ASTM D1982-1985(2004) Standard Test Method for Titer of Fatty Acids《脂肪酸凝固点标准试验方法》.pdf

1、Designation: D 1982 85 (Reapproved 2004)Standard Test Method forTiter of Fatty Acids1This standard is issued under the fixed designation D 1982; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in

2、 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 covers the determination of the solidi-fication (titer) point of fatty acids and is applicable to all fattyacids.1.2 This stan

3、dard does not purport to address 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 A

4、STM Standards:2E 1 Specification for ASTM Thermometers2.2 AOCS Standard:Specification H 64033. Significance and Use3.1 Saturated fatty acids solidify at a higher temperaturethan unsaturated fatty acids. This test method provides a meansof measuring the solidification temperature of a sample con-tain

5、ing both unsaturated and saturated fatty acids by coolingthe specimen and measuring the temperature at which solidi-fication occurs.3.2 Samples containing higher levels of saturated acids willhave a higher titer (solidification temperature) than those withlower levels of saturated acids.3.3 Water pr

6、esent in the sample will raise the titer, soprovisions are made in the test method to remove traces ofmoisture.4. Apparatus4.1 Beaker, Griffin low-form, 2-L capacity.4.2 Bottle, wide-mouth, 450-mL capacity, 190-mm height,inside diameter of neck 40 mm.4.3 Test Tubes, 100 mm in length, 25 mm in diamet

7、er, withor without rim. These tubes may have an etched markextending around the tube at a distance of 57 mm from thebottom to show the height to which the tube is to be filled.4.4 Stirrer, 2 to 3 mm in outside diameter, with one end bentin the form of a loop 20 mm in outside diameter. Glass orstainl

8、ess steel wire may be used. The upper end can be formedto accommodate hand stirring or to be attached to a mechanicalstirrer.4.5 Laboratory Thermometer, having a range from 0 to150C.4.6 Titer Test ThermometerAn ASTM Titer Test Ther-mometer having a range from 2 to + 68C and conforming tothe requirem

9、ents for Thermometer 36C as prescribed in Speci-fication E 1.NOTE 1Thermometers conforming to the requirements for the AOCSTiter Thermometer (AOCS Specification H 6-40) meet these require-ments.5. Procedure5.1 Heat the sample on a hot plate to 130C to remove tracesof moisture, and fill a test tube (

10、see 4.3) to a height of 57 mmfrom the bottom.5.1.1 Do not hold the sample at 130C nor reheat to thistemperature more than once. If excessive moisture is present,allow the water to settle, decant the fatty acids, and then refilterand reheat. The acids must be dry and free of suspended matter.5.2 Fill

11、 the water bath to the designated level (Fig. 1) andadjust the temperature to 15 to 20C below the expected titerpoint.5.3 Place the test tube containing the fatty acids in theassembly as shown in Fig. 1. Insert the titer thermometer to theimmersion mark so that it will be equidistant from the sides

12、ofthe tube.5.4 Stir with the stirring rod through a vertical distance ofabout 40 mm at the rate of 100 complete up-and-down motionsper minute (Note 2). Start the agitation while the temperatureis at least 10C above the titer point.NOTE 2Stirring may be performed mechanically by attaching a smallmoto

13、r with suitable speed-reducing mechanism to the stirring rod.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.34 on Naval Stores.Current edition approved June 1, 2004. Publi

14、shed June 2004. Originallyapproved in 1961, replacing Sections 79 of D 1467 59 T. Last previous editionapproved in 1999 as D 1982 85 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum

15、e information, refer to the standards Document Summary page onthe ASTM website.3Available from American Oil Chemists Society, 508 S. Sixth St., Champaign,IL 61820.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Copyright by ASTM Intl

16、 (all rights reserved); Mon Nov 3 21:17:04 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.5.5 Stir at the specified rate until the temperature remainsconstant for 30 s or begins to rise in less than a 30-s interval.Discontinue stirrin

17、g immediately, remove the stirrer or raise itout of the specimen, and observe the increase in temperature.The titer point is the highest temperature indicated by thethermometer during this rise.6. Precision and Bias6.1 PrecisionDuplicate determinations by the same op-erator should agree within 0.2C.

18、6.2 BiasBias has not been determined.7. Keywords7.1 fatty acids; saturated fatty acids; solidification point;titerASTM 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 expressly adv

19、ised 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 revised, either

20、 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 may attend. I

21、f 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. Indivi

22、dual 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).FIG. 1 Apparatus Assembly for Titer TestD 1982 85 (2004)2Copyright by ASTM Intl (all rights reserved); Mon Nov 3 21:17:04 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.