1、Designation: D1982 13Standard Test Method forTiter of Fatty Acids1This standard is issued under the fixed designation D1982; 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 parentheses indicat
2、es 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 determination of the solidi-fication (titer) point of fatty acids and is applicable to all fattyacids.1.2 The values stated in SI units
3、are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 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 standard to establish appro-priate safety and health practic
4、es and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1 Specification for ASTM Liquid-in-Glass Thermometers2.2 AOCS Standard:3Specification H 6-403. Significance and Use3.1 Saturated fatty acids solidify at a higher temperaturethan uns
5、aturated fatty acids. This test method provides a meansof measuring the solidification temperature of a sample con-taining 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
6、 acids willhave a higher titer (solidification temperature) than those withlower levels of saturated acids.3.3 Water present 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, wid
7、e-mouth, 450-mL capacity, 190-mm height,inside diameter of neck 40 mm.4.3 Test Tubes, 100 mm in length, 25 mm in diameter, 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 S
8、tirrer, 2 to 3 mm in outside diameter, with one end bentin the form of a loop 20 mm in outside diameter. Glass orstainless 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
9、.4.6 Titer Test ThermometerAn ASTM Titer Test Ther-mometer having a range from 2 to +68C and conforming tothe requirements for Thermometer 36C as prescribed in Speci-fication E1. Thermometric devices such as RTDs, thermistorsand liquid-in-glass thermometers of equal or better accuracy inthe specifie
10、d temperature range, may be used.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 (see 4.3) to a height of 57 m
11、mfrom 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 the water bath to the desig
12、nated 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 ofthe tube.1This test method
13、 is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.34 on Pine Chemicals and Hydrocarbon Resins.Current edition approved Nov. 1, 2013. Published December 2013. Originallyapproved in 1961. Last
14、previous edition approved in 2009 as D1982 85 (2009).DOI: 10.1520/D1982-13.2For 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
15、 ASTM website.3Available from American Oil Chemists Society (AOCS), 2710 S. Boulder,Urbana, IL 618026996, http:/www.aocs.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.4 Stir with the stirring rod through a vertical distance of
16、about 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 smallmotor with suitable speed-reducing mechanism to the stirring rod.5.5 Stir at
17、 the specified rate until the temperature remainsconstant for 30 s or begins to rise in less than a 30-s interval.Discontinue stirring 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 theth
18、ermometer during this rise.6. Precision and Bias6.1 PrecisionDuplicate determinations by the same opera-tor should agree within 0.2C.6.2 BiasBias has not been determined.7. Keywords7.1 fatty acids; saturated fatty acids; solidification point;titerASTM International takes no position respecting the v
19、alidity 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 s
20、ubject 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 Headq
21、uarters. 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 stan
22、dard 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/).FIG. 1 Apparatus Assembly for Titer TestD1982 132
