1、Designation: G 120 01 (Reapproved 2008)Standard Practice forDetermination of Soluble Residual Contamination bySoxhlet Extraction1This standard is issued under the fixed designation G 120; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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 describes a procedure for the determina-tion of residual contamination in systems and c
3、omponentsrequiring a high level of cleanliness, such as oxygen, bySoxhlet extraction.1.2 This practice may be used for extracting nonvolatile andsemivolatile residues from solids such as new and used gloves,new and used wipes, contaminated test specimens or controlcoupons, small pieces of hardware,
4、component softgoods, etc.When used with proposed cleaning materials (wipes, gloves,etc.), from the cleaning materials this practice may be used todetermine the potential of the proposed solvent to extractcontaminants (plasticizers, residual detergents, brighteners,etc.) and deposit them on the surfa
5、ce being cleaned.1.3 This practice is not suitable for the evaluation ofparticulate contamination.1.4 The values stated in SI units are standard.1.5 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 stand
6、ard 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:2D 1193 Specification for Reagent WaterE 1235 Test Method for Gravimetric Determination of Non-volatile Residue (NVR) in Environ
7、mentally ControlledAreas for SpacecraftF 331 Test Method for Nonvolatile Residue of SolventExtract from Aerospace Components (Using Flash Evapo-rator)G93 Practice for Cleaning Methods and Cleanliness Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironments3. Terminology3.1 Definitions:3.
8、1.1 contaminant, nunwanted molecular and particulatematter that could affect the performance of the components ormaterials upon which they reside.3.1.2 contamination, na process of contaminating.3.1.3 nonvolatile residue (NVR), nresidual molecular andparticulate matter remaining following the filtra
9、tion of asolvent containing contaminants and complete evaporation ofthe solvent at a specified temperature.3.1.4 particle (particulate contaminant), n a piece ofmatter in a solid state with observable length, width, andthickness.3.1.4.1 DiscussionThe size of a particle is usually definedby its great
10、est dimension and is specified in micrometres.3.1.5 molecular contaminant , nnon-particulate contami-nation.3.1.5.1 DiscussionA molecular contaminant may be in agaseous, liquid, or solid state and may be uniformly ornonuniformly distributed.3.1.5.2 DiscussionMolecular contaminants account formost of
11、 the NVR.3.1.6 control coupon (witness coupon), n a coupon madefrom the same material and prepared in exactly the same wayas the test coupons, which is used to verify the validity of themethod or part thereof.3.1.6.1 DiscussionIn this test method, the control couponwill be contaminated in the same m
12、anner as the test couponsand will be subjected to the identical extraction procedure.4. Summary of Practice4.1 The sample is placed in an extraction thimble orbetween two plugs of glass wool and contaminants are ex-tracted using an appropriate solvent in a Soxhlet extractor. The1This practice is und
13、er the jurisdiction of ASTM Committee G04 on Compat-ibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and is thedirect responsibility of Subcommittee G04.02 on Recommended Practices.Current edition approved Sept. 1, 2008. Published October 2008. Originallyapproved in 1993. Last pre
14、vious edition approved in 2001 as G 120 01.2For 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 standards Document Summary page onthe ASTM website.1Copyright ASTM In
15、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.solvent is brought to the boiling point; the pure solvent vaporstravel to the condenser where they condense and drip into thethimble. When the liquid level in the thimble reaches the top ofthe Soxhlet si
16、phon, the solvent and extracted soluble contami-nant are siphoned back into the boiler. This process is allowedto continue for several hours. The solvent and extract are thenconcentrated or dried for analysis.5. Significance and Use5.1 It is expected that this practicewill be suitable to identifyand
17、 quantify contaminants found in systems, system materials,and components used in systems requiring a high level ofcleanliness, such as oxygen. Softgoods such as seals and valveseats can be tested as received. Gloves and wipes, or samplesthereof, to be used in the cleaning operation can be evaluatedp
18、rior to use to ensure that the proposed cleaning solvent doesnot extract contaminants and residues on the surface to becleaned.5.2 Wipes or other cleaning equipment can be tested afteruse to determine the amount of contaminant removed from asurface. This procedure can be used to obtain samples for N
19、VRanalysis using contaminated control coupons that were sub-jected to the cleaning process as controls to validate cleaningoperations.5.3 The selection of the solvent requires some knowledge ofthe contaminant (see Practice G93for recommendations). If anonvolatile residue (NVR) analysis is to be perf
20、ormed on themolecular contaminant, the boiling point of the solvent shall besignificantly lower than that of the contaminant. For otheranalytical methods, the tester must know the accuracy of theanalytical methods, and the solvent shall be chosen so as not tointerfere with the selected analytical me
21、thod. To identify thecomposition of the NVR, analytical methods such as infraredspectroscopy or gas chromatography/mass spectroscopy havebeen used satisfactorily.6. Apparatus6.1 Soxhlet extractor500 mL evaporation flask and asso-ciated equipment as shown in Fig. 1.6.2 Boiling chipssolvent extracted.
22、6.3 Water bathheated with temperature control of 65 C.6.4 Thimblesglass or paper.6.5 Heating mantlerheostat controlled.6.6 Balancerange to a minimum of 50 g with an accuracyof 0.1 mg.6.7 Evaporatorrotary.6.8 500 mL concentrator flask.7. Reagents7.1 Solvents that can be used to prepare standard conta
23、mi-nant solutions include the following: 2-propanol, 2-butanone,hexane, methylene chloride, and perfluorinated carbon fluids.7.2 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Commi
24、ttee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.NOTE 1Warning: Solvents su
25、ch as 2-propanol and 2-butanone arehighly flammable. The reader should refer to appropriate safe handlingprocedures.7.3 Watershall meet the requirements of D 1193, Type II.8. Procedure8.1 Prepare the sample for placement in the extractor.8.1.1 To determine the amount of extractable material in awipi
26、ng cloth (new or used), cut out a test section approximately30 centimetres (cm) square, accurately measure and calculatethe area (A) in square centimetres, and weigh the section ingrams to the nearest tenth of a milligram (W1). Record the areaand weight.8.1.1.1 If the NVR is to be determined on a us
27、ed wipingcloth in an effort to assess the cleanliness of a part or system,a NVR analysis shall be performed on an unused representative3Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the
28、American Chemical Society, see Analytical Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.FIG. 1 Soxhlet Extraction ApparatusG 120 01 (2008)2sample of the cloth, with
29、 the same surface area, prior to useaccording to Test Method E 1235or Test Method F 331. Recordthis NVR as W3in mg/g or as W4in mg/cm2. This NVR valuemust be subtracted from that determined for the contaminatedcloth.8.1.2 To determine the amount of extractable material in aglove to be used in a clea
30、ning operation, cut several rectangularstrips from the fingers and palm, the areas that would typicallybe exposed to the cleaning solvent, weigh in grams to thenearest tenth of a milligram and record the weight (W1).Determine the dimensions of each strip in cm and record thetotal surface area of the
31、 strips (A) in square centimetres.8.1.3 To determine the amount of NVR on control coupons,measure the total contaminated surface area (i.e., front, orfront, back, and sides) in square centimetres and weigh ingrams to the nearest tenth of a milligram. Record the surfacearea (A) and weight (W1).8.1.4
32、To determine the amount of NVR on small parts,measure and record the total surface area (A) in squarecentimetres and weight in grams to nearest tenth of a milligram(W1) to be evaluated.8.2 Place the material to be extracted in an extractionthimble or between two glass wool plugs in the extractor.8.2
33、.1 The glass wool used for the plugs shall be washedprior to use with the solvent to be used for the extraction.8.3 Place 300 mL of the extraction solvent into the 500 mLflat bottom boiling flask containing one or two clean boilingchips. Place the flask in a heating mantle (or water bath that canbe
34、heated 15 to 20 C above the boiling point of the solvent)and attach the extractor to the flask.Attach the condenser to theextractor, turn on the cooling water to the condenser, bring theflask to a boil and extract the sample for six hours.8.3.1 Extract especially thick or dense materials overnight.I
35、f any doubt exists, it is recommended that extractions beperformed for different times (on new samples each time) toverify that the shorter extraction time removed all the extract-ables.8.4 Allow the extract to cool after the extraction is com-plete.8.5 Assemble the rotary evaporator.8.6 Carefully p
36、our the extract from the 500 mL boiling flaskinto the 500 mLconcentrator flask. Rinse the 500 mLflask with25 to 50 mL portions of fresh reagent grade extraction solventand add the rinse solution to the concentrator flask. Repeat therinse process two more times to complete the quantitativetransfer.8.
37、7 Attach the concentrator flask to the rotary evaporator.Partially immerse the flask in a water bath approximately 15 to20 C above the boiling point of the solvent. When theapparent volume of liquid reaches approximately 5 mL, re-move the flask from the water bath and allow the flask to coolfor at l
38、east ten minutes at room temperature.8.8 Determine the weight (W2) of the nonvolatile residue ingrams to the nearest tenth of a milligram using Test MethodE 1235 or Test Method F 331.9. Calculation9.1 Calculate the nonvolatile residue as follows:9.1.1 For new materials, wipes, gloves, etc., the tota
39、l NVRper unit weight is:NVR 51000*W2W1(1)where:NVR = nonvolatile residue, mg/g sample,W1= weight of the sample prior to extraction, g, andW2= weight of the nonvolatile residue, g.9.1.2 For new materials, wipes, gloves, etc., NVR by unitarea is:NVR 51000*W2A(2)where:NVR = nonvolatile residue, mg/cm2o
40、f sample,A = surface area of the sample, cm2, andW2= weight of the nonvolatile residue, g.9.1.3 For used material, the total NVR per unit weight in is:NVR 51000*W2W12 W3(3)where:NVR = nonvolatile residue, mg/cm2of sample,W1= weight of the sample prior to extraction, g,W2= weight of the nonvolatile r
41、esidue, g, andW3= NVR of new sample, mg/g.9.1.4 For used material, the total NVR per unit area is:NVR 51000*W2A2 W4(4)where:NVR = nonvolatile residue, mg/cm2of sample,W2= weight of the nonvolatile residue, g,A = surface area of the sample, cm2, andW4= NVR of new sample, mg/cm2.10. Report10.1 The rep
42、ort shall include the following:10.1.1 Identification of the material being extracted (includ-ing tradename, proper chemical name, ASTM designation, lotnumber, batch number, and manufacturer),10.1.2 Extraction solvent,10.1.3 Extraction time,10.1.4 Evaporation temperature,10.1.5 Method used to determ
43、ine the weight of the NVR,10.1.6 Value of the NVR (using formula 1, 2, 3 or 4).11. Precision and Bias11.1 PrecisionThe precision of the procedure in PracticeG 120 is being determined.11.2 BiasSince there is no accepted reference material fordetermining the bias for the procedure in Practice G 120 bi
44、ashas not been determined.12. Keywords12.1 contaminant; contamination; extraction; nonvolatileresidue; oxygen systems; Soxhlet extractionG 120 01 (2008)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. U
45、sers of this 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 eve
46、ry five years 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 techn
47、ical committee, 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).G 120 01 (2008)4
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