1、Designation: D7283 13D7283 17Standard Test Method forAlpha and Beta Activity in Water By Liquid ScintillationCounting1This standard is issued under the fixed designation D7283; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of gross alpha- and beta- activity concentrations in a homogeneous water
3、 sample.It is applicable to alpha emitters with activity concentration levels above 0.11 Bq/L (3 pCi/L) and beta emitters with activityconcentration levels above 0.15 Bq/L (4 pCi/L). This test method is not applicable to samples containing radionuclides that arevolatile under conditions of the analy
4、sis.1.2 This test method may also be used for the direct measurement of gross alpha- and beta- activity concentrations inhomogeneous water samples with alpha emitter activity concentration levels above 1.8 Bq/L (50 pCi/L) and beta emitter activityconcentration levels above 3.7 Bq/L (100 pCi/L).1.3 T
5、his test method was tested using single-operator tests.2,3 A collaborative study following the U.S. EPA “Protocol for theEvaluation of Alternate Test Procedures for Analyzing Radioactive Contaminants in Drinking Water” was performed. The resultsof this study are on file at ASTM Headquarters.41.4 Sta
6、ndard methods under the jurisdiction of ASTM Committee D19 may be published for a limited time preliminary to thecompletion of full collaborative study validation. Such standards are deemed to have met all other D19 qualifying requirementsbut have not completed the required validation studies to ful
7、ly characterize the performance of the Test Method across multiplelaboratories and matrices. Preliminary publication is done to make current technology accessible to users of standards, and tosolicit additional input from the user community.1.4 The values stated in SI units are to be regarded as sta
8、ndard. No other units of measurement are included in thisThe valuesgiven in parentheses are mathematical conversions to pCi/Lthat are provided for information only and are not considered standard.An exception is noted in Section 14standard1.5 This standard does not purport to address all of the safe
9、ty concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.6 This international standard was developed in accordance with international
10、ly recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:5D1129 Terminolo
11、gy Relating to WaterD1125 Test Methods for Electrical Conductivity and Resistivity of WaterD1193 Specification for Reagent WaterD1890 Test Method for Beta Particle Radioactivity of Water1 This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Su
12、bcommittee D19.04 on Methods of RadiochemicalAnalysis.Current edition approved Feb. 1, 2013June 1, 2017. Published April 2013June 2017. Originally approved in 2006. Last previous edition approved in 20062013 as D7283 06.13. DOI: 10.1520/D7283-13.10.1520/D7283-17.2 Wong, C. T., Soliman, V. M., and Pe
13、rera, S. K., Journal of Radioanalytical and Nuclear Chemistry, Vol 264, No. 2, 2005, pp. 357363.3 Ruberu, S.R., Liu, Y.G., and Perera, S.K., Health Physics, Vol 95, No. 4, October 2008, pp. 397406.4 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting
14、Research Report RR:D19-1195. Contact ASTM CustomerService at serviceastm.org.5 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on t
15、he ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users c
16、onsult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D1943 Test Method for Alpha Part
17、icle Radioactivity of WaterD3370 Practices for Sampling Water from Closed ConduitsD3648 Practices for the Measurement of RadioactivityD3856 Guide for Management Systems in Laboratories Engaged in Analysis of WaterD4448 Guide for Sampling Ground-Water Monitoring WellsD5847 Practice for Writing Qualit
18、y Control Specifications for Standard Test Methods for Water AnalysisD6001 Guide for Direct-Push Groundwater Sampling for Environmental Site CharacterizationD7902 Terminology for Radiochemical AnalysesE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conduct
19、ing an Interlaboratory Study to Determine the Precision of a Test Method2.2 Other Standards and Publications:EPA 900.0 Gross Alpha and Gross Beta Radioactivity in Drinking Water, from Prescribed Procedures for Measurement ofRadioactivity in Drinking Water (EPA-600/4-80-032)6Standard Methods 7110C Co
20、precipitation Method for Gross Alpha Radioactivity in Drinking Water7Standard Methods 8010E Table 8010: Recommended Composition for Reconstituted Fresh Water7ISO 9696 Water QualityMeasurement of Gross Alpha Activity in Non-saline WaterThick Source Method8ISO 11704:2010 Water QualityMeasurement of Gr
21、oss Alpha and Beta Activity Concentration in non-saline water LiquidScintillation Counting Method83. Terminology3.1 DefinitionsFor definitions of terms used in this test method, refer to TerminologyTerminologies D1129 or D7902. Forterms not defined in this test method or in Terminology D1129, refere
22、nce may be made to other published glossaries.3.2 Definitions of Terms Specific to This Standard:3.2.1 alpha-to-beta spillover, nin the measurement of radioactivity, for a given emitting source, that fraction of alpha particlesthat are misclassified as beta particles by the counter.3.2.2 alpha parti
23、cle detection effciency, nin the measurement of radioactivity, for a given emitting source, that fraction ofalpha particles that are identified as alpha particles by the counter.3.2.3 beta-to-alpha spillover, nin the measurement of radioactivity, for a given emitting source, that fraction of beta pa
24、rticlesthat are misclassified as alpha particles by the counter.3.2.4 beta energy, maximum, nthe maximum energy of the beta particle energy spectrum produced during beta decay of agiven radionuclide.3.2.4.1 DiscussionSince a given beta emitter may decay to several different nuclear energy levels of
25、the progeny, more than one maximum energymay be listed for a given radionuclide.3.2.5 beta particle detection effciency, nin the measurement of radioactivity, for a given emitting source, that fraction of betaparticles that are identified as beta particles by the counter.3.2.6 detector background, n
26、in the measurement of radioactivity, the counting rate resulting from factors other than theradioactivity of the sample and reagents used.3.2.6.1 DiscussionDetector background varies with the location, shielding of the detector, and the electronics; such background includes cosmic rays,contaminating
27、 radioactivity, and electronic noise.3.2.7 figure of merit, na numerical quantity based on one or more characteristics of a system or device, representing a measureof efficiency or effectiveness; figure of merit is generally calculated as the square of the efficiency divided by the background.3.2.8
28、gross alpha, nin the measurement of radioactivity, a semi-quantitative estimate of the combined activity ofalpha-emitting radionuclides in a test sample.6 Available from United States Environmental Protection Association (EPA), Ariel Rios Agency (EPA), William Jefferson Clinton Bldg., 1200 Pennsylva
29、nia Ave., NW,Washington, DC 20460, http:/www.epa.gov.7 Available from American Water Works Association (AWWA), 6666 W. Quincy Ave., Denver, CO 80235, http:/www.awwa.org.8 Available from International Organization for Standardization (ISO), 1 rue de Varemb, Case postale 56, CH-1211, Geneva 20, Switze
30、rland, http:/www.iso.ch.ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland, http:/www.iso.org.D7283 1723.2.9 gross beta, nin the measurement of radioactivity, a semi-quantitative estimate of the combined activity of beta-emittingradionuclides in a test
31、 sample.3.2.10 homogeneous water sample, nwater in which the alpha and beta activity is uniformly dispersed throughout the volumeof water sample and remains so until the measurement is completed or until the sample is evaporated or precipitating reagents areadded to the sample.3.2.11 reagent backgro
32、und, nin the measurement of radioactivity of water samples, the counting rate observed when a sampleis replaced by mock sample salts or by reagent chemicals used for chemical separations that contain no analyte.3.2.11.1 DiscussionReagent background varies with the reagent chemicals and analytical me
33、thods used and may vary with reagents from differentmanufacturers and from different processing lots.4. Summary of Test Method4.1 The test sample is reduced by evaporation, transferred to a scintillation vial and mixed with a suitable liquid scintillationcocktail. Gross alpha- and beta- activity con
34、centrations are measured simultaneously by liquid scintillation using alpha/betadiscrimination. By optimizing the alpha/beta discriminator, a high efficiency of alpha- and beta- particle detection can be achievedwith acceptable misclassification of beta particles into the alpha multi-channel analyze
35、r (MCA) and alpha particles into the betaMCA. The alpha- and beta- particle efficiency and spillover calibrations of the liquid scintillation system are determined by usingknown activities of established reference nuclides in test sources having cocktail-solvent ratios comparable to that of the test
36、samples. Some commonly employed reference standards include 241Am, 239Pu, 230Th, natural isotopic abundance uranium(234U, 235U, and 238U), for gross alpha, and 90Sr/90Y, and 137Cs/137mBa for gross beta. Results are reported in activity unitsequivalent along with the reference radionuclide (for examp
37、le, Bq/L gross alpha equiv. 241Am).4.2 If the measurement quality objectives (MQOs) do not require a low detection limit, an aliquant of the sample may be mixeddirectly with a suitable liquid scintillation cocktail for analysis.5. Significance and Use5.1 This test method is intended for the measurem
38、ent of gross alpha- and beta-activity concentrations in the analyses ofenvironmental and drinking waters. For samples submitted to satisfy regulatory or permit requirements, the submitter should assurethat this or any other method used is acceptable to the regulator or permit issuer.5.2 This test me
39、thod is also applicable to the direct analysis of gross alpha- and beta-activity concentrations in water when lowdetection limits are not required. Direct analysis provides a rapid method for determination of gross alpha- and beta-activityconcentrations when low detection limits are not required.5.3
40、 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.5.4 This test method may not be cited as a meth
41、od for the determination of gross alpha- or beta-activity concentrations in asolid/soil matrix or the acid digestate of the same. The use of this test method for such applications brings the potential for seriousbias and incomparability of results dependent on the matrix constituents, manner of samp
42、le preparation or treatment, or both.6. Interferences6.1 The counting efficiencies and spillover for both the alpha and beta components are dependent on the energy of the alpha-or beta-emitter chosen to determine the calibration coefficient. Biases may occur if the energies of the alpha- or beta-par
43、ticleemitting nuclides in the test sample differs significantly from those used to determine the respective counting efficiencies. Bestresults are obtained when the radionuclide composition of the sample is known and the calibration radionuclide is selected to matchas closely as possible the energy
44、of the sample radionuclide.6.2 The use of 137Cs/137mBa as a calibration standard for samples containing radionuclides other than 137Cs may introduce a lowbias in the analytical results unless there is a correction for conversion electron emissions. The conversion electrons from the137mBa progeny are
45、 detected by liquid scintillation yielding greater than 100 % detection efficiency for the 137Cs/137mBa calibrationstandard.6.3 When using uranium as a calibration standard the isotopic abundance of each of the isotopes (234U, 235U, and 238U) mustbe known to accurately determine the standard activit
46、y concentration. Many uranium standards used for mass measurements aredepleted uranium. Natural isotopic abundance uranium and depleted uranium standards contain short-lived decay progeny (234Th,234mPa) which interfere with the spillover calibration unless they are removed immediately prior to calib
47、ration.6.4 Radon is a noble gas, and therefore easily emanates from most matrices. If the radon progeny of the uranium (222Rn),thorium (220Rn), and actinium (219Rn) series emanate from the sample test source prior to counting, radioactive equilibrium isD7283 173disrupted. EPA 900.0 recognizes this d
48、isruption by suggesting a delay of 72 h before the prepared sample is counted for grossalpha. Other published methods such as Standard Methods 7110C provide for a shorter delay of 3 h. Thus the activity of samplescontaining 226Ra will increase significantly with time during the first several weeks a
49、fter preparation. This delay will result inoverestimation of the activity of samples relative to their true 226Ra concentration. This test method advises that any such delayperiod used by the laboratory be based on the measurement quality objectives MQOs inherent in the intended data use (see 11.7).6.5 Radionuclides may be present in the sample in disequilibrium with their parent radionuclides. Many factors, includingdifferential solubility of radionuclides from the matrix in which the parent radionuclide occurs can cause this disequilibrium.Where th
