1、Designation: D 7442 08Standard Practice forSample Preparation of Fluid Catalytic Cracking Catalystsand Zeolites for Elemental Analysis by Inductively CoupledPlasma Atomic Emission Spectroscopy1This standard is issued under the fixed designation D 7442; the number immediately following the designatio
2、n indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers uniform dissol
3、ution techniques forpreparing samples of fluid catalytic cracking catalysts (FCC)and exchanged zeolitic materials for analysis by InductivelyCoupled Plasma Atomic Emission Spectroscopy (ICP-AES).These techniques describe standardized approaches to well-known, widely used laboratory practices of samp
4、le preparationutilizing acid digestions and borate salt fusions. This practice isapplicable to fresh and equilibrium FCC catalysts and ex-changed zeolite materials.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to
5、SI units that are provided for information onlyand are not considered standard.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 establish appro-priate safety and health practices and dete
6、rmine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Acronyms:2.1.1 FCCFluid Catalytic Cracking2.1.2 FCCUFluid Catalytic Cracking Unit2.1.3 ICP-AESInductively-Coupled Plasma-AtomicEmission Spectroscopy3. Summary of Practice3.1 Three preparation techniques are presented f
7、or convert-ing solid, power samples into clear, dilute acid solutionssuitable for analysis by ICP-AES. The three techniques pre-sented are Perchloric Acid Digestion, Sulfuric Acid Digestion,and Lithium-Borate Fused Dissolution. Other techniques maybe possible; however, these three approaches are est
8、ablished,widely used laboratory techniques for preparing FCC catalystand catalyst-like samples.3.2 Powder samples are heat-treated for 1 to3htoremovevolatile components prior to further preparation by any of thesethree techniques.3.3 The Perchloric Acid and Sulfuric Acid techniques in-volve dissolvi
9、ng small aliquots of heat-treated sample in therespective acid liquors and diluting the resulting solutions tothe appropriate analytical volume. These techniques requireboiling acid solutions in platinum or polytetrafluoroethylene(PTFE) labware and shall be used in appropriate fume hoods.The Perchlo
10、ricAcid Digestion shall never be used in a standardfume hood.3.4 The Lithium Borate Fused Dissolution technique in-volves dissolving small aliquots of heat-treated sample in amolten flux of lithium metaborate and lithium tetraborate salts,dissolving the resulting flux solution in a dilute nitric aci
11、dsolution, and diluting the clear, concentrated specimen solutionto an appropriate analytical volume. This technique must beperformed in an operational fume hood and can be performedmanually or may utilize the advantages of an automated fluxer.The optimal ratio of flux to sample, as well as fusionte
12、mperature needed, will vary depending on sample matrix.4. Significance and Use4.1 The chemical composition of catalyst and catalyst ma-terials is an important indicator of catalyst performance and isa valuable tool for assessing parameters in a FCCU process.This practice will be useful to catalyst m
13、anufacturers andpetroleum refiners for quality verification and performanceevaluation, and to environmental authorities at the state andfederal levels for evaluation and verification of various com-pliance programs.2, 3, 44.2 Catalysts and catalyst type materials are difficult toprepare for analysis
14、 by ICP, and although the techniquespresented in this practice are common, there is wide variationamong laboratories in sample pretreatment and digestion1This practice is under the jurisdiction of ASTM Committee D32 on Catalystsand is the direct responsibility of Subcommittee D32.03 on Chemical Comp
15、osition.Current edition approved April 1, 2008. Published April 2008.2Dean, John R., Practical Inductively Coupled Plasma Spectroscopy , JohnWiley, New York, 2005.3Gaines, Paul, “ICP Operations,” at .4Segal, Eileen B., “First Aid for a Unique Acid: HF,” Chemical Health andSafety, Sept/Oct 1998, Vol
16、 5, p. 25.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.recipes. This practice is intended to standardize these variablesin order to facilitate the utility of comparative data amongmanufacturers, refiners, and regulatory agencies.5
17、. Apparatus5.1 Muffle Furnaceat 1000 to 1100F (538 to 593C).5.2 Analytical Balance.5.3 Digestion Vesselsplatinum dish or PTFE beaker.5.4 Volumetric FlasksClass A glass, 250 mL.5.5 Automated Fusion Machinealternate to manual pro-cedure.5.6 CruciblePt95%/Au5%high-form.6. Reagents6.1 All reagents shoul
18、d conform to American ChemicalSociety (ACS) specifications.5Ultra high purity standards andreference materials are commercially available from recog-nized vendors.6.2 Perchloric Acid, concentrated, 69 to 72 %.6.3 Hydrofluoric Acid, concentrated, 48 %.6.4 Sulfuric Acid,H2SO4, concentrated, 94 %.6.5 N
19、itric Acid, HNO3, concentrated, 65 %.6.6 Hydrochloric Acid, 1:1 HCl (concentrated HCl, 38 %,diluted 1:1).6.7 Hydrogen Peroxide,3%.6.8 Lithium Borate Fluxes, lithium tetraborate, or metabo-rate, or both.6.9 Boric Acid Solution.7. Preparation of Powder Samples7.1 Catalysts and catalyst type sample pow
20、ders containsmall amounts of moisture and other volatile materials thatmust be removed to eliminate potential error in the analysis.Typically, 50 g of powder sample are heated in air in alaboratory furnace at 1000 to 1100F (538 to 593C) for 1 to3 h to remove volatile components prior to further prep
21、arationby any of these three techniques.7.2 The bed depth of catalyst during the heat treatmentshould typically be 1 in. or less. The heat-treated specimenshould be thoroughly blended upon cooling, since someparticle size segregation normally occurs during the heattreatment step.7.3 The heat-treated
22、 specimen should remain in a desiccatoruntil use to prevent re-adsorption of ambient moisture.8. Hazards8.1 Hazards Common to All Mineral Acids:8.1.1 Wear suitable gloves, eye protection, and properprotective clothing to protect in the event of splashes and spills.Dilutions shall be performed by add
23、ing acid to water, not theother way around. Limit quantities in storage to what is neededfor the next few weeks.8.1.2 Boiling acid solutions can be particularly dangerous,and the elevated temperature typically increases the severity ofthe hazardous properties. Particular care and advance prepara-tio
24、n shall be given to work with tasks involving acid solutionsunder these conditions.8.2 Hazards Specific to Perchloric Acid:8.2.1 When not handled properly, perchloric acid can be avery dangerous reagent. Digestions with perchloric acid shouldbe performed only in a fume hood specifically designed for
25、 itsunique hazards and properties. This hood shall have a waterwashdown system, operated according to the manufacturersspecifications and instructions. This system is required toprevent buildup of explosive perchlorate salts in the duct work.8.2.2 Solutions with perchloric acid shall never be boiled
26、 todryness. Careful, attentive observation of techniques usingperchloric acid is imperative for safe use.8.2.3 Perchloric acid should not be mixed or used withorganic materials if there is a possibility that the temperaturewill become elevated beyond ambient levels.8.2.4 In the event of a perchloric
27、 acid spill, neutralize withsoda ash or other appropriate neutralizing agent. Soak up withan inorganic based absorbent. DO NOT use rags, paper towels,saw dust, or any organic or oxidizable material, as suchmaterial may spontaneously ignite. An approved spill kit forperchloric acid is highly recommen
28、ded.8.3 Hazards Specific to Hydrofluoric Acid (HF):8.3.1 Hydrofluoric acid is an extremely hazardous liquidand vapor that causes severe burns which may not be imme-diately painful or visible. It may also be fatal if swallowed orinhaled. The liquid and vapor can burn skin, eyes, andrespiratory tract
29、and cause bone damage.8.3.2 Calcium gluconate ointment should be kept in thework area for application in the event of accidental contactwith HF. In case of HF contact with any body parts, wash theaffected area immediately with cold water and then liberallyapply the calcium gluconate gel. Seek prompt
30、 medical treat-ment.8.4 Molten fluxes have the potential of liberating andvolatilizing hazardous respiratory agents. Work involving thesemolten solutions shall be done only in functional fume hoodswith additional protection from skin contact and spattering.8.5 Analysts should avoid the dust produced
31、 by samples. Aventilated balance area or a dust mask should be utilized whenweighing large numbers of samples.9. ProceduresPerchloric Acid Digestion Procedure9.1 Accurately measure 1.0 g of sample into a clean, drydigestion vessel (5.3).9.2 Add 20 mL of perchloric acid (HClO4) and 25 mL ofhydrofluor
32、ic acid.9.3 Heat on a hot plate in a perchloric acid fume hood untilheavy fumes are visible.9.4 Cool and add 15 mL boric acid solution (H3BO3), andheat to fumes again. This step is required to completelyeliminate residual HF, as subsequent steps utilize glass vessels.5Reagent Chemicals, American Che
33、mical 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., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. P
34、harmacopeial Convention, Inc. (USPC), Rockville,MD.D74420829.5 Remove from heat and assess the condition of thesolution; a clear solution without undissolved sample solids isdesired. If digestion is complete, proceed to 9.8.9.6 If a clear solution does not exist, transfer the solution toa 400-mL bea
35、ker.9.7 Carefully add 100 mL of deionized (DI) water and 10mL of hydrochloric acid (HCl). Cover with a watch glass, andboil on the hot plate until full digestion is complete.9.8 Cool to ambient temperature, and quantitatively transferto a 250-mL volumetric flask.9.9 Add internal standard aliquot, if
36、 required.9.10 Mix well and dilute to volume. Submit for ICPanalysis.Sulfuric Acid Digestion Procedure9.11 Accurately measure 1.0 g of heat-treated sample into aclean, dry digestion vessel.9.12 Add 10 mL of sulfuric acid, 10 mL of nitric acid, and25 mL of hydrofluoric acid.9.13 Heat on a hot plate i
37、n a fume hood, and evaporate tonear dryness.9.14 Cool to near ambient temperature, and quantitativelytransfer solution to a 400-mL digestion vessel.9.15 Add 20 mL of 19 % hydrochloric acid and 30 mL of3 % hydrogen peroxide.9.16 Cover with watch glass and heat on hot plate in fumehood to boiling unti
38、l all of the salts are dissolved.9.17 Cool to ambient and quantitatively transfer to a250-mL volumetric flask.9.18 Add internal standard aliquot, if required, and 10 mLofhydrochloric acid.9.19 Mix well and dilute to volume. Submit for ICPanalysis.Lithium Borate Flux Dissolution Procedure9.20 Accurat
39、ely measure 0.1 to 1.0 g of heat-treated sampleinto a clean, dry crucible (5.6).9.21 Add 5.0 g of lithium borate flux to the sample. Theoptimal ratio (flux:sample of 5:1, 10:1, 20:1) and temperatureneeded for successful fusion will vary depending on samplematrix; adjust sample size to appropriate ra
40、tio. Keep the weightof borate flux used constant, and adjust the weight of sample toobtain optimal ratio.9.22 Thoroughly mix sample and flux using a platinum wireas a stir rod.9.23 Heat for 20 min in a 1650F (950C) muffle furnace.9.24 Cool to ambient temperature in a desiccator.9.25 Heat a solution
41、of 100 mL deionized water and 10 mLconcentrated nitric acid in a suitable laboratory beaker, tosimmering on a hot plate in a fume hood.9.26 Transfer the fused sample plug to the beaker withattentive care to avoid splashing the hot acid solution.9.27 Continue heating, with occasional stirring, until
42、theentire fused plug is dissolved.9.28 Cool to ambient and quantitatively transfer to a250-mL volumetric flask.9.29 Add internal standard aliquot, if required.9.30 Mix well and dilute to volume. Submit for ICPanalysis.10. Precision and Bias10.1 This practice purports only to standardize the approach
43、to sample preparations and does not provide for quantitativedetermination of any sample characteristics. As such, there areno parameters measured, and it is not possible to determinestatistical precision or bias of the techniques discussed herein.11. Keywords11.1 acid decomposition; atomic spectrosc
44、opy; fusion; cata-lyst; fluid catalytic cracking; hydrofluoric acid; inductively-coupled plasma emission spectroscopy; perchloric acid;zeolitesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of th
45、is standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five ye
46、ars andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical commi
47、ttee, which you may attend. If you feel that your comments have not 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 copies) 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).D7442083
