1、Designation: C 1590 04 (Reapproved 2009)Standard Practice forAlternate Actinide Calibration for Inductively CoupledPlasma-Mass Spectrometry1This standard is issued under the fixed designation C 1590; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, 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 This practice provides guidance for an alternate linearcalibration for the determination
3、of selected actinide isotopesin appropriately prepared aqueous solutions by InductivelyCoupled Plasma-Mass Spectrometry (ICP-MS). This alternatecalibration is mass bias adjusted using thorium-232 (232Th) anduranium-238 (238U) standards. One of the benefits of thisstandard practice is the ability to
4、calibrate for the analysis ofhighly radioactive actinides using calibration standards atmuch lower specific activities. Environmental laboratories mayfind this standard practice useful if facilities are not available tohandle the highly radioactive standards of the individualactinides of interest.1.
5、2 The instrument response for a series of determinationsof known concentration of232Th and238U defines the massversus response relationship. For each standard concentration,the slope of the line defined by232Th and238U is used to derivelinear calibration curves for each mass of interest usinginterfe
6、rence equations. The mass bias corrected calibrationcurves, although generated from interference equations, arespecific to the instrument operating parameters and tuning ineffect at the time of data acquisition. Because interferenceequations are part of the normal ICP-MS manufacturerssoftware packag
7、e, this calibration methodology is widelyapplicable.1.3 For this standard practice, the actinide atomic massrange that has been studied is from amu 232244. Guidance foran extended range of amu 228248 is given in this practice.1.4 Using this practice, analyte concentrations are reportedat each amu an
8、d not by element total (that is,239Pu versusplutonium).1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespon
9、sibility 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:2C 859 Terminology Relating to Nuclear MaterialsC 1168 Practice for Preparation and Dissolutio
10、n of Pluto-nium Materials for AnalysisC 1347 Practice for Preparation and Dissolution of UraniumMaterials for AnalysisC 1411 Practice for The Ion Exchange Separation of Ura-nium and Plutonium Prior to Isotopic AnalysisC 1414 Practice for The Separation of Americium fromPlutonium by Ion ExchangeC 146
11、3 Practices for Dissolving Glass Containing Radioac-tive and Mixed Waste for Chemical and RadiochemicalAnalysisD 1193 Specification for Reagent Water3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to nuclear materials,refer to Terminology C 859.3.1.2 AMUatomic mass unit.4. Summ
12、ary of Practice4.1 Calibration for the actinides by ICP-MS can be per-formed in a variety of ways with varying degrees of dataquality. An alternative calibration method has been developedto compensate for instrument mass bias using a generated massresponse curve defined by the232Th and238U data poin
13、ts. Themass response curve defined by232Th and238U approximatesthe mass response curve from amu 232244 as verifiedexperimentally and graphically depicted in Fig. 1. The massresponse curve shown reflects the operating parameters andtune of the particular instrument in use at the time of datacollectio
14、n. Different tuning parameters or instrumentationcould result in varying degrees of negative, neutral, or positive1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Jun
15、e 1, 2009. Published July 2009. Originally approvedin 2004. Last previous edition approved in 2004 as C 1590 04.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the
16、standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.mass bias. Because the mass response curve defined by232Thand238U used in this standard practice is determined duringeach calibration,
17、 all potential linear variations in mass bias arecompensated for.4.2 The alternative calibration in this standard practicecombines the features of an external linear calibration at eachmass of interest with the mass bias correction of a mass/response curve. The correction for mass bias is integrated
18、 intothe acquisition of the standard data through the use ofinterference equations which, are part of the normal softwarepackage for correction of isobaric interferences in ICP-MSanalyses. Multipoint calibration curves are generated at eachmass of interest, resulting in more accurate quantification
19、thanthat of the typical “semi-quantitative” single point calibrationbased on the mass/response curve alone.4.3 Sample analyses for blanks and samples are performedusing a data acquisition method file without the interferenceequations that were used to derive the calibration curves. Aftercalibration
20、curves are generated, the calibration files are copiedor linked to the analytical acquisition method. The sampleresponses are acquired at each mass, and concentrationscalculated from the mass bias corrected calibration curves.Some ICP-MS vendor supplied control software will permit thelinking of sep
21、arate calibration and acquisition files (that is, youcan choose which calibration files to use to quantitate anyparticular data set regardless of the acquisition file that wasused to acquire the data).4.4 Mixed calibration standard solutions are preparedthrough dilution of single element stock stand
22、ards of thoriumand known abundance uranium (normally depleted in235U)with dilute nitric acid to develop a calibration series coveringthe desired concentration range. Standard concentrations arecalculated for232Th and238U for each calibration solution.4.5 Bismuth-209 (209Bi) is used as an internal st
23、andard andis added in a fixed quantity in all standards and samples tocorrect for both instrument drift and physical sample transportfluctuations.5. Significance and Use5.1 One of the benefits of this standard practice is the abilityto calibrate for the analysis of highly radioactive actinidesusing
24、calibration standards at much lower specific activities(that is,232Th and238U). Environmental laboratories may findthis standard practice useful if facilities are not available tohandle the highly radioactive standards of the individualactinides of interest.5.2 The degree of actual mass bias is vari
25、able and isdependent upon instrument tune parameters. This standardpractice uses universal interference equations to derive a massbias correction that is specific to the instrument parameters andtune used for sample data acquisition and not based on ahistorical average.5.3 Mass bias correction uses
26、the instrument software inter-ference equations and does not require additional subsequentoff-line calculations.5.4 The methodology that this standard practice is based onhas been used for the determination of232Th and237Np inenriched uranium solutions and the determination of241Am inplutonium and u
27、ranium legacy oxides following dissolutionand ion extraction chromatography separation.6. Interferences6.1 Isotopes of different elements forming atomic ions withthe same nominal mass-to-charge ratio (m/z) may causeisobaric interferences in ICP-MS if present in sufficient quan-tity (that is,238U wit
28、h238Pu and241Pu with241Am). Becausethe isotopic abundance of actinides vary widely, it is notpractical to apply an interference correction unless the isotopicabundance of the interference is well characterized. In addition,the hydride of an abundant isotope can interfere with theadjacent higher mass
29、 (that is,238U1Hon239Pu). For thesereasons, it is prudent to implement actinide separation methodsutilizing extraction chromatography resins prior to ICP-MSanalysis to significantly reduce these interferences.36.2 Analyte memory can occur when there are large con-centration differences between stand
30、ards and/or samples thatare analyzed sequentially. Thorium can exhibit memory withinthe sample introduction system. A rinse solution containing0.2M Nitric acid and 0.2M Sulfuric acid has been found to bebeneficial in reducing thorium carryover.7. Apparatus7.1 ICP-MS, computer controlled with associa
31、ted softwareand peripherals.7.2 Autosampler, optional, with tube racks, disposable plas-tic sample tubes.7.3 Variable Micro and Macro Pipettes.8. Reagents8.1 Argon (Ar) Gas, high purity $ 99.99 %.8.2 Deionized Water, high purity, conforming to Specifica-tion D 1193, Type I.3Maxwell, S. L, “Rapid Act
32、inide-Separation Methods,” Journal of AppliedRadioactivity Measurements, Vol 8, No. 4, 1997, pp. 36-44.FIG. 1 Atomic Mass versus Average Normalized ResponseC 1590 04 (2009)28.3 Nitric Acid, (specific gravity 1.42), concentrated nitricacid (HNO3), trace metal grade or better.8.4 Sulfuric Acid, (speci
33、fic gravity 1.84), concentrated sul-furic acid (H2SO4), trace metal grade or better.8.5 Bismuth Stock Solution, (1000 g/mL Bi), matrix nomi-nal 10 % HNO3.8.6 Thorium Stock Solution, (1000 g/mL Th), matrix nomi-nal 2 % HNO3.8.7 Uranium Stock Solution, (1000 g/mL U), matrix nomi-nal 2 % HNO3.8.8 Radio
34、isotope Standards (241Am,242Pu,244Cm, etc.) canbe purchased4to verify calibration curves if laboratory andICP-MS have proper engineering and procedural controls tosafely handle radiological material.9. Hazards9.1 Personnel using this procedure shall be knowledgeableof the safety precautions necessar
35、y for normal chemical,radiological handling protocol and instrumental operation ofICP-MS.9.2 Nitric and sulfuric acids are strong oxidizers, avoidcontact with flammable, powdered, or combustible materials.Avoid contact with skin, eyes and clothing. Do not breathe oringest vapors.9.3 Actinide bearing
36、 materials are radioactive and toxic.Adequate laboratory facilities and ventilation hoods along withsafe handling techniques must be used.Adetailed discussion ofall safety precautions needed is beyond the scope of thisstandard practice. Follow site and facility specific radiationprotection and chemi
37、cal hygiene protocol.10. Procedure10.1 Calibration Standard PreparationBecause the focusof this practice is on mass bias correction and not on anyparticular calibration concentration range or sample matrix,minimal instruction is given for the preparation of calibrationstandards.10.1.1 Mixed Calibrat
38、ion Standard solutions are preparedthrough the quantitative dilution of single element bench stockstandards of thorium and known abundance uranium (normallydepleted in235U) with bismuth as an internal standard innominal 1 % nitric acid or other acid concentration appropriateto match sample matrix.10
39、1.2 Calibration Blank consists of the same acid matrixas the standard solutions with the same concentration bismuthinternal standard.10.1.3 Reagent Blank consists of the same acid and chemi-cal matrix as the samples (if different from the calibrationblank) with the same concentration bismuth intern
40、al standard.Consideration should be given to processing the reagent blankthrough any sample prep evolutions such as digestion or ionextraction chromatography separation.10.2 Sample Preparation:10.2.1 Prior to analysis, digest/dissolve samples as neededusing methods appropriate to the sample matrix s
41、uch asPractices C 1168, C 1347, C 1463, or other laboratory specificprocedures.10.2.2 Use actinide separation procedures when necessaryto reduce matrix and isobaric interferences between overlap-ping isotopes of interest in the digest solutions; such asPractices C 1411 and C 1414, Maxwells “Rapid Ac
42、tinide-Separation Methods,”3or other laboratory specific procedures.10.2.3 Dilute sample into appropriate acid matrix (1 to 2 %HNO3typical) with the same concentration internal standard asin the calibration standards. Dilution of samples should beconsistent with the span of calibration standards.10.
43、3 ICP-MS Instrumental Analysis:10.3.1 Set up the ICP-MS for the analysis using the param-eters given in the manufacturers operating manual. Followingplasma initiation, allow the instrument to reach thermal equi-librium (generally at least 30 min). Optimize the ICP-MS usingroutine tuning protocol for
44、 elemental analysis or tune specific4Isotope Products Laboratories, 3017 N. San Fernando Blvd., Burbank, CA91504; (818) 843-7000.TABLE 1 Universal Interference Equations Used to Perform Calibration Mass Bias CorrectionMass Bias Corrected Calibration Response Calibration Interference EquationCorrecte
45、d (228) = Response (228) 3 0 (238) 3 0.6667 + (232) 3 1.6667Corrected (229) = Response (229) 3 0 (238) 3 0.5 + (232) 3 1.5Corrected (230) = Response (230) 3 0 (238) 3 0.3333 + (232) 3 1.3333Corrected (231) = Response (231) 3 0 (238) 3 0.1667 + (232) 3 1.1667Corrected (232) = Response (232) 3 1Correc
46、ted (233) = Response (233) 3 0 + (238) 3 0.1667 + (232) 3 0.8333Corrected (234) = Response (234) 3 0 + (238) 3 0.3333 + (232) 3 0.6667Corrected (235) = Response (235) 3 0 + (238) 3 0.5 + (232) 3 0.5Corrected (236) = Response (236) 3 0 + (238) 3 0.6667 + (232) 3 0.3333Corrected (237) = Response (237)
47、 3 0 + (238) 3 0.8333 + (232) 3 0.1667Corrected (238) = Response (238) 3 1Corrected (239) = Response (239) 3 0 + (238) 3 1.1667 (232) 3 0.1667Corrected (240) = Response (240) 3 0 + (238) 3 1.3333 (232) 3 0.3333Corrected (241) = Response (241) 3 0 + (238) 3 1.5 (232) 3 0.5Corrected (242) = Response (
48、242) 3 0 + (238) 3 1.6667 (232) 3 0.6667Corrected (243) = Response (243) 3 0 + (238) 3 1.8333 (232) 3 0.8333Corrected (244) = Response (244) 3 0 + (238) 3 2 (232) 3 1Corrected (245) = Response (245) 3 0 + (238) 3 2.1667 (232) 3 1.1667Corrected (246) = Response (246) 3 0 + (238) 3 2.3333 (232) 3 1.33
49、33Corrected (247) = Response (247) 3 0 + (238) 3 2.5 (232) 3 1.5Corrected (248) = Response (248) 3 0 + (238) 3 2.6667 (232) 3 1.6667C 1590 04 (2009)3to the mass range of interest. Limit oxide formation throughinstrument tuning. Oxides are typically monitored using the %ratio of CeO/Ce, usually # 1%.10.4 Actinide Calibration w/Mass Bias Correction:10.4.1 Actinide calibration with mass bias correction isperformed through the use of external linear calibration stan-dards consisting of232Th and238U with209Bi as an internalstandard. Multi-point ca
