1、Designation: D3454 11D3454 18Standard Test Method forRadium-226 in Water 1This standard is issued under the fixed designation D3454; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses
2、 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 soluble, suspended, and total 226radium-226Ra in water in concentrations above3.7 103 Bq/L. This test method is n
3、ot applicable to the measurement of other radium isotopes.1.2 This test method may be used for quantitative measurements by calibrating with a 226radium-226Ra standard, or for relativemeasurements by comparing the measurements made with each other.1.3 This test method does not meet the current requi
4、rements of Practice D2777.1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units values given in parentheses are forinformation only.mathematical conversions to inch-pound units that are provided for information only and are not consideredstandard.1.5 Hydrofluoric
5、 acid (HF) is very hazardous and should be used in a well-ventilated hood. Wear rubber gloves, safety glassesor goggles, and a laboratory coat. Avoid breathing any HF fumes. Clean up all spills promptly and wash thoroughly after usingHF.1.6 This standard does not purport to address all of the safety
6、 concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.7 This international standard was developed in ac
7、cordance with internationally 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
8、 Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3648 Practices for the Measurement of RadioactivityD3
9、649 Practice for High-Resolution Gamma-Ray Spectrometry of WaterD3856 Guide for Management Systems in Laboratories Engaged in Analysis of WaterD4448 Guide for Sampling Ground-Water Monitoring WellsD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water AnalysisD
10、6001D7902 Guide for Direct-Push Groundwater Sampling for Environmental Site CharacterizationTerminology for Radio-chemical AnalysesD7282 Practice for Set-up, Calibration, and Quality Control of Instruments Used for Radioactivity Measurements3. Terminology3.1 For definitions of terms used in this tes
11、t method, refer to Terminology D1129. For terms not defined in this test method orin Terminology D1129, reference may be made to other published glossaries.Definitions:1 This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.04
12、on Methods of RadiochemicalAnalysis.Current edition approved June 15, 2011. Published July 2011. Originally approved in 1975. Last previous edition approved in 2005 as D3454 05. DOI: 10.1520/D3454-11.Current edition approved Oct. 1, 2018. Published November 2018. Originally approved in 1975. Last pr
13、evious edition approved in 2011 as D3454 11. DOI:10.1520/D3454-18.2 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 the ASTM web
14、site.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 consult prio
15、r 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 States13.1.1 For definitions of terms used in this
16、 standard, refer to Terminologies D1129 and D7902.4. Summary of Test Method4.1 This test method3 is based on the emanation and scintillation counting of 222Rn, a gaseous daughterprogeny productof 226Ra, from a solution.4.2 226Ra is collected from water by coprecipitation on a relatively large amount
17、 of barium sulfate. The barium-radium sulfateis decomposed by fuming with phosphoric acid, and the resulting glassy melt is dissolved by evaporation with dilute hydrochloricacid to form soluble barium-radium phosphates and chlorides. These salts are dissolved and the solution is stored for ingrowth
18、of222Rn. After a suitable ingrowth period, the radon gas is removed from the solution by purging with gas and transferred to ascintillation counting chamber. About 4 h after 222Rn collection, the scintillation chamber is counted for alpha activity. The 226Raconcentration is calculated from the alpha
19、 count rate of 222Rn and its immediate daughters.progeny. The radioactive decaycharacteristics of 226Ra and its immediate decay progeny are listed in Table 1.5. Significance and Use5.1 The most prevalent of the five radium isotopes in ground water, having a half life greater than one day, are 226Ra
20、and 228Ra.These two isotopes also present the greatest health risk compared to the other naturally occurring nuclides of equal concentrationsif ingested via the water pathway.5.2 Although primarily utilized on a water medium, this technique may be applicable for the measurement of the 226Ra contento
21、f any media once the medium has been completely decomposed and put into an aqueous solution.5.3 The general methodology and basis of this technique are similar to the methodology “Radium-226226Ra in Drinking Water(Radon Emanation Technique)” as described in the document EPA-600/4-80-032.46. Interfer
22、ences6.1 Only the gaseous alpha-emitting radionuclides interfere, namely, 219Rn and 220Rn. Their half lives are 3.9 s and 54.5 s,respectively; their presence indicates the presence of their parents, 223Ra and 224Ra. These short-lived radon isotopes decay beforethe 222Rn is counted; it is their alpha
23、-emitting decay products that would interfere. These interferences are very rare in watersamples but are frequently observed in certain uranium mill effluents.7. Apparatus7.1 Radon Bubbler (Fig. 1).7.2 Radon Scintillation Chamber (also known as Lucas Cell) (Fig. 2).3 This test method is based on a p
24、reviously published method by Rushing, D.E., Garcia, W.J., and Clark, D.A. “TheAnalysis of Effluents and Environmental Samples fromUranium Mills and of Biological Samples for Radium, Polonium and Uranium,” Radiological Health and Safety in Mining and Milling of Nuclear Materials, Vol. II, IAEA,Vienn
25、a, Austria, 1964), p. 187.This test method is based on a previously published method by Rushing, D. E., Garcia, W. J., and Clark, D. A., “The Analysis of Effluentsand Environmental Samples from Uranium Mills and of Biological Samples for Radium, Polonium and Uranium,” Radiological Health and Safety
26、in Mining and Millingof Nuclear Materials, Vol II, IAEA, Vienna, Austria, 1964, p. 187.4 “Radium-226 in Drinking Water (Radon Emanation Technique),” Prescribed Procedures for Measurement of Radioactivity in Drinking Water, August 1980.TABLE 1 Radioactive Decay Characteristics of 226Radium-226 Raand
27、Its Daughters ProgenyNOTE 1Monographie BIPM-5 Table of Radionuclides, Commentson Evaluations, Vols 1-8, Bureau International des Poids et Mesures,2016, available from http:/www.nucleide.org.Radionuclide Half-life Half-Life Mode of Decay226Ra 1600 years 222Rn 3.82 days 222Rn 3.8232 days 218Po 3.10 mi
28、n 218Po 3.071 min 214Pb 26.8 min , 214Pb 26.916 min , 214Bi 19.9 min , 214Bi 19.8 min , 214Po 164/3 s 214Po 162.3 s 210Pb 22.2 years , 210Pb 22.23 years , D3454 1827.3 Manometer, open-end capillary tube or vacuum gage having a volume which is small compared to the volume of thescintillation chamber,
29、 0 760 mm Hg (Fig. 3).7.4 Gas Purification Tube, 7 to 8 mm 8-mm outside diameter standard wall glass tubing, 100 mm long, constricted at lower endto hold a glass wool plug (Fig. 3). The upper half of the tube is filled with magnesium perchlorate and the lower half with a sodiumhydrate-asbestos hydro
30、xide-coated silica absorbent.7.5 Scintillation Counter Assembly, consisting of a 50 mm (2 in.) or more in diameter photomultiplier tube mounted in alight-tight housing and coupled to the appropriate preamplifier, high-voltage supply, and scaler.Ahigh-voltage safety switch shouldopen automatically wh
31、en the light cover is removed to avoid damage to the photomultiplier tube. The preamplifier shouldincorporate a variable gain adjustment. The counter should be equipped with a flexible ground wire which is attached to the chassisphotomultiplier tube by means of an alligator clip or similar device. T
32、he operating voltage is ascertained by determining a plateauusing 222Rn in the scintillation chamber as the alpha source. The slope of the plateau should not exceed 2 %100 V. The counterand the scintillation chamber should be calibrated and used as a unit when more than one counter is available. The
33、 backgroundcounting rate for the counter assembly without the scintillation chamber should range from 0.00 to 0.0005 s1.7.6 Membrane Filters, 0.45 m 0.45-m pore size.7.7 Silicone Grease, high-vacuum, for bubbler stopcocks.7.8 Platinum Ware, crucibles, 20 to 30 mL, and one 500 mL 500-mL capacity dish
34、. Platinum ware is cleaned by immersing androtating in a molten bath of potassium pyrosulfate, removing, cooling, and rinsing in hot tap water, digesting in hot 6M6M HCl,hydrochloric acid (HCl), rinsing in water, and finally flaming over a burner.7.9 Laboratory GlasswareGlassware may be decontaminat
35、ed before and between uses by heating for 1 h in EDTA-Na2CO3decontaminating solution at 90 to 100C, then rinsing in water, in 1M1M HCl and again in water.FIG. 1 Radon BubblerD3454 1838. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise i
36、ndicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society.5 Othergrades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lesseningthe ac
37、curacy of the determination.8.2 Purity of WaterUnless otherwise indicated, reference to water shall be understood to mean conforming to SpecificationD1193, Type III.8.3 Radioactive Purity of ReagentsRadioactive purity shall be such that the measured results of blank samples do not exceedthe calculat
38、ed probable error of the measurement or are within the desired precision.8.4 Ammonium Sulfate Solution (100 g/L)Dissolve 10 g of ammonium sulfate (NH4)2SO4) in water and dilute to 100 mL.8.5 Barium Chloride Carrier Solution Stock, (17.8 g/L)Dissolve 17.8 g of barium chloride (BaCl22H2O) in water and
39、 diluteto 1 L. This solution will contain 10 mg/mL Ba+ +.8.6 Barium-133 Tracer Solution(approximately 3 kBq/mL).8.7 Barium Chloride Carrier Solution, WorkingAdd 100 mL of barium chloride carrier stock solution and 10 mL of133barium-133Ba tracer solution to 890 mL of water and mix thoroughly. This so
40、lution will contain approximately 1 g/L of Ba +. Allow to stand for 24 h and filter through a membrane filter.5 The sole source of supply of the radon bubbler known to the committee at this time is Corning Glass Works, Special Sales Section, Corning, N.Y. 11830. If you are awareof alternative suppli
41、ers, please provide this information toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee.5 “ReagentReagent Chemicals, American Chemical Society Specifications,”Specifications, Am.American Chemical Soc.,Society, Washing
42、ton, DC. For suggestions on thetesting of reagents not listed by the American Chemical Society, see “AnalarAnalar Standards for Laboratory Chemicals,”Chemicals, BDH Ltd., Poole, Dorset, U.K., andthe “UnitedUnited States Pharmacopeia,”Pharmacopeia and National Formulary, U.S. PharmaceuticalPharmacope
43、ial Convention, Inc. (USPC), Rockville, MD.FIG. 2 Radon Scintillation ChamberD3454 1848.8 EDTA-Sodium Carbonate Decontaminating SolutionDissolve 10 g of disodium ethylenediaminetetraacetate and 10 g ofsodium carbonate (Na2CO3) in water and dilute to 1 L.8.9 FluxTo a large platinum dish (about 500-mL
44、 capacity) add 30 mg of BaSO4, 65.8 g of K2CO3, 50.5 g of Na2CO3, and33.7 g of Na2B4O710 H2O. Mix well and heat cautiously until the water is expelled; fuse and mix thoroughly by swirling. Coolflux, grind it in a porcelain mortar to pass a U. S. U.S. Standard No. 10 (2.00-mm) (or finer) sieve. Store
45、 in an airtight bottle. (Fluxcan be prepared in smaller batches.)8.10 Hydrochloric Acid (sp gr 1.19)Concentrated hydrochloric acid (HCl).HCl.8.11 Hydrochloric Acid Solution 6M (1 + 1)Mix 1 volume of concentrated HCl (sp gr 1.19) with 1 volume of water.8.12 Hydrochloric Acid Solution 1M (1 + 11)Mix 1
46、 volume of concentrated HCl (sp gr 1.19) with 11 volumes of water.8.13 Hydrochloric Acid Solution 0.24M (1 + 49)Mix 1 volume of concentrated HCl (sp gr 1.19) with 49 volumes of water.8.14 Hydrochloric Acid Solution 0.1M (1 + 119)Mix 1 volume of concentrated HCl (sp gr 1.19) with 119 volumes of water
47、.8.15 Hydrofluoric Acid (sp gr 1.15)Concentrated hydrofluoric acid (HF). HF. Use extreme caution.8.16 Hydrogen Peroxide 3 % (1 + 9)Mix 1 volume of Hhydrogen peroxide (H2O2 (30 %) (30 %) with 9 volumes of water.8.17 Magnesium PerchlorateAnhydrous magnesium perchlorate Mg(ClO(Mg(ClO4)2.).8.18 Phosphor
48、ic Acid (sp gr 1.69)Concentrated phosphoric acid (H3PO4).8.19 Radium Standard Solution (0.37 Bq/mL).,FIG. 3 De-emanationDe-Emanation AssemblyD3454 1858.20 Sodium Hydroxide-Coated SilicateSilica Absorbent, Proprietary,6,8 to 20 mesh.8.21 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid (H2SO4).8.
49、22 Sulfuric Acid Solution 0.05M (1 + 359)Mix 1 volume of concentrated H2SO4 (sp gr 1.84) with 359 volumes of water.This solution is 0.1 N. Slowly add acid to water.8.23 Helium, in a high-pressure cylinder with a two-stage pressure regulator and needle valve.9. Sampling9.1 Collect the sample in accordance with the applicable standards as described in Practices D3370.10. Calibration and Standardization10.1 Close the inlet stopcock of a bubbler,bubbler (Note 1), add 5 mL of BaCl22H2O carrier solution, 1 mL of
