1、Designation: D8026 16Standard Practice forDetermination of Tc-99 in Water by Inductively CoupledPlasma Mass Spectrometry (ICP-MS)1This standard is issued under the fixed designation D8026; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year 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 Technetium is separated and concentrated from a watersample by extraction chromatography using its c
3、hemicalanalog, rhenium, as a tracer. The ratio of technetium to rheniumis measured by inductively coupled plasma mass spectrometry(ICP-MS) to then quantify the99Tc concentration.1.1.1 This practice is provided as an alternative to TestMethod D7168 which provides for a different separation mediageome
4、try and measurement by liquid scintillation spectrom-etry. Similar detection limits should be attainable by thismethod.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thes
5、afety concerns, if any, associated with its use. It is theresponsibility of the user of 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:2C1387 Guide for the Determina
6、tion of Technetium-99 inSoilD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water A
7、nalysisD7168 Test Method for99Tc in Water by Solid Phase Extrac-tion DiskD7902 Terminology for Radiochemical Analyses3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminologies D1129 and D7902.4. Summary of Practice4.1 A known quantity of Re is added to
8、a known volume ofa filtered water sample. The sample is heated in the presence ofperoxide to ensure the Tc and Re are in the oxidized form. TheTc and Re are then extracted from the sample using anextraction chromatography resin loaded in a column.3, 4Theresin is rinsed of some co-retained elements a
9、nd then the Tcand Re are co-eluted from the resin.4.2 An ICP-MS is used to determine the ratio of Tc relativeto the Re tracer; the Re is used as an internal standard tomonitor instrument response as well as to correct for chemicalyield of the Tc through the column separation.5. Significance and Use5
10、.1 Technetium-99 is produced by the fission of uraniumand plutonium, and has been released to the environment vianuclear weapons testing and nuclear materials processing. Inan oxidizing environment, it exists as the very mobile pertech-netate ion, TcO4, which is an analog to nitrate and can betaken
11、up by living organisms. Monitoring of99Tc in watersaround nuclear processing facilities is part of a completeenvironmental monitoring program.5.2 Technetium-99 is a long-lived (half-life 2.1E+5years),weak beta (maximum beta energy of 293 keV) emittingradioisotope. There are no stable isotopes of Tc.
12、 Thus thedetermination of its activity concentration presents uniquechallenges to traditional radiochemical determination methods.This method provides an alternative to the spiked/unspikedreplicate method of Method D7168 and uses options presentedin Guide C1387 for the determination of99Tc in soil.1
13、This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.04 on Methods of RadiochemicalAnalysis.Current edition approved Feb. 15, 2016. Published March 2016. DOI: 10.1520/D8026-16.2For referenced ASTM standards, visit the ASTM website
14、, www.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.3Tagami, K., and Uchida, S., Analytica Chimica Acta, Vol 405, 2000, pp.227229.4Kabai, E., Beyermann, M., Seeger, J.
15、, Savkin, B. T., Stanglmaier, S., andHiersche, L., Applied Radiation and Isotopes, Vol 81, 2013, pp. 641.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Interferences6.1 Any element with a mass-to-charge ratio (m/z) of 99(that is,
16、naturally occurring isotope of99Ru, or other artificiallyproduced elements of sufficient half-life with similar m/z) caninterfere when using mass spectrometry for quantification ofthe99Tc activity. Any element with the same m/z as the isotopeused as an isotope dilution tracer or internal standard, t
17、hat is,m/z of 185 or 187, will cause a bias in the yield correction.Corrections should be included in the mass spectrometry datareduction for known interferences.6.2 High levels of nitrate in the sample could lead tosaturating the active sites on the resin and cause low recoveryof the Tc and Re. The
18、y should be equally affected by this andtherefore observed as a low signal for the Re in the ICP-MSanalysis.6.3 Most other elements will not be retained by the extrac-tion resin at the low acidity suggested in this practice. The usershould determine if any elements exist at high enough concen-tratio
19、n to affect the retention of the Tc and Re, and if they causea bias in the effective retention of the two elements of interest.7. Apparatus7.1 Extraction column, a standard geometry column to hold2 mL of resin and allow connection to an extension funnel.7.2 Column extension funnels, that can be adde
20、d to theextraction column such that a few hundred mL of solution canbe added to the column at one time.7.3 Column rack, holds columns such that several extrac-tions can be performed simultaneously.7.4 Vacuum pump, vacuum box, or other vacuum filtrationapparatus (optional)to facilitate the flow throu
21、gh the col-umn.7.5 Inductively CoupledPlasma Mass Spectrometer, withall associated hardware and software for sample analysis.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 theA
22、merican Chemical Society where such specifications areavailable.5High Purity reagents are suggested when massspectrometry is the detection method.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water, as definedby Type III of Specification D1193.
23、8.3 Extraction chromatography resin, an aliphatic quater-nary amine which is mainly used for Tc analysis as well as forthe separation of tetravalent actinides.6, 7NOTE 1If using the purchased prepared resin, the large particle sizeshould be used; back extraction from the small particle resin may not
24、 beequivalent for the Tc and the Re.8.4 Prefilter Resin, anonionic acrylic ester polymer resinused to remove residual organic matter prior to the extractionchromatography resin column.8.5 Hydrogen Peroxide, 30 %.8.6 Nitric Acid (16M HNO3), concentrated, specific gravity1.42, high purity.8.7 1M Nitri
25、c AcidAdd 63 mL of HNO3(8.6) to 900 mLof water, dilute to a final volume of 1 L.8.8 8M Nitric AcidAdd 500 mL of HNO3(8.6) to 400 mLof water, dilute to a final volume of 1 L.8.9 Rhenium tracer solution, commercially available as amass spectrometry solution standard, diluted to a knownvolume to provid
26、e the desired mass to the test sample in aconvenient delivery volume.8.10 Technetium-99 standard solution, traceable solution,diluted to a useful activity concentration, for method validationand instrument calibration. Available from commercial suppli-ers of radioactive materials.9. Hazards9.1 Use e
27、xtreme caution when handling all acids. They areextremely corrosive, and skin contact could result in severeburns.9.2 When diluting concentrated acids, always use safetyglasses and protective clothing, and add the acid to the water.10. Procedure10.1 The following steps are provided as guidance forpe
28、rforming this Practice. The laboratory should define finitevalues when performing method validation and sample testing.10.1.1 Collect a water sample according to prescribedmethods. The sample should be analyzed within a few days ofcollection or preserved by refrigeration at less than 6C, but notfree
29、zing, until analysis. The sample should be filtered prior toanalysis to remove debris that could adversely impact thecolumn flow.10.1.2 Transfer a known volume of water, up to 1 L, to alarge glass beaker. Add a known amount of Re as the tracer,nominally 10 ng, to the beaker. Add 10 mL of hydrogenper
30、oxide and heat the sample to 80C with stirring for a few5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd
31、., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.6The sole source in the United States of the Eichrom TEVA resin known to thecommittee at this time is Eichrom Technologies, LLC, in Lisle, IL, 60532, and it canb
32、e purchased from the appropriate vender based on international location. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee, which you may a
33、ttend.7See also Horwitz, P., Dietz, M., Chiarizia, R., Diamond, H., “Separation andpreconcentration of actinides by extraction chromatography using a supported liquidanion exchanger: application to the characterization of high-level nuclear wastesolutions,” Anal. Chim. Acta, Vol 310, 1995, pp. 6378.
34、D8026 162hours to break down organic matter. Let the sample cool toroom temperature prior to the column extraction.10.1.3 Place a column in the column rack for each sample tobe analyzed. Prefilled extraction chromatography columns areavailable or add about 2 mL of extraction resin to a standardcolum
35、n geometry. For samples containing residual dissolvedorganic matter, it is recommended to place a prefilter resincolumn in series prior to the extraction chromatographycolumn.10.1.4 Condition each extraction column by adding 5 mL of0.1M nitric acid to each column, and allow the column to drain.10.1.
36、5 Add a column extension funnel to each column andthen pour the prepared sample through the columns. Techne-tium and rhenium will be retained by the extraction chroma-tography resin at volumes up to 1 L as long as the acidity of thesolution is less than 0.5M HNO3. Rinse the sample containerwith a fe
37、w mL of water and add to the column reservoir.NOTE 2A vacuum box or similar apparatus may be used to pull thesolution through the column but flow rates should not exceed 5 mL perminute.10.1.6 Allow the entire sample to pass through the column.If a prefilter column was used it should be removed anddi
38、scarded in accordance with applicable regulations. Rinse theextraction column with 2550 mL of 1M nitric acid, undergravity flow rate, or up to 2 mL per minute. This will removeMo and Ru which are similar in mass to Tc thereby providinga more stable baseline in the Tc mass analysis region.10.1.7 Plac
39、e a clean container under the column and elutethe Tc and Re with 30 mL of8MHNO3.10.1.8 Reduce the solution volume to near dryness usinglow heat (100120C). Reconstitute the sample in 20 mL of2% nitric acid. (WarningDo not heat the sample to completedryness as this may result in the volatilization and
40、 loss of theTc.)11. Analysis by Inductively Coupled Plasma MassSpectrometry11.1 Refer to the instrument operating manual or otherlaboratory-specific procedures for setup and calibration proce-dures for the instrument.11.1.1 Typically a calibration curve will be generated by theanalysis of calibratio
41、n solutions with known and varyingamounts of Tc and a constant amount of Re, which ismonitored as the internal standard.11.1.2 Blank correction should not be performed automati-cally by the instrument.11.2 Program the instrument to monitor the desired massesand perform the appropriate isotopic abund
42、ance corrections.11.2.1 For example, monitor m/z of 99, 101, 185 and 187;m/z 101 is monitored to make corrections to the99Tc for anyruthenium interference; 185 and 187 are monitored as theinternal standard to correct for chemical yield, matrix suppres-sion of the sample on the plasma ionizing proper
43、ties, and anyinstrument drift in sensitivity.11.3 Program the instrument to perform the analysis interms of dwell time, number of passes, number of analyses persample, etc.11.4 When the instrument is programmed to monitor Re asthe internal standard it can be programmed to report the Tcconcentration
44、in each sample analyzed. When converting theTc concentration to activity units ensure reference is made tothe source used for the half-life of99Tc.12. Quality Control12.1 The following recommendations are based on therequirements of Practice D5847.12.2 Initial Demonstration of Laboratory Capability:
45、12.2.1 If the laboratory or analyst has not previously per-formed this method, a precision and bias study must beperformed to demonstrate laboratory capability.12.2.2 Analyze seven replicates of a standard solutionprepared from an independent reference material containing99Tc spiked at a concentrati
46、on in the mid-range of the calibra-tion curve. The matrix used for the demonstration shouldrepresent a water sample typical for which the method will beused, (for example, surface water). The total dissolved solids ofthe matrix should approximate the levels expected in normaluse.12.2.3 Calculate the
47、 mean and standard deviation of theseven values. The study should be repeated until precision andbias meet desired limits.12.2.4 Analyze three replicates of a blank solution matrix.The matrix used for the demonstration should represent a watersample typical for which the method will be used (for exa
48、mple,surface water). The total dissolved solids of the matrix shouldapproximate that which may be encountered in normal use.12.2.5 Calculate the99Tc activity for each of these threeblank solutions. The study should be repeated until the99Tcresult of each of the three blank solutions is below one-hal
49、f theassociated MDC.12.3 Laboratory Control Sample (LCS):12.3.1 To ensure that the test method is in control, analyzean LCS with each batch of no more than 20 samples. Theactivity added to reagent water should be appropriate for thetype of samples analyzed and should produce results ofsufficient precision to ensure meaningful assessment of accu-racy. The LCS must be taken through all the steps of theanalytical method including sample preservation and pretreat-ment.12.3.2 The result obtained for the LCS shall fall within thelimit of 25 % of the expected value, or
