1、Designation: D 4903 99 (Reapproved 2004)Standard Test Method forTotal Solids and Water in Vegetable Tanning MaterialExtracts1This standard is issued under the fixed designation D 4903; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is intended for use in determining thetotal solids and water in extracts of vegetable
3、tanning materi-als. The test method is applicable to solutions of liquid, solid,pasty, and powdered extracts and to extracts of raw or spentmaterials.1.2 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
4、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:2D 4901 Practice for Preparation of Solution of Liquid Veg-etable Tannin ExtractsD 4902 Practice for Evaporation and Drying
5、 of AnalyticalSolutionsD 4905 Practice for Preparation of Solution of Solid, Pastyand Powdered Vegetable Tannin ExtractsD 6401 Test Method for Determining Non-Tannins andTannin in Extracts of Vegetable Tanning MaterialsD 6402 Test Methods for Determining Soluble Solids andInsolubles in Extracts of V
6、egetable Tanning MaterialsD 6404 Practice for Sampling of Vegetable Materials Con-taining TanninD 6405 Practice for Extraction of Tannins from Raw andSpent Materials2.2 ALCA Methods:A20 Total Solids and Water33. Summary of Test Method3.1 An aliquot of the prepared analytical solution is pipettedinto
7、 an evaporating dish and evaporated to dryness in a forcedair oven.4. Significance and Use4.1 The test method is useful in determining the total solidsand water in analytical solutions.5. Apparatus5.1 Tannin DishCrystallizing dish, borosilicate glass, 50mm tall, 70 mm outside diameter. The bottom co
8、rner shall berounded to a radius of 6 mm, the bottom shall be flat and notcupped in the center, and the top edge shall be rounded andpolished.5.2 Pipet, 100-mL capacity, preferably with a wide orificeapproximately 2.4 mm (332 in.) diameter and 15 to 25-sdelivery time.5.3 Drying OvenA forced-air conv
9、ection oven (ormechanical-convection draft oven) capable of maintaining atemperature of 100 6 2.0 C.5.4 ThermometerAccurate to 6 2.0 C, used to check andmonitor the oven set point.5.5 DessicatorAny convenient form or size.6. Test Specimen6.1 The specimen shall consist of 100 mL of a solutionprepared
10、 as described in Practices D 4901, D 4905, andD 6405.7. Procedure7.1 Thoroughly mix the solution, prepared as described inPractices D 4901, D 4905, and D 6405, by inverting andshaking 8 to 10 times, taking care to ensure that all insolublematter is uniformly dispersed and none left adhering to thewa
11、lls of the flask. Immediately, pour a 150-mL to 250-mLportion (approximately) into a bottle or other suitable con-tainer, stoppered or covered, and retain until the soluble solidsand non-tannins are ready to be pipetted (see Practice D 6404).Where the analysis is being performed in a constant temper
12、a-ture room, however, the specimen may be pipetted from thisportion at any convenient time. At the proper time, thoroughly1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. Thistest method has been
13、 adapted from and is a replacement for Method A20 of theOfficial Methods of the American Leather Chemists Association.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1989. Last previous edition approved in 1999 as D 490399.2For referenced ASTM standards, visit the A
14、STM 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.3Official Methods of the American Leather Chemists Association. Availablefrom the American Leather Chemi
15、sts Association, University of Cincinnati, P.O.Box 210014, Cincinnati, OH 45221.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.mix this secondary portion by shaking, or stirring, so that theinsoluble matter is uniformly distributed
16、throughout the liquorand none remains adhering to the walls of the container.Immediately rinse the 100-mL pipet with the liquor rejectingthe rinsings. Then stir the liquor well avoiding production ofair bubbles and foam, and while stirring immerse the tip of therinsed pipet and fill pipet quickly by
17、 suction. Bring the level tothe mark as quickly as possible, and transfer the 100-mLspecimen into a tared evaporating dish. (Since tan liquors arevery liable to foam and since they may contain large amountsof rapid-settling insoluble matter, conduct the final mixing, soas to avoid foam formation. Fi
18、ll and bring the pipet to the markas quickly as possible.) Place the dish containing the specimen,together with the other dishes containing the specimens forsoluble solids and non-tannins (Test Methods D 6401 andD 6402), in the drying oven and evaporate and dry as specifiedin Practice D 4902.8. Resu
19、lts8.1 The amount of total solids in the sample shall becalculated as follows:total solids, %W22 W1! 3 10W33 100 (1)where:W1= is the tare of the evaporating dish,W2= is the weight of the dish plus dry residue, andW3= is the weight of the specimen used in 1000 mL of thesolution (Practices D 4901, D 4
20、905, and D 6405).8.2 Since two specimens of each sample were taken inpreparing the solutions (Practices D 4901, D 4905, andD 6405), two values for total solids will be obtained for eachextract or tanning material. The average of these shall be takenas the percentage of total solids in the sample und
21、er test.(Duplicates are considered to be in good agreement when thepercent total solids differ by no more than 0.2.)8.3 Record the results to the nearest 0.01 %.9. Water9.1 The amount of water in the sample shall be calculated asfollows:% water 5 100 % total solids (2)where:percent total solids is d
22、etermined as in 8.1.10. Precision and Bias10.1 This test method is adopted from the procedures of theAmerican Leather Chemists Association3where it has longbeen in use and where it was approved for publication beforethe inclusion of precision and bias statements were mandated.The original interlabor
23、atory test data is no longer available.The user is cautioned to verify by the use of referencematerials, if available, that the precision and bias of this testmethod is adequate for the contemplated use.10.2 The total solids content obtained by this test method isoperationally defined as the dried s
24、olids weight of the specimencollected after drying the specimen. The water content isdefined as the difference between 100% and the total solids ofthe sample. There is no independent measure of the true totalsolids and water content of a sample. Therefore the bias cannotbe related to the true total
25、solids or water content of the sample.11. Keywords11.1 solids; tannin analysis; total solids; vegetable tanninanalysis; waterASTM 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 ex
26、pressly 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 every five years andif not revi
27、sed, 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 technical committee, which you ma
28、y 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).D 4903 99 (2004)2
