1、Designation: D5153 10Standard Test Method forPalladium in Molecular Sieve Catalyst by AtomicAbsorption1This standard is issued under the fixed designation D5153; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. 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 determination of palladiumin molecular sieve-containing fresh catalysts with about 0.5weight % of p
3、alladium.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 thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to estab
4、lish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to
5、Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodD7442 Practice for Sample Preparation of Fluid CatalyticCracking Catalysts and Zeolites for Elemental Analysis byInductively Coupled Plasma Atomic Emission Spectros-copy2.2 U.S. Fede
6、ral Specification:Federal Spec. NNN-P-395C Tolerance for Class A Pipets33. Summary of Test Method3.1 The test sample is treated with a mixture of sulfuric andhydrofluoric acids. Upon dissolution, the excess hydrofluoricacid is expelled. Aqua regia and lanthanum chloride are addedand the solution is
7、diluted to a specific volume. Palladiumconcentration is determined by atomic absorption spectropho-tometry. Absorbance of the samples is bracketed using a set ofnarrow range, matrix matched standards. A second sample,taken at the same time as the analysis sample, is used todetermine loss on ignition
8、.4. Significance and Use4.1 This test method provides a means of determining thepalladium content in fresh catalysts containing molecularsieves.4.2 This test method is not intended to cover samplescontaining precious metals other than palladium.5. Apparatus5.1 Analytical Balance, capable of weighing
9、 to nearest0.1 mg.5.2 Atomic Absorption Spectrophotometer.5.3 Beakers, TFE-fluorocarbon, 100-mL.5.4 Crucibles, porcelain, 10-mL.5.5 Crucible Cover, porcelain, for 10-mL crucible.5.6 Desiccator.5.7 Flasks, Erlenmeyer, 2000-mL.5.8 Graduated Cylinders, glass, 5-mL, 10-mL, 25-mL,50-mL, 250-mL, 500-mL, 1
10、000-mL.5.9 Graduated Cylinder, plastic, 10-mL.5.10 Hot Plate.5.11 Muffle Furnace, electrically heated, capable of 1000C.5.12 Pipets, 4-mL, 6-mL, 8-mL, 10-mL.5.13 Volumetric Flasks, 100-mL, 500-mL.5.14 Watch Glasses, TFE-fluorocarbon, for 100-mL beaker.5.15 Weighing Papers.1This test method is under
11、the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.03 on ChemicalComposition.Current edition approved Nov. 1, 2010. Published January 2011. Originallyapproved in 1991. Last previous edition approved in 2004 as D515304. DOI:10.1520/D5153-10.2For re
12、ferenced 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 standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg.
13、4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated,
14、it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused provided it is first ascertained that the reagent is ofsufficiently high purity to permit its
15、 use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Specification D1193.6.3 Hydrochloric Acid, concentrated, 36.538.0 wt. % or 12M, sp gr 1.18.6.4 Hydrofluoric Acid, concentra
16、ted, 48.051.0 wt. % or28.9 M, sp gr 1.17.NOTE 1Refer to Section 8 of Practice D7442-08 for hazards associ-ated with handling of acids.6.5 Nitric Acid, concentrated, 69.071.0 wt. % or 15.7 M, spgr 1.41.6.6 Sulfuric Acid, concentrated, 95.098.0 wt. % or 18 M,sp gr 1.84.6.7 Aluminum Oxide (Al2O3).6.8 L
17、anthanum Chloride (LaCl37H2O).6.9 Palladium Wire, 99.99 %.6.10 Aqua RegiaMix three parts by volume of concen-trated hydrochloric acid (12 M) and one part by volume ofconcentrated nitric acid (15.7 M) immediately before use.6.11 Sulfuric Acid, 15.816.3 wt. % or 3M. Cautiously add250 mL of concentrate
18、d sulfuric acid (18 M) to 1250 mL ofwatermix well and allow to cool.6.12 Palladium Standard Solution, 500 mg/L. Dissolve0.2500 6 0.0001 g of palladium wire (99.99 %) in 25 mL ofaqua regia. Evaporate the solution to dryness on a steam bath.Dissolve the remaining salts by addition of 25 mL of concen-t
19、rated hydrochloric acid (12 M) and 25 mL of distilled water.Transfer the solution to a 500 mL volumetric flask and dilute tovolume when cool.NOTE 2A commercially available atomic absorption palladium refer-ence solution may be used if it is known to be reliable.6.13 Lanthanum Chloride SolutionDissol
20、ve 25.5 g oflanthanum chloride (LaCl37H2O) in distilled water, dilute to100 mL and mix well. This solution serves as an ionizationsuppressor in atomic absorption.6.14 Desiccant, molecular sieve, type 4A.7. Procedure7.1 Preparation of Calibration Standards:7.1.1 If the concentration of aluminum oxide
21、 in the sampleis unknown, digest a representative sample in acid and deter-mine the aluminum concentration by atomic absorption spec-trophotometry.7.1.2 Transfer 30 mL of sulfuric acid (3M) to five TFE-fluorocarbon beakers.7.1.3 To each beaker add the equivalent weight of aluminumoxide that would be
22、 present in 0.8000 g of sample asdetermined in 7.1.1.NOTE 3If it is available, 0.800 g of catalyst base material may besubstituted for the aluminum oxide.7.1.4 Transfer 0, 4, 6, 8 and 10 mL of the 500 mg/Lpalladium standard to the five TFE-fluorocarbon beakers.7.1.5 Add 10 mL of concentrated hydrofl
23、uoric acid to eachbeaker.7.1.6 Cover the beakers with TFE-fluorocarbon lids anddigest on a hot plate at medium heat until all solid material isin solution (including any brown stains that may appear on thebeaker walls) and light fumes are evolved.NOTE 4If brown stains do not redissolve, discard samp
24、le and prepareagain.7.1.7 Cool the solutions. Dilute to 70 mL with distilledwater. Add 10 mL of aqua regia. Boil gently for a few minuteson a hot plate.7.1.8 When the solution is cool, transfer quantitatively to a500-mL volumetric flask.7.1.9 Add 5 mL of the lanthanum chloride solution to eachflask.
25、 Dilute to volume when the solution has reached roomtemperature.7.1.10 The concentration of palladium will be 0, 4, 6, 8 and10 mg/L.NOTE 5The standard solutions are stable for two months.7.2 WeighingPrepare a carefully riffled, finely groundsample of ambient-equilibrated catalyst. For example, thesa
26、mple could be thinly spread on filter paper and exposed toroom conditions for 16 h. The test method requires 7 to 10 g ofsample. Samples for LOI and analysis shall be weighed at thesame time.7.2.1 For determination of percent loss on ignition at1000C, ignite a porcelain crucible with lid at 1000C fo
27、r atleast 30 min, place in desiccator to cool and weigh to nearest0.1 mg. Transfer approximately 2.0 g of ambient-equilibratedsample to the crucible and weigh to the nearest 0.1 mg with thelid in place. Duplicate loss on ignition measurements arerequired to determine the average LOI noted in the fin
28、alcalculations.7.2.2 For determination of palladium, transfer in triplicate0.75 to 0.85 g of sample, weighed to the nearest 0.1 mg, intoa 100-mL TFE-fluorocarbon beaker.7.3 Loss on Ignition:7.3.1 Place the porcelain crucible containing the test samplein a muffle furnace maintained at 450C and heat f
29、or at least 30min.7.3.2 Transfer the crucible to a muffle furnace maintained at1000C and heat for 1.5 h to constant weight.7.3.3 Remove the crucible from the furnace, place in des-iccator to cool, and weigh to nearest 0.1 mg.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemi
30、cal Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockv
31、ille,MD.D5153 1027.3.4 Calculate weight percent loss on ignition at 1000C asfollows:Weight % LOI 5I 2 F!I3 100 (1)where:I = initial sample weight, andF = final sample weight.7.4 Preparation of Test Sample for Atomic Absorption:7.4.1 Cautiously add 30 mL of sulfuric acid (3M) mixture tothe test sampl
32、e in the TFE-fluorocarbon beaker. Add 10 mL ofconcentrated hydrofluoric acid.7.4.2 Cover the beakers with TFE-fluorocarbon lids anddigest the samples on a hot plate at medium heat until all solidmaterial is in solution and light fumes are evolved.7.4.3 Allow the solutions to cool. Dilute to 70 mL wi
33、thdistilled water. Add 10 mL of aqua regia. Boil gently for a fewminutes.7.4.4 Allow the solutions to cool. Transfer quantitatively to500 mL volumetric flasks.Add 5 mL of the lanthanum chloridesolution.7.4.5 Dilute to volume when solutions have cooled to roomtemperature.7.4.6 Analyze the sample with
34、 an atomic absorption spec-trophotometer in the absorbance mode at 247.6 nm usingair-acetylene flame with background correction.7.4.7 Bracket the sample reading between appropriate cali-bration standards.NOTE 6Make certain that samples and standards are on the linearportion of the calibration curve.
35、 If a sample falls on the nonlinear portionof the curve, make appropriate dilution and matrix adjustments. Checkzero setting before each standard and sample reading using the 0 mg/Lstandard.8. Calculation of Results8.1 Calculate the weight percent of palladium in the testsample on a 1000C ignited ba
36、sis as follows:8.1.1 Method 1Plot the absorbance of the standards ver-sus the concentration of palladium in the standards. Determinethe concentration of palladium in the sample using the calibra-tion curve.8.1.2 Method 2The concentration of palladium in thesample solutions may be calculated as follo
37、ws:CS 5AS 2 AL! 3 CH 2 CL!AH 2 AL!1 CL (2)where:CS = mg/L of palladium in sample solution,AS = absorbance of the sample,AL = absorbance of lower standard,AH = absorbance of higher standard,CL = mg/L of palladium in the lower standard, andCH = mg/L of palladium in the higher standard.8.1.3 The concen
38、tration of palladium in the sample iscalculated as follows:Palladium, % 5CSF1.00 2% LOI100G3 W 3 20(3)where:CS = mg/L of palladium in sample solution,W = grams of sample, andLOI = average of duplicate loss on ignitions.9. Precision and Bias59.1 Test ProgramAn interlaboratory study was conductedin wh
39、ich the weight % palladium (volatile free basis) wasmeasured in one separate test material in eight separatelaboratories. Practice E691, modified for non-uniform datasets, was followed for the data reduction. Analysis details arein the research report.9.2 PrecisionPairs of test results obtained by a
40、 proceduresimilar to that described in the study are expected to differ inabsolute value by less than 2.772 S, where 2.772 S is the 95 %probability interval limit on the difference between two testresults, and S is the appropriate estimate of standard deviation.Definitions and usage are given in Ter
41、minology E456 andPractice E177, respectively.Test Result(Consensus Mean)weight %95 % RepeatabilityInterval(Within Laboratory)weight %95 % ReproducibilityInterval(Between Laboratories)weight %0.5406 0.005 (0.95 % of mean) 0.021 (3.94 % of mean)9.3 BiasThis test method is without known bias.10. Keywor
42、ds10.1 atomic absorption; molecular sieve; molecular sievecatalyst; palladiumASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validi
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45、t received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple cop
46、ies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D32-1034.D5153 103
