1、Designation: D3861 91 (Reapproved 2003)Standard Test Method forQuantity of Water-Extractable Matter in Membrane Filters1This standard is issued under the fixed designation D3861; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 test method covers the gravimetric determinationof the water-extractable material present in membrane fil
3、tersand is applicable over the complete concentration range ofextractables.1.2 The analyst should be aware that adequate collaborativedata for precision and bias statements as required by PracticeD2777 is not provided. See Section 11 for details.1.3 This standard does not purport to address all of t
4、hesafety 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. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating
5、 to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on Water3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D1129.4. Summary of Test Method4.1 The quantity
6、of water-soluble extractables present inmembrane filters is determined by immersing the preweighedmembrane in boiling reagent grade water for an extended time,then drying and reweighing the membrane. A control mem-brane is employed to eliminate weighing errors caused bybalance changes or changing mo
7、isture content of the mem-brane in the weighing procedures. Weight changes of thecontrol membrane are applied as a correction factor to theweight change of the test membrane filters.5. Significance and Use5.1 The presence of water-soluble extractables in membranefilters can create errors in test pro
8、cedures employing membranefilters. However, these errors can be eliminated or significantlyreduced if the quantity of water-soluble extractables of thespecific membrane is previously determined. Certain mem-brane filter uses require specifications of maximum water-soluble extractable levels. This te
9、st method is intended to be arapid test to determine the loss of water-soluble compoundssuch as plasticizers or wetting agents from filtration mem-branes. This test method is not designed to predetermine theperformance of a filter, but is significant in determining thepercent extractables of membran
10、es from different sources andlot variations from a single source.6. Apparatus6.1 Beaker, borosilicate glass, 300-mL capacity.6.2 Forceps, stainless steel, unserrated tips.6.3 Desiccator.6.4 Drying Oven, with thermostatic control.6.5 Analytical Balance, sensitivity 0.01 mg.6.6 a-Emitting Polonium Sou
11、rce3(to discharge staticcharge in balance).6.7 Humidity-Controlled Room or Hood, for balance.6.8 Evaporating Dishes, glass, having sides or other meansto keep test filters on the dish while drying.7. Reagents and Materials7.1 Purity of Water Unless otherwise indicated, refer-ences to water shall be
12、understood to mean Type III reagentwater conforming to Specification D1193.7.2 Membrane Filters, 47-mm diameter (same type as thoseunder test).8. Preparation of Apparatus and Materials8.1 Preparation of Samples and Apparatus:8.1.1 Select 47-mm diameter sample (Note 1) membranefilters for the test, a
13、nd label with water-resistant ink.NOTE 1Square or rectangular membrane of equivalent area (17.4 cm2) may be used.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition ap
14、proved June 15, 1991. Published December 1991. Originallyapproved in 1979. Last previous edition approved in 1991 as D3861 91. DOI:10.1520/D3861-91R09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStan
15、dards volume information, refer to the standards Document Summary page onthe ASTM website.3The “Staticmaster,” available from Nuclear Products Inc., El Monte, CA, hasbeen found suitable for this purpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-29
16、59, United States.8.1.2 To provide a “control filter,” select and label oneadditional 47-mm membrane filter of the same type as thosebeing tested. Take the control filter through all the drying andweighing steps, but do not extract.8.1.3 Set drying oven at 70C.9. Procedure9.1 Heat the test and contr
17、ol filters in the oven at 70C for15 min.9.1.1 Remove filters from the oven and place them in thedesiccator for at least 30 min at room temperature.9.1.2 Remove filters from desiccator and place them inbalance room atmosphere for 10 to 15 min.9.1.3 In a humidity-controlled balance room or hood, weigh
18、test filters and control filter to 0.1 mg. Employ a staticeliminator in the balance.9.1.3.1 Place the “control” filter in the desiccator.9.2 Heat 200 mLof the reagent grade water to boiling, inserttest membrane filters, and continue heating with mild boilingfor 30 min. No more than four membrane fil
19、ters should beextracted in a single beaker of water. If water level is reducedbeyond 50 % of original level, add water to bring volume tooriginal level.9.3 Remove the filters using unserrated flat-bladed forceps,place them on clean glass evaporating dishes, and dry them inthe oven at 70C for 60 6 10
20、 min.9.3.1 Remove the test filters from the oven and examinethem to determine that none of the filter material has broken offin the handling and extraction. If any filter has been damaged,discard it and select a replacement for test.9.4 Place the test filters in the desiccator with the controlfilter
21、 for 30-min minimum time.9.5 Place the filters in balance room or hood atmosphere for10 to 15 min. Then weigh test and control filters to 0.1 mg todetermine final weight.10. Calculation10.1 Determine weight change of the test filter by subtract-ing the final weight W2from the initial weight W1of the
22、 testfilter.10.2 Determine weight change of the control filter bysubtracting the initial weight W3from the final weight W4ofthe control filter.10.2.1 If the weight change of the control filter exceeds 2mg, the test should be rerun.10.3 Determine corrected weight change of the test filter byadding we
23、ight change of the control filter (W4 W3)totheweight change of the test filter.10.4 Determine percent extractables as follows:E 5W12 W2! 1 W42 W3!W13 100where:E = percent extractables,W1= initial weight of test filter,W2= final weight of test filter,W3= initial weight of control filter, andW4= final
24、 weight of control filter.11. Precision and BiasNOTE 2The range of percent extractables for the samples tested forthe round-robin test to determine precision was 1.06 to 3.09 % extract-ables.11.1 The precision and bias of this test method was basedupon five laboratories with five operators using mem
25、branefilters of three different micron ratings.11.1.1 Precision:11.1.1.1 The overall precision of this test method may beexpressed as follows:St5 0.54X 2 0.37where:St= overall precision, %, andX = concentration of water extractables.11.1.1.2 The single-operator precision may be expressed asfollows:S
26、o5 0.64X 2 0.61where:So= single-operator precision, %, andX = concentration of water extractables.11.1.2 BiasMicroporous membranes are inherently vari-able and therefore no true or absolute value can be established.A bias statement is not applicable to this procedure.12. Keywords12.1 extractable; fi
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28、ch 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 years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for addi
29、tional standardsand should be addressed to ASTM International Headquarters. 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 th
30、e 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3861 91 (2003)2
