1、Designation: D 6403 99 (Reapproved 2004)Standard Test Method forDetermining Moisture in Raw and Spent Materials1This standard is issued under the fixed designation D 6403; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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 themoisture content in raw and spent materials that are extracte
3、dfor tannin analysis. The moisture content of the sample isoperationally defined to be equal to the weight loss experiencedas a result of the evaporation which occurs in the drying oven.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address
4、all of thesafety 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:2D 6405 Practice fo
5、r Extraction of Tannins from Raw andSpent Materials2.2 ALCA MethodsA6 Moisture in Raw and Spent Materials33. Terminology3.1 Definitions:3.1.1 raw materialany of the various parts of plants thatare used as a source of vegetable tannins.3.1.2 spent materialplant tissue by-products from indus-trial pro
6、cesses which may contain significant quantities ofvegetable tannins.3.1.3 tanninan astringent substance found in the variousparts of plants such as bark, wood, leaves, nuts, fruits, roots,etc.3.1.4 vegetable tanninsmixtures of substances (naturalproducts) obtained from plant tissues by water extract
7、ionwhich have the chemical and physical properties necessary toconvert animal hides and skins into leather.4. Summary of Test Method4.1 A specimen of the material sample prepared for use inPractice D 6405 is dried overnight in a forced-air oven. Theloss in weight represents the moisture in the speci
8、men.5. Significance and Use5.1 This test method is used to determine the moisturecontent of materials (raw or spent) that are to be extracted fortannin analysis. The value obtained for moisture content by thistest method is used to calculate the results of the other analyseson this material to a moi
9、sture-free basis.5.2 The specimens are obtained from the material preparedfor extraction in Practice D 6405.5.3 Tanning materials contain moisture in varying amounts,depending both on the nature of the material and on theclimatic conditions, therefore sampling must be carried out asquickly as is con
10、sistent with thoroughness in order to avoidchanges in moisture content.5.4 Negative errors may occur in the moisture determinationbecause under the conditions of this method there may beretention of moisture by certain components (for example,hydrated salts or water bound to organic structures) of t
11、he rawor spent material or because of oxidation of other components(for example, tannins) of the raw or spent material.5.5 Positive errors may occur in the moisture determinationbecause under the conditions of this test method there may bevolatilization of certain components of the raw or spentmater
12、ial other than water.5.6 It is known that other factors can also affect the quantityof volatile matter (moisture) released by the specimen. Thesefactors include but are not limited to: particle size of the test1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the dir
13、ect responsibility of Subcommittee D31.01 on Vegetable Leather. Thistest method has been adapted from and is a replacement for Method A6 of theOfficial Methods of the American Leather Chemists Association.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1999. Last pr
14、evious edition approved in 1999 as D 6403 99.2For 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.3Official Method
15、s of the American Leather Chemists Association. Availablefrom the American Leather Chemists Association, University of Cincinnati, P.O.Box 210014, Cincinnati, OH 45221-0014.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.specimen, qu
16、antity of test specimen, oven temperature, expo-sure time in the oven, shape of the specimen container, andtype of oven (for example, gravity or mechanical convection)used.5.7 Because of the possibility of unknown errors in this testmethod it is essential that the method be followed exactly inorder
17、to obtain reproducible results both among specimenswithin a laboratory and for analyses between laboratories.6. Apparatus6.1 Balance, analytical balance which will weigh up to 100g with an accuracy of 6 0.1 mg (6 0.0001 g).6.2 Tannin Dish, crystallizing dish, borosilicate glass, 50mm tall, 70 mm out
18、side diameter. The bottom corner 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.6.3 Watch Glass, a suitable size to be used as a cover for thetannin dishes. These can be used to keep dust and otherpossible cont
19、aminates from settling into the dishes whileexposed to the laboratory environment before and after thespecimen transfer operation. The watch glass covers must beremoved prior to placing the dishes in the drying oven.6.4 Drying Oven, a forced-air convection oven (ormechanical-convection draft oven) c
20、apable of maintaining atemperature of 100 6 2.0C.6.5 Thermometer, accurate to 6 0.2C which is used tocheck and monitor the oven set point.6.6 Dessicator, any convenient form or size, using anynormal dessicant.7. Test Specimen7.1 The specimen shall consist of approximately 10 g of thematerial from th
21、e sample prepared as described in the Prepa-ration of Sample and Test Specimens sections of PracticeD 6405.8. Procedure8.1 Preparation of Tannin Dishes:8.1.1 Place the clean, empty tannin dish in the oven at 1006 2.0C for at least 1 h.8.1.2 Remove the dish from the oven and place it in adessicator u
22、ntil it has reached temperature equilibrium with thelaboratory environment.8.1.3 Label the dish and record the weight as W1to thenearest 6 0.0001 g.8.1.4 Return the dish to the dessicator and store it there untilused.8.2 Specimen transfer:8.2.1 Transfer approximately 10 g of the material from thesam
23、ple prepared as described in Section 7 and Section 8 ofPractice D 6405 into the previously tared tannin dish preparedas above.8.2.2 Record the weight of the dish with the added materialas W2to the nearest 6 0.0001 g.NOTE 1Since the moisture content of many materials varies greatlydepending upon the
24、humidity of the surrounding environment, it isessential that all weighings be made rapidly. It is further recommendedthat no weighings of samples be carried out if the humidity of theatmosphere at the balance varies by more than 6 20 % from the humidityconditions under which the sample was equilibra
25、ted.8.3 Oven Drying:8.3.1 Place the tannin dish containing the test specimen ona shelf in the drying oven at 100 6 2.0C for 17 6 1h.8.3.2 Remove the dish from the oven and place it in adessicator until it has reached temperature equilibrium with thelaboratory environment.8.3.3 Record the weight of t
26、he dish with dried material asW3to the nearest 6 0.0001 g.9. Calculation9.1 Calculate the percent volatile matter (moisture) in thesample material as follows:moisture volatile matter!,%5 W22 W3!/W22 W1!# 3 100(1)where:W1= weight (grams), tare weight of tannin dish,W2= weight (grams), tannin dish plu
27、s original specimen,andW3= weight (grams), tannin dish plus oven-dried speci-men.9.2 Two specimens from each material sample shall betested. The average (mean) of the results from the twospecimens shall be taken as the moisture in the sample, exceptas described in 9.3.9.3 When the original material
28、was so wet that it had toreceive a preliminary drying before being ground in PracticeD 6405, the moisture content of the original material shall bedetermined as follows:9.3.1 The whole of the original, wet, sample shall beweighed. After drying as described in Practice D 6405, theweight of the partia
29、lly dried sample shall be determined. Themoisture loss in this preliminary drying shall be calculated asfollows:moisture loss preliminary drying step!,%5 WA2 WB!/WA!# 3 100(2)where:WA= weight (grams), the original wet sample, andWB= weight (grams), the partially dried sample.9.3.2 The residual moist
30、ure in the partially dried and finelyground sample shall be determined as described in Section 8and Section 9.9.3.3 Then the total moisture in the original, wet sampleshall be calculated as follows:total moisture original, wet sample!,%5 A 1 $B 3 100 2 A!/100%(3)where:A = (%) moisture loss (prelimin
31、ary drying step), andB = (%) residual moisture content in the partially driedsample.10. Report10.1 Report the moisture as percent volatile matter in thematerial to the nearest 0.01 %.D 6403 99 (2004)211. Precision and Bias11.1 This test method is adopted from Method A6 of TheOfficial Methods of the
32、ALCA. This test method has long beenin use and was approved for publication before the inclusion ofprecision and bias statements were mandated. The originalinter-laboratory test data is no longer available. The user iscautioned to verify by the use of reference materials, ifavailable, that the preci
33、sion and bias (or reproducibility) of thistest method is adequate for the contemplated use.11.2 The moisture content obtained by this test method isoperationally defined as the weight loss of the specimen afteroven drying. There is no independent measure of the moisturecontent of a sample. Therefore
34、 the bias cannot be related to thetrue moisture content of the sample.12. Keywords12.1 moisture; tannin analysis; vegetable tannin analysis;volatile matterASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.
35、 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 to revision at any time by the responsible technical committee and must be reviewed e
36、very 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 tec
37、hnical 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).D 6403 99 (2004)3
