1、Designation: E832 81 (Reapproved 2013)Standard Specification forLaboratory Filter Papers1This standard is issued under the fixed designation E832; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers two types of filter paper for usein
3、 chemical analysis and provides procedures for the completeevaluation of the filter papers.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Referenced Documents2.1 ASTM Standards:2D774/D774M Test Method for Bursting Streng
4、th of Paper(Withdrawn 2010)32.2 TAPPI Standards:4T 413 Ash in PaperT 429 Alpha-Cellulose in PaperT 509 Hydrogen Ion Concentration (pH) of Paper ExtractsCold Extraction Method3. Types and Classes3.1 The types and classes of filter paper are as follows:3.1.1 Type ITo be used for qualitative analysis (
5、low ashcontent):3.1.1.1 Class AA, for very coarse and gelatinousprecipitates, very fast flow rate.3.1.1.2 Class A, for coarse and gelatinous precipitates, fastflow rate.3.1.1.3 Class B, for medium-size precipitates, medium flowrate.3.1.1.4 Class C, for fine precipitates, slow flow rate.3.1.1.5 Class
6、 D, hardened to facilitate scraping, for fineprecipitates, slow flow rate.3.1.2 Type IIto be used for quantitative analysis (ashlesspapers):3.1.2.1 Class E, for coarse and gelatinous precipitates, fastflow rate.3.1.2.2 Class F, for medium-size precipitates, medium flowrate.3.1.2.3 Class G, for fine
7、precipitates, slow flow rate.4. Manufacture4.1 The papers shall be made from such materials and bysuch methods as to ensure compliance with the requirements ofSection 10, and shall be clean and free of imperfections thatwould affect their performance.4.2 The papers shall be converted into circles, s
8、heets, or anyrequired sizes.5. General Requirements5.1 All classes of filter paper shall comply with the require-ments given in Table 1 and Table 2 and Section 11.5.2 The ash content of the Type II circles shall not exceed0.01 %.5.3 Class D filter papers shall have a surface hard enough topermit scr
9、aping collected precipitates off the sheet.6. Sampling6.1 If testing is required, the sample of each class shall berepresentative of the shipment, and specimens shall be taken atrandom from at least 3 % of the total packages.7. Retests7.1 If the results of the tests indicate noncompliance withthe re
10、quirements of Table 1 and Table 2, or other factorsdescribed within this specification, take another representativesample of the shipment, selecting the specimens from differentpackages than those from which the first sample was taken.7.2 Then test the second sample for compliance with thisspecifica
11、tion.1This specification is under the jurisdiction of ASTM Commmittee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved Nov. 1, 2013. Published December 2013. Originallyapproved in 1950. Last previous edition approved in 2008 as E
12、832 81 (2008).DOI: 10.1520/E0832-81R13.2For 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.3The last approved ver
13、sion of this historical standard is referenced onwww.astm.org.4Available from Technical Association of the Pulp and Paper Industry (TAPPI),15 Technology Parkway South, Norcross, GA 30092, http:/www.tappi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1942
14、8-2959. United States17.3 If the results of the retests indicate noncompliance withthis specification, immediately consult the manufacturer forassistance in rectifying the problem.8. Packaging and Marking8.1 Flat circles of filter paper shall be packaged in units of100 circles of the same diameter.
15、Prefolded or fluted circlesshall be packaged according to trade custom.8.2 Each unit or package shall be marked with the manu-facturers name, size of circles, or catalog and lot number.9. Test Methods9.1 The most important tests to be performed are:9.1.1 pH ValueDetermine in accordance with TAPPIMet
16、hod T 509.9.1.2 Alpha-CelluloseDetermine in accordance withTAPPI Method T 429. This test may or may not be used for lotto lot determination.9.1.3 Ash ContentDetermine in accordance with Section10.1 or TAPPI Method T 413, applicable for Type II papers.9.1.4 Retention of precipitates, simple method to
17、 determineretention ability of filter paper as determined in accordancewith 10.2.9.1.5 Water Flow RateDetermine the flow rates of filterpaper in accordance with 10.3 or the Herzberg method (mea-surement of time for the filtration of 100 mL of prefiltereddistilled water with a filter surface of 10 cm
18、2at a constantpressure of 50 mm water column).9.1.6 Wet Bursting StrengthDetermine in accordance with10.4.10. Test Methods10.1 Ash Content:10.1.1 Apparatus:10.1.1.1 Crucibles, 20-mL platinum, with tightly fittingcovers. One for each sample.10.1.1.2 Heat SourceAn electric muffle furnace with anoperat
19、ing temperature of approximately 925C isrecommended, but a gas burner yielding a similar temperatureis sufficient.10.1.1.3 Test specimens, having a mass of at least 6 g,representative of the sample obtained as prescribed in Section6, and cut in the shape of whole circles of the same diameter orsmall
20、 strips measured for area.10.1.2 Procedure:10.1.2.1 Heat the crucibles with their respective covers toapproximately 925C. Cool in a desiccator and weigh to thenearest 0.1 mg. Add the specimen into crucible.10.1.2.2 Heat the covered crucible plus test specimen gradu-ally until smoking ceases, remove
21、cover, then continue heatinguntil the maximum temperature of 925C is reached andmaintain for 2 h. Replace the cover and cool the coveredcrucible in a desiccator until temperature equilibrium with thesurrounding air is reached. Weigh the crucible and contents tothe nearest 0.1 mg. Ignition is conside
22、red to be complete whenthe weight of the covered crucible and ash does not change bymore than 0.2 mg after reheating at 925C for 30 min.10.1.2.3 BlankCarry a tare crucible with cover through alloperations in exactly the same manner as the crucibles con-taining specimens, as a check on possible loss
23、of mass of thecrucibles themselves.10.1.2.4 Test at least two specimens per sample.10.1.3 Calculation and ReportCalculate and report theash, corrected for the results of the blank test, to two significantfigures. Determine the weight percentage of the paper dried at105C.10.1.4 PrecisionDuplicate det
24、erminations shall agree asfollows:Ash, %Rounded toNearestReproducibility, %0.025 0.001 0.0030.025 to 0.01 0.005 0.010.1 0.01 0.0210.2 Retention of Precipitates:10.2.1 Apparatus:10.2.1.1 Glass Funnels, 60, having stems about 6 in. long.10.2.2 Reagents:10.2.2.1 Alcohol (95 %)Ethanol or formula No. 30.
25、10.2.2.2 Ammonium HydroxideAdd one part, by volume,of cp ammonium hydroxide (NH4OH) to one part by volumeof distilled water.10.2.2.3 Barium Chloride Solution (50 g/L)Dissolve 58.5g of cp barium chloride (BaCl22H2O) in distilled water anddilute to 1 L.10.2.2.4 Ferric Chloride SolutionDissolve 10 part
26、s byweight of cp ferric chloride (FeCl36H2O) in 100 mL ofdistilled water.10.2.2.5 Hydrochloric Acid (sp gr 1.19).10.2.2.6 Lead Acetate, cp anhydrous.10.2.2.7 Potassium Sulfate (K2SO4) cp.10.2.2.8 Sulfuric Acid (6 N).10.2.3 Procedure:10.2.3.1 Determine retention of precipitates by examiningthe filtra
27、te from freshly prepared suspensions of ferrichydroxide, lead sulfate, or barium sulfate, after filteringthrough specimens of the filter paper under test. To examine thefiltrate, swirl it in the flask to collect any precipitate present inthe center of the bottom of the flask, and then view the filtr
28、atefrom above against a black background. In this manner 0.3 mgTABLE 1 General RequirementsProperty Requirementalphacellulose content, min, % 95pH value 5.0 to 8.0TABLE 2 Wet Bursting StrengthClassWater Flow Rate and Retention of PrecipitatesWet BurstingStength min,aug pointsMaximumWater FlowRate,au
29、g, sRetention of Pre-cipitatesFiltrateClear from:AA 3.0 10 ferric hydroxideA 3.0 20 ferric hydroxideB 3.5 40 lead sulfateC 4.0 150 barium sulfateD 45.0 300 barium sulfateE 3.0 20 ferric hydroxideF 3.5 40 lead sulfateG 4.0 150 barium sulfateE832 81 (2013)2or less can be detected. Complete retention o
30、f fine precipitatesis indicated by the absence of visible barium sulfate (BaSO4)inthe filtrate.10.2.3.2 For Retention of Ferric HydroxideAdd a slightexcess of dilute NH4OH to the cold (room temperature) FeCl3solution and shake, then promptly filter the suspension throughone specimen of the filter pa
31、per under test, using a 60 funnel,into an Erlenmeyer flask, examine the filtrate as directed in10.2.3.1. Test at least four specimens per sample.10.2.3.3 For Retention of Lead SulfateDissolve 10 g oflead acetate in 100 mL of distilled water; filter through a filterpaper capable of retaining BaSO4. T
32、hen add 40 mL of 6 N H2SO4and 80 mL of alcohol. After the mixture has stood for 4 h,filter the suspension through one specimen of the filter paperunder test, in a 60 long-stemmed glass funnel into anErlenmeyer flask. Wash the precipitate and the precipitationflask with dilute H2SO4(5 mL of concentra
33、ted acid to 100 mLof distilled water). Then wash the precipitate on the paper withalcohol. Examine the filtrate as directed in 10.2.3.1. Test atleast four specimens per sample.10.2.3.4 For Retention of Barium SulfateDissolve 0.55 gof K2SO4in 275 mL of water and add 1.0 mL of HCl. Thisvolume of solut
34、ion contains the equivalent of about 0.1 g ofsulfur. Heat the solution to the boiling point and, when at thattemperature, add slowly and with continuous stirring 25 mL ofBaCl2(50 g/L). Let the mixture stand without agitation forfrom2to6hatatemperature between 70 and 100C.NOTE 1It is very important t
35、o have the specified acid concentrationand to keep the solution boiling during the precipitation.10.2.3.5 Fold four of the filter papers in the usual way forfiltration and place them in separate funnels. Stir the precipitatesuspension until the BaSO4is evenly distributed throughout theliquid. Then f
36、ilter about 50 mL through each cone of paper,collecting the filtrates in 250-mL Erlenmeyer flasks. Examinethe filtrate in the flasks as directed in 10.2.3.1.10.3 Water Flow Rate:10.3.1 Apparatus:10.3.1.1 Glass Funnel, 60.10.3.1.2 Buret, 50-mL.10.3.2 Procedure:10.3.2.1 Use distilled water that has be
37、en prefiltered throughthe test paper or through an 0.45-m membrane. Prepare threeof four times as much water as is necessary to fill the foldedpaper cones to be tested.10.3.2.2 Carefully fold a circle of the filter paper in theusual way, to form a 60 cone, having a diameter of 11 cm.Place it in a 60
38、 glass funnel and fill it with the prefilteredwater. Press down the folds to expel all air pockets and to makethe three plies smooth and in good contact. Allow about threefourths of the water to filter, then pour off the excess, saving thewater to wet other test specimens. Remove the wet paper conef
39、rom the funnel and suspend it freely over the buret bysupporting the cone in a wire loop of such diameter that itsupports the cone at about two thirds of the distance from theapex to the rim.10.3.2.3 Using prefiltered water having a temperature of 236 2C, pour into the cone, all at once, a known vol
40、ume that isapproximately two thirds of the volume of the cone. When onefifth of the water has filtered through into the buret, start a stopwatch. When half the remaining volume has filtered through,stop the stop watch and record the time in seconds. Test at least10 circles, using the same water over
41、 and over and adding itfrom the prepared supply as found necessary.NOTE 2Asuitable volume of water initially poured in, for filter circles11 cm in diameter, is 25 mL.10.3.2.4 The time required to filter half the volume of waterremaining in the conical filter is substantially the same for anygiven pa
42、per, irrespective of the size of the test specimen.10.3.3 ReportReport the filtration time in seconds andstate the diameter in centimetres of the filter paper used for thetest.10.4 Wet Bursting Strength:10.4.1 Procedure Clip together a pack of five squares (64mm by 64 mm) of the filter paper, and im
43、merse the pack indistilled water at 23 6 2C for 5 min. Remove the pack fromthe water, and allow it to drain while suspended for 10 s. Thenimmediately measure the bursting strength of the wet pack ina Mullen tester that conforms with the requirements of MethodD774/D774M, test for bursting strength of
44、 paper. Test at leastfive and preferably ten packs.10.4.2 ReportThe report shall state the number of testsmade, and the average, maximum, and minimum test results.11. Visual Inspection11.1 Circles from each package of the sample shall beinspected visually for compliance with Section 3.12. Ascertaini
45、ng Compliance with Specification12.1 The data generated through performance of the testmethods outlined in Section 9 shall be compared with Table 1and Table 2 to determine compliance.13. Keywords13.1 filter; laboratory; papersE832 81 (2013)3ASTM International takes no position respecting the validit
46、y 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 patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject
47、 to revision at any time by the responsible technical committee and must be reviewed every 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 Headquarter
48、s. Your comments will receive careful consideration at a meeting of theresponsible technical 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 i
49、s 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E832 81 (2013)4
