1、Designation: C1387 14Standard Guide forthe Determination of Technetium-99 in Soil1This standard is issued under the fixed designation C1387; 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 par
2、entheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide is intended to serve as a reference forlaboratories wishing to perform99Tc analyses in soil. Severaloptions are given for selection of a
3、tracer and for the method ofextracting the Tc from the soil matrix. Separation of Tc fromthe sample matrix is performed using an extraction chroma-tography resin. Options are then given for the determination ofthe99Tc activity in the original sample. It is up to the user todetermine which options ar
4、e appropriate for use, and togenerate acceptance data to support the chosen procedure.1.2 Due to the various extraction methods available, varioustracers used, variable detection methods used, and lack ofcertified reference materials for99Tc in soil, there is insufficientdata to support a single met
5、hod written as a standard method.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user o
6、f this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C859 Terminology Relating to Nuclear MaterialsC998 Practice for Sampling Surface Soil for RadionuclidesC999 Practic
7、e for Soil Sample Preparation for the Determi-nation of RadionuclidesD1193 Specification for Reagent WaterD7168 Test Method for99Tc in Water by Solid Phase Extrac-tion DiskE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 For definitions of terms in this guide, refer
8、to Terminol-ogy C859.4. Summary of Guide4.1 There are no stable isotopes of technetium.Technetium-99 is produced by the fission of uranium andplutonium, and has been released to the environment vianuclear weapons testing and nuclear materials processing. Inan oxidizing environment, it exists as the
9、very mobile pertech-netate ion, TcO4. Technetium-99 is a long-lived (half-life of2.1 E 5 years), weak beta (maximum beta energy of 293 keV)emitting radioisotope.4.2 For the analysis of99Tc in soil, a tracer is added to thesample matrix, or spiked duplicate samples are prepared, andthen the Tc is ext
10、racted from the soil matrix by one of severalmethods, including acid leaching or one of various fusionmethods. The resulting solution is passed through an extractionchromatography column. Technetium is known to be retainedby the extraction chromatography material while most otherelements pass throug
11、h the column. The column is washed withdilute acid to remove any remaining interferents. The resinmay then be counted directly by adding it to a liquid scintil-lation cocktail and counting by liquid scintillationspectrometry, or the Tc may be eluted from the resin foralternative counting or mass spe
12、ctrometric techniques.5. Significance and Use5.1 This guide offers several options for the determinationof99Tc in soil samples. Sample sizes of up to 200 g arepossible, depending on the method chosen to extract Tc fromthe soil matrix. It is up to the user to determine if it isappropriate for the int
13、ended use of the final data.6. Interferences6.1 Any radionuclide not completely removed by the ex-traction chromatography column that has a beta decay energysimilar to or higher than99Tc will interfere when countingtechniques are used for quantification of the99Tc activity.6.2 Any elements with a ma
14、ss-to-charge ratio (m/z) of 99(that is, naturally occurring isotope of99Ru or other artificiallyproduced elements of sufficient half-life with similar m/z) caninterfere when using mass spectrometry for quantification of1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle
15、and is the direct responsibility of Subcommittee C26.05 on Methods of Test.Current edition approved Jan. 1, 2014. Published February 2014. Originallyapproved in 1998. Last previous edition approved in 2008 as C1387 08. DOI:10.1520/C1387-14.2For referenced ASTM standards, visit the ASTM website, www.
16、astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1the99Tc
17、 mass activity. Any element with the same m/z as theisotope used as an isotope dilution tracer or internal standardwill cause a bias in the yield correction. Corrections should beincluded in the mass spectrometry data reduction for knowninterferences.6.3 Additional interferences may be encountered,
18、depend-ing on the tracer and measurement technique chosen. It is up tothe user to determine and correct for any additional interfer-ences.7. Apparatus7.1 Apparatus for the Extraction of Tc from Sample Matrix:7.1.1 See the individual extraction method descriptions tocompile a list of the equipment ne
19、eded for the chosen extrac-tion method.7.2 Apparatus for the Purification of Tc from the SoilExtract:7.2.1 Extraction columnwith a bed volume of severalmilliliters for the extraction chromatography resin.37.2.2 Column extension funnelsthat can be added to theextraction column such that a few hundred
20、 milliliters ofsolution can be added to the column at one time.7.2.3 Column rackholds columns such that several extrac-tions can be performed simultaneously.7.3 Apparatus for the Quantification of99Tc:7.3.1 See the individual detection method descriptions tocompile a list of the equipment needed for
21、 the chosen detectionmethod.8. Reagents8.1 Purity of ReagentsAll chemicals should, at aminimum, be of reagent grade and should conform to thespecifications of the Committee on Analytical Reagents of theAmerican Chemical Society where such specifications areavailable.4High Purity reagents are suggest
22、ed if mass spec-trometry is chosen as the detection method. Other grades ofreagents may be used provided it is first determined that thereagent is of sufficient purity to permit its use without lesseningthe accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referencesto wat
23、er shall be understood to mean reagent water, as definedby Type I of Specification D1193.8.3 Tracer:8.3.1 Isotope Dilution Yield Determination:8.3.1.1 Radiometric Yield Determination95mTc5or99mTc6have been used to monitor the chemical yield of the extractionand purification of99Tc prior to quantific
24、ation. Example: Add10 nCi of99mTc as a yield tracer when determining yield bygamma spectrometry.8.3.1.2 Mass Spectrometric Yield Determination97Tc maybe produced in a nuclear reactor in very limited quantities to beused as an isotope dilution tracer for the mass spectrometricdetermination of99Tc (1)
25、.7Example: Add 1 ng of97Tc as ayield tracer for mass spectrometry.8.3.1.3 Rhenium as a Mass Spectrometric Yield MonitorThe chemical behavior of Re and Tc are similar enough on theextraction resin that Re may be used as a tracer for Tc whenusing ICP-MS as a detection method (2).8.3.2 Duplicate Sample
26、 Analysis to Monitor ChemicalYield:8.3.2.1 Duplicate samples may be analyzed, one spiked witha known amount of99Tc and one unspiked. The chemicalrecovery of the spiked sample is then used to correct theunspiked sample to obtain the original sample activity. (SeeTest Method D7168 for an example of th
27、is method.)8.4 Reagents for the Extraction of99Tc from Sample Matrix:8.4.1 See the individual extraction method descriptions tocompile a list of the reagents needed for the chosen extractionmethod.8.5 Reagents for the Purification of Tc from the SampleMatrix:8.5.1 Extraction Chromatrography ResinTEV
28、A Resin.88.5.2 Prefilter Resina nonionic acrylic ester polymer resinused to remove residual organic matter prior to the extractionchromatography resin column.98.5.3 Hydrogen Peroxide30 %.8.5.4 Nitric Acid(16 M HNO3) concentrated, specificgravity 1.42.8.5.5 1M Nitric AcidAdd 63 mL of concentrated HNO
29、3to900 mL of DI water, dilute to a final volume of 1 liter.8.5.6 4M Nitric AcidAdd 250 mL of concentrated HNO3to 600 mL of DI water, dilute to a final volume of 1 liter.8.6 Reagents for the Quantification of99Tc:8.6.1 See the individual detection method descriptions tocompile a list of the reagents
30、needed for the chosen detectionmethod.9. Procedure9.1 Collect samples in accordance with Specification C998.9.2 Soil or Sediment Preparation:9.2.1 Oven dry samples at a temperature not to exceed105C and homogenize in accordance with Specification C999.9.2.2 OptionalSamples may be placed in a muffle
31、oven todecompose organic matter prior to the extraction of Tc. The3Prepacked columns from Eichrom Technologies, LLC, (Lisle, IL) or BioRad(Richmond, CA) poly prep columns have been found satisfactory for this purpose.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Soci
32、ety, Washington, D. C. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U. K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
33、MD.5 95mTc may be obtained from Analytics, Inc., Atlanta, GA, or other suitablesupplier.6 99mTc may be obtained from a local medical pharmacy supplier or other suitablesupplier.7The boldface numbers in parentheses refer to the list of references at the end ofthis standard.8The sole source of supply
34、of the apparatus known to the committee at this timeis TEVA Resin from Eichrom Technologies, LLC. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical com
35、mittee,1which you may attend.9Prefilter columns are available from Eichrom Technologies, LLC or Amber-chrom GC-71CD resin has been found satisfactory for this purpose.C1387 142muffling techniques reported vary significantly (3-5).Ifdesired, weigh 510 g of the sample and place in a hightemperature cr
36、ucible. Add the chosen yield monitor and mixthe sample. Wet the sample with concentrated ammoniumhydroxide and mix, then dry under a heat lamp. It has beenfound that ammonium hydroxide will prevent the loss of thevolatile Tc at higher temperatures. Place the sample in a muffleoven for 24 hours at 50
37、0C (5), or for 3060 minutes at 600Cfollowed by the addition of a few grams of ammonium nitrateand 10 more minutes of heating if traces of carbon remain (3).9.3 Tc ExtractionThese discussions are summaries fromavailable literature. The user must read the primary referencefor a complete discussion of
38、the method prior to its use.9.3.1 Acid LeachingThere are many reported acid leach-ing techniques in the literature (3, 4, 6-10); however, only thosethat are easily coupled to the extraction chromatographypurification are described in 9.3.1.1 9.3.1.4. These methodsare summarized in the following four
39、 sections9.3.1.1 Weigh out up to 10 grams of soil to a 250 mL glassbeaker along with the desired yield monitor. Cover and heat thesample in the presence of 1M nitric acid.After cooling, removeresidual solid matter from the sample by centrifugation. Addhydrogen peroxide and sodium vanadate to each sa
40、mple todestroy residual organic matter. Finally, reduce the acidity ofthe sample to less than 0.5M using ammonium hydroxide(dilute with water to a final sample volume of approximately500 mL) (6).9.3.1.2 Add the desired yield monitor to 510 g of sample,which is then ashed using step 9.2.2. Leach the
41、sample twicewith hot 8M nitric acid and hydrogen peroxide, combining theleachates. Adjust the pH to 7 with sodium hydroxide and filterthe solution through a glass fiber filter. Dilute the filtrate toapproximately 500 mL (7).9.3.1.3 Weigh out up to 200 grams of sample. Add thedesired yield monitor.As
42、h using step 9.2.2. Transfer the sampleto a decomposition vessel. Add 6M nitric acid. Decompose thesample at 100120C for one hour. Filter the sample through aglass fiber filter then dilute with water until the acid concen-tration is less than 0.5M nitric acid (at least 500 mL) (8).9.3.1.4 Weigh out
43、one gram of the dried, unashed sample toa 250 mL conical flask. Add the desired yield monitor. Addconcentrated nitric acid and fit into a reflux condenser. Refluxthe sample until the brown fumes cease and all the organicmatter is dissolved. Cool the flask and pour the solution intowater. Neutralize
44、the solution with sodium hydroxide, filter outany undissolved residue, and dilute with water until the acidconcentration is less than 0.5M nitric acid and to a final volumeof 250500 mL (9).9.3.2 Soil FusionThe following two methods have beenused for Tc-99.9.3.2.1 Weigh out four grams of sample. Add
45、the desiredyield monitor and ash using step 9.2.2. When cool, transfer thesample to a nickel crucible. Add 20 gram of the flux mixture(Na2CO3,K2CO3and NaNO3in a 3.92:5.08:1.00 weight ratio;the flux-to-sample ratio should be 5:1). Start the fusion byheating the crucible with the sample over a burner
46、at high heat.When no further reaction is visible, cover the crucible andplace in a muffle over set at 900C for 30 minutes. Remove thesample from the oven and cool. Cover the crucible with awatch glass and add about 25 mL of water to the crucible tostart dissolving the cake. Transfer the solution to
47、a beaker andcontinue rinsing the crucible with water until all the cake isrinsed into the beaker. Cover the beaker and warm slightly ifneeded to complete the dissolution. Dilute with water to a finalvolume of about 200250 mL (11).9.3.2.2 It is suggested that the sample be ground to passthrough a 45
48、micron standard test sieve as defined in Specifi-cation E11. This will result in a homogeneous sample with aparticle size that can be attacked by the fusion procedure.Weigh out 0.25 gram of sample to a zirconium crucible. Addthe desired yield monitor. Add 2.25 gram of sodium peroxideand mix well. Pl
49、ace the crucible in a muffle oven preheated to470C. Heat for 30 minutes. Remove from the oven. Whencool, add about 40 mL of water. Allow the mixture to dissolvefor approximately one hour. Add 4 mL of concentrated nitricacid to the crucible and dilute the solution to a final volume ofapproximately 150200 mL with water such that the final acidsolution is less than 0.5 M (12).9.3.3 Microwave DigestionThe following two methodshave been used for99Tc.9.3.3.1 Weigh out 0.5 gram of sample into a microwavedigestion vessel. Add the desired yield monitor
