1、Designation: D 7442 08aStandard 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 designati
2、on 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers uniform disso
3、lution 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 sam
4、ple 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 SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This st
5、andard 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 determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Acronyms
6、: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 for convert-ing solid, power samples into clear, dilute acid solutionssuitable for analysis
7、 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 established,widely used laboratory techniques for preparing FCC catalystand catalyst-like sam
8、ples.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 dissolving small aliquots of heat-treated sample in therespective acid liquors and diluting the re
9、sulting 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 PerchloricAcid Digestion shall never be used in a standardfume hood.3.4 The Lithium Borate Fused
10、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 acidsolution, and diluting the clear, concentrated specimen solutionto an appropriate analyti
11、cal 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 fusiontemperature needed, will vary depending on sample matrix.4. Significance and Use4.1 The chem
12、ical 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 manufacturers andpetroleum refiners for quality verification and performanceevaluation, and
13、 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 by ICP, and although the techniquespresented in this practice are common, there is wide v
14、ariationamong 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 Composition.Current edition approved Sept. 1, 2008. Published September 2008. Originallyapprov
15、ed in 2008. Last previous edition approved in 2008 as D 744208.2Dean, 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, Vol 5, Sept/Oct 1998, p.
16、25.1*A Summary of Changes section appears at the end of this standard.Copyright 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 d
17、ata amongmanufacturers, refiners, and regulatory agencies.5. Apparatus5.1 Muffle Furnaceat 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%
18、high-form.6. Reagents6.1 All reagents should 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 Su
19、lfuric Acid,H2SO4, concentrated, 94 %.6.5 Nitric 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, 2 to 3 %.7. Preparation of Pow
20、der Samples7.1 Catalysts and catalyst type sample powders 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 538 to 593C for 1 to3htoremovevolatile
21、 components prior to further preparation by any of thesethree techniques.7.2 The bed depth of catalyst during the heat treatmentshould typically be 25.4 mm or less. The heat-treated specimenshould be thoroughly blended upon cooling, since someparticle size segregation normally occurs during the heat
22、treatment step.7.3 The heat-treated 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.
23、Dilutions shall be performed by adding 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. Part
24、icular care and advance prepara-tion 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
25、fume hood specifically designed for 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 pe
26、rchloric acid shall never be boiled 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
27、.8.2.4 In the event of a perchloric 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 fo
28、rperchloric acid is highly recommended.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 bur
29、n skin, eyes, andrespiratory tract 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
30、 calcium gluconate gel. Seek prompt 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 Anal
31、ysts should avoid the dust produced 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
32、acid (HClO4) and 25 mL ofhydrofluoric 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 vesse
33、ls.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical 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 Pharmac
34、opeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 7442 08a29.5 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
35、, transfer the solution toa 400-mL beaker.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
36、.9.9 Add internal standard aliquot, if 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 hydrof
37、luoric acid.9.13 Heat on a hot plate in 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
38、 hot plate in fumehood to boiling until 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
39、Flux Dissolution Procedure9.20 Accurately 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
40、; adjust sample size to appropriate ratio. 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 950C muffle furnace.9.24 Cool to ambient temperature in a de
41、siccator.9.25 Heat a solution 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, wi
42、th occasional stirring, until 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 on
43、ly to standardize the approachto 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 d
44、ecomposition; atomic spectroscopy; fusion; cata-lyst; fluid catalytic cracking; hydrofluoric acid; inductively-coupled plasma emission spectroscopy; perchloric acid;zeolitesSUMMARY OF CHANGESCommittee D32 has identified the location of selected changes to this standard since the last issue (D 744208
45、)that may impact the use of this standard.(1) Modified 6.9.ASTM 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 validity of any such pat
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48、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).D 7442 08a3
