remains so until the measurement
of interest.
is completed or until the sample is evaporated or precipitating
5.4 This test method may not be cited as a method for the
reagents are added to the sample.
determinationofgrossalpha-orbeta-activityconcentrationsin
3.1.9 reagent background, n—in the measurement of radio-
a solid/soil matrix or the acid digestate of the same.The use of
activity of water samples, the counting rate observed when a
this test method for such applications brings the potential for
sample is replaced by mock sample salts or by reagent
serious bias and incomparability of results dependent on the
chemicals used for chemical separations that contain no
manner of sample preparation or treatment, or both.
analyte.
3.1.9.1 Discussion—Reagent background varies with the
6. Interferences
reagent chemicals and analytical methods used and may vary
6.1 The counting efficiencies for both the alpha and beta
with reagents from different manufacturers and from different
components are dependent on the energy of the alpha- or
processing lots.
beta-emitter chosen to determine the calibration coefficient.
3.2 Definitions—For definitions of terms used in this test
Biases may occur if the energies of the alpha- or beta-particle
method, refer to Terminology D1129. For terms not defined in
emitting nuclides in the test sample differs significantly from
this test method or in Terminology D1129, reference may be
those used to determine the respective counting efficiencies.
made to other published glossaries.
Bestresultsareobtainedwhentheradionuclidecompositionof
the sample is known and the calibration radionuclide is
selected to match as closely as possible the energy of the
Available from International Organization for Standardization (ISO), 1 rue de
Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch. sample radionuclide.
D7283 − 06
137 137m
6.2 The use of Cs/ Ba as a calibration standard for tionaluncertaintyinspillovercorrections.Quenchingiscaused
samples containing radionuclides other than Cs may intro- by molecular species in the sample and cocktail mixture that
duce a low bias in the analytical results unless there is a reduce the intermolecular transfer of energy or absorb emitted
correction for conversion electron emissions. The conversion visible and UV photons prior to detection. This test method
137m
electrons from the Ba progeny are detected by liquid describes the use of an external standard source to minimize
scintillation yielding greater than 100% detection efficiency the effects of quenching.
137 137m
for the Cs/ Ba calibration standard.
6.9 The presence of solid particles in the scintillation
cocktail may lead to erroneous results. This test method
6.3 When using uranium as a calibration standard the
234 235
requirescompletedissolutionofthesamplepriortoadditionof
isotopic abundance of each of the isotopes ( U, U,
the scintillation cocktail.
and U) must be known to accurately determine the standard
activity concentration. Many uranium standards used for mass
6.10 Thesamplealiquant/scintillationcocktailmixtureratio
measurements are depleted uranium. Natural isotopic abun-
should be within the cocktail manufacteurer’s recommenda-
dance uranium and depleted uranium standards contain short-
tions to insure a homogeneous mixture. If the sample aliquant/
234 234m
lived decay progeny ( Th, Pa) which interfere with the
scintillation cocktail mixture forms two phases, repeat the
spillovercalibrationunlesstheyareremovedimmediatelyprior
analysis with a different sample aliquant/scintillation cocktail
to calibration.
mixture/ratio.
6.4 Radon is a noble gas, and therefore easily emanates
6.11 Theexteriorofthevialsmustbefreeofdirt,markings,
from most matrices. If the radon progeny of the uranium
and fingerprints.
222 220 219
( Rn), thorium ( Rn), and actinium ( Rn) series emanate
6.12 ‘Dark adapting’ of scintillator solutions is dependent
priortodecaying,transientequilibriumisdisrupted.EPA900.0
uponthefluor,theinstrumentandthelightingconditionsofthe
recognizes this disruption by suggesting a delay of 72 h before
count room. Evaluation of these parameters for the adaptation
the prepared sample is counted for gross alpha. Other pub-
to the ‘dark’conditions is necessary for counting optimization.
lished methods such as Standard Methods 7110C provide for a
6.13 Samples and standards should be counted with the
shorter delay of 3 h. This test method advises that any such
same instrument operating parameters including temperature.
delay period used by the laboratory be based on the measure-
For refrigerated instruments, time should be allowed for the
ment quality objectives inherent in the intended data use (see
samples to cool to the operating temperature of the instrument.
11.7).
Be aware of the potential for phase separation when cooling
6.5 Radionuclides may be present in the sample in disequi-
prepared samples.
librium with their parent radionuclides. Many factors, includ-
ing preferential dissolution from the natural matrix in which
7. Apparatus
the parent radionuclide occurs can cause this disequilibrium.
7.1 Liquid Scintillation vials, approximately 20 mL, of
Wheretheseradionuclideshaveahalf-lifeontheorderofafew
low-potassium glass are recommended.
days or shorter, the time elapsed between sampling and the
7.2 Electric hot plate.
beginning of sample counting will tend to bias the final result
low.Inthosecasesthemeasurementqualityobjectivesinherent
7.3 Glassware.
in the intended data may dictate the maximum time between
7.4 Transfer pipettes.
sample collection and the beginning of sample counting. The
7.5 Liquid scintillation counting system, coincidence-type
laboratory should be aware of such requirements and be
with alpha/beta discrimination. A guard detector or other
prepared to comply with them.
background reduction electronics or software may be incorpo-
6.6 Radionuclides incorporated in volatile compounds are
rated to reduce the instrument background.
lost during the conduct of this test method. These include
tritium in HTO or C in the carbon dioxide formed during the 8. Reagents and Materials
2−
additionofacid.Thepertechnetateion(TcO )isanexample
8.1 Purity of Reagents—Reagent grade chemicals shall be
of a radionuclide which may be lost through semi-volatility.
used in all tests. Unless
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