1、Designation: D7442 08aD7442 16Standard Practice forSample Preparation of Fluid Catalytic Cracking Catalystsand Zeolites for Elemental Analysis by Inductively CoupledPlasma AtomicOptical Emission Spectroscopy1This standard is issued under the fixed designation D7442; the number immediately following
2、the designation 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
3、uniform dissolution techniques for preparing samples of fluid catalytic cracking catalysts (FCC) andexchanged zeolitic materials for analysis by Inductively Coupled Plasma AtomicOptical Emission Spectroscopy (ICP-AES).(ICP-OES). These techniques describe standardized approaches to well-known, widely
4、 used laboratory practices of sample preparationutilizing acid digestions and borate salt fusions. This practice is applicable to fresh and equilibrium FCC catalysts and exchangedzeolite materials.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are inc
5、luded in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior t
6、o use.2. Referenced Documents2.1 ASTM Standards:2D7260 Practice for Optimization, Calibration, and Validation of Inductively Coupled Plasma-Atomic Emission Spectrometry(ICP-AES) for Elemental Analysis of Petroleum Products and Lubricants3. Terminology3.1 Acronyms:3.1.1 FCCFluid Catalytic Cracking3.1
7、.2 FCCUFluid Catalytic Cracking Unit3.1.3 ICP-AESICP-OESInductively-Coupled Plasma-AtomicPlasma-Optical Emission Spectroscopy4. Summary of Practice4.1 Three preparation techniques are presented for converting solid, power samples into clear, dilute acid solutions suitable foranalysis by ICP-AES.ICP-
8、OES. The three techniques presented are Perchloric Acid Digestion, Sulfuric Acid Digestion, andLithium-Borate Fused Dissolution. Other techniques may be possible; however, these three approaches are established, widelyused laboratory techniques for preparing FCC catalyst and catalyst-like samples.4.
9、2 Powder samples are heat-treated for 1 to 3 h to remove volatile components prior to further preparation by any of these threetechniques.4.3 The Perchloric Acid and Sulfuric Acid techniques involve dissolving small aliquots of heat-treated sample in the respectiveacid liquors and diluting the resul
10、ting solutions to the appropriate analytical volume. These techniques require boiling acidsolutions in platinum or polytetrafluoroethylene (PTFE) labware and shall be used in appropriate fume hoods. The PerchloricAcidDigestion shall never be used in a standard fume hood.1 This practice is under the
11、jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.03 on Chemical Composition.Current edition approved Sept. 1, 2008March 1, 2016. Published September 2008April 2016. Originally approved in 2008. Last previous edition approved in 2008 asD744208.08a.
12、DOI: 10.1520/D7442-08A.10.1520/D7442-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not
13、an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate.
14、 In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.4
15、The Lithium Borate Fused Dissolution technique involves dissolving small aliquots of heat-treated sample in a molten fluxof lithium metaborate and lithium tetraborate salts, dissolving the resulting flux solution in a dilute nitric acid solution, and dilutingthe clear, concentrated specimen solution
16、 to an appropriate analytical volume. This technique must be performed in an operationalfume hood and can be performed manually or may utilize the advantages of an automated fluxer. The optimal ratio of flux tosample, as well as fusion temperature needed, will vary depending on sample matrix.5. Sign
17、ificance and Use5.1 The chemical composition of catalyst and catalyst materials is an important indicator of catalyst performance and is avaluable tool for assessing parameters in a FCCU process. This practice will be useful to catalyst manufacturers and petroleumrefiners for quality verification an
18、d performance evaluation, and to environmental authorities at the state and federal levels forevaluation and verification of various compliance programs.3, 4, 55.2 Catalysts and catalyst type materials are difficult to prepare for analysis by ICP, and although the techniques presented inthis practic
19、e are common, there is wide variation among laboratories in sample pretreatment and digestion recipes. This practiceis intended to standardize these variables in order to facilitate the utility of comparative data among manufacturers, refiners, andregulatory agencies.6. Apparatus6.1 Muffle Furnaceat
20、 538 to 593C.6.2 Analytical Balance.6.3 Digestion Vesselsplatinum dish or PTFE beaker.6.4 Volumetric FlasksClass A glass, 250 mL.6.5 Automated Fusion Machinealternate to manual procedure.6.6 CruciblePt95%/Au5% high-form.7. Reagents7.1 All reagents should conform toAmerican Chemical Society (ACS) spe
21、cifications.6 Ultra high purity standards and referencematerials are commercially available from recognized vendors.7.2 Perchloric Acid, concentrated, 69 to 72 %.7.3 Hydrofluoric Acid, concentrated, 48 %.7.4 Sulfuric Acid, H2SO4, concentrated, 94 %.7.5 Nitric Acid, HNO3, concentrated, 65 %.7.6 Hydro
22、chloric Acid, 1:1 HCl (concentrated HCl, 38 %, diluted 1:1).7.7 Hydrogen Peroxide, 3 %.7.8 Lithium Borate Fluxes, lithium tetraborate, or metaborate, or both.7.9 Boric Acid Solution, 2 to 3 %.8. Preparation of Powder Samples8.1 Catalysts and catalyst type sample powders contain small amounts of mois
23、ture and other volatile materials that must beremoved to eliminate potential error in the analysis. Typically, 50 g of powder sample are heated in air in a laboratory furnace at538 to 593C for 1 to 3 h to remove volatile components prior to further preparation by any of these three techniques. If sa
24、mplecontains organic materials, pretreatment is recommended prior to placing the sample at 538 to 593C.8.2 The bed depth of catalyst during the heat treatment should typically be 25.4 mm or less. The heat-treated specimen shouldbe thoroughly blended upon cooling, since some particle size segregation
25、 normally occurs during the heat treatment step.8.3 The heat-treated specimen should remain in a desiccator until use to prevent re-adsorption of ambient moisture.9. Hazards9.1 Hazards Common to All Mineral Acids:3 Dean, John R., Practical Inductively Coupled Plasma Spectroscopy, John Wiley, New Yor
26、k, 2005.4 Gaines, Paul, “ICP Operations,” at .5 Segal, Eileen B., “First Aid for a Unique Acid: HF,” Chemical Health and Safety, Vol 5, Sept/Oct 1998, p. 25.6 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of re
27、agents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC),(USP), Rockville, MD.D7442 1629.1.1 Wear suitable gloves, eye protecti
28、on, and proper protective clothing to protect in the event of splashes and spills. Dilutionsshall be performed by adding acid to water, not the other way around. Limit quantities in storage to what is needed for the nextfew weeks.9.1.2 Boiling acid solutions can be particularly dangerous, and the el
29、evated temperature typically increases the severity of thehazardous properties. Particular care and advance preparation shall be given to work with tasks involving acid solutions under theseconditions.9.2 Hazards Specific to Perchloric Acid:9.2.1 When not handled properly, perchloric acid can be a v
30、ery dangerous reagent. Digestions with perchloric acid should beperformed only in a fume hood specifically designed for its unique hazards and properties. This hood shall have a water washdownsystem, operated according to the manufacturers specifications and instructions. This system is required to
31、prevent buildup ofexplosive perchlorate salts in the duct work.9.2.2 Solutions with perchloric acid shall never be boiled to dryness. Careful, attentive observation of techniques usingperchloric acid is imperative for safe use.9.2.3 Perchloric acid should not be mixed or used with organic materials
32、if there is a possibility that the temperature will becomeelevated beyond ambient levels.9.2.4 In the event of a perchloric acid spill, neutralize with soda ash or other appropriate neutralizing agent. Soak up with aninorganic based absorbent. DO NOT use rags, paper towels, saw dust, or any organic
33、or oxidizable material, as such material mayspontaneously ignite. An approved spill kit for perchloric acid is highly recommended.9.3 Hazards Specific to Hydrofluoric Acid (HF):9.3.1 Hydrofluoric acid is an extremely hazardous liquid and vapor that causes severe burns which may not be immediatelypai
34、nful or visible. It may also be fatal if swallowed or inhaled. The liquid and vapor can burn skin, eyes, and respiratory tract andcause bone damage.9.3.2 Calcium When working with HF, each individual lab must have its own safety procedures handling accidental contact,inhalation, and spill. For examp
35、le, calcium gluconate ointment should be kept in the work area for application in the event ofaccidental contact with HF. In case of HF contact with any body parts, wash the affected area immediately with cold water andthen liberally apply the calcium gluconate gel. Seek prompt medical treatment.9.4
36、 Molten fluxes have the potential of liberating and volatilizing hazardous respiratory agents. Work involving these moltensolutions shall be done only in functional fume hoods with additional protection from skin contact and spattering.9.5 Analysts should avoid the dust produced by samples. A ventil
37、ated balance area or a dust mask should be utilized whenweighing large numbers of samples.10. ProceduresPerchloric Acid Digestion Procedure10.1 Accurately measure 1.0 g of sample into a clean, dry digestion vessel (5.36.3).10.2 Add 20 mL of perchloric acid (HClO4) and 25 mL of hydrofluoric acid.10.3
38、 Heat on a hot plate in a perchloric acid fume hood until heavy fumes are visible.10.4 Cool and add 15 mL boric acid solution (H3BO3), and heat to fumes again. This step is required to completely eliminateresidual HF, as subsequent steps utilize glass vessels.10.5 Remove from heat and assess the con
39、dition of the solution; a clear solution without undissolved sample solids is desired.If digestion is complete, proceed to 9.810.8.10.6 If a clear solution does not exist, transfer the solution to a 400-mL beaker.10.7 Carefully add 100 mL of deionized (DI) water and 10 mL 10 mL of hydrochloric acid
40、(HCl). Cover with a watch glass,and boil on the hot plate until full digestion is complete.10.8 Cool to ambient temperature, and quantitatively transfer to a 250-mL volumetric flask.10.9 Add internal standard aliquot, if required.10.10 Mix well and dilute to volume. Submit for ICP analysis.Sulfuric
41、Acid Digestion Procedure10.11 Accurately measure 1.0 g of heat-treated sample into a clean, dry digestion vessel.10.12 Add 10 mL of sulfuric acid, 10 mL of nitric acid, and 25 mL of hydrofluoric acid.10.13 Heat on a hot plate in a fume hood, and evaporate to near dryness.10.14 Cool to near ambient t
42、emperature, and quantitatively transfer solution to a 400-mL digestion vessel.D7442 16310.15 Add 20 mL of 19 % hydrochloric acid and 30 mL of 3 % hydrogen peroxide.10.16 Cover with watch glass and heat on hot plate in fume hood to boiling until all of the salts are dissolved.10.17 Cool to ambient an
43、d quantitatively transfer to a 250-mL volumetric flask.10.18 Add internal standard aliquot, if required, and 10 mL of hydrochloric acid.10.19 Mix well and dilute to volume. Submit for ICP analysis.Lithium Borate Flux Dissolution Procedure10.20 Accurately measure 0.1 to 1.0 g of heat-treated sample i
44、nto a clean, dry crucible (5.66.6).10.21 Add 5.0 g of lithium borate flux to the sample. The optimal ratio (flux:sample of 5:1, 10:1, 20:1) and temperature neededfor successful fusion will vary depending on sample matrix; adjust sample size to appropriate ratio. Keep the weight of borate fluxused co
45、nstant, and adjust the weight of sample to obtain optimal ratio.10.22 Thoroughly mix sample and flux using a platinum wire as a stir rod.10.23 Heat for 20 min in a 950C muffle furnace.10.24 Cool to ambient temperature in a desiccator.10.25 Heat a solution of 100 mL deionized water and 10 mL concentr
46、ated nitric acid in a suitable laboratory beaker, tosimmering on a hot plate in a fume hood.10.26 Transfer the fused sample plug to the beaker with attentive care to avoid splashing the hot acid solution.10.27 Continue heating, with occasional stirring, until the entire fused plug is dissolved.10.28
47、 Cool to ambient and quantitatively transfer to a 250-mL volumetric flask.10.29 Add internal standard aliquot, if required.10.30 Mix well and dilute to volume. Submit for ICP analysis.analysis following Practice D7260.11. Precision and Bias11.1 This practice purports only to standardize the approach
48、 to sample preparations and does not provide for quantitativedetermination of any sample characteristics. As such, there are no parameters measured, and it is not possible to determinestatistical precision or bias of the techniques discussed herein.12. Keywords12.1 acid decomposition; atomic spectro
49、scopy; fusion; catalyst; fluid catalytic cracking; fusion; 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(D744208)08a) that may impact the use of this standard.(1) Modified 6.9.title.(2) Added Referenced Documents Section 2.(3) Modified the following sections: 1.1, 3.1.3, 4.1, 8.1, 9.3.2, and 10.30.ASTM International takes no posi
