ASTM D5440-1993(2009) 781 Standard Test Method for Determining the Melting Point of Fats and Oils《测定脂肪和油熔点的标准试验方法》.pdf

1、Designation: D 5440 93 (Reapproved 2009)Standard Test Method forDetermining the Melting Point of Fats and Oils1This standard is issued under the fixed designation D 5440; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is intended to determine the meltingpoint of all normal animal and vegetable fats and oils. This test

3、method was derived from ALCA H-16.1.2 The values stated in SI units 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

4、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 American Leather Chemists Association Standard:ALCA H-16 Melting Point23. Significance and Use3.1 This test method is intended to

5、determine the meltingpoint of all normal animal and vegetable fats.3.2 The natural fats and oils, that is, those of animal andvegetable origin, are mixtures of glycerides and other sub-stances and consist of a number of components. They do notexhibit either a definite or sharp melting point. Fats pa

6、ssthrough a stage of gradual softening before they becomecompletely liquid. The melting point then shall be defined bythe specific conditions of the method by which it is determinedand, in this case, it shall be the temperature at which the samplebecomes perfectly clear and liquid.4. Apparatus4.1 Me

7、lting Point Tubes, capillary globe tubing, with aninside diameter of 1 mm and an outside diameter of 2 mm,max. A convenient length is 50 to 80 mm.4.2 Thermometer, 2 to 68C with 0.2C divisions.4.3 Glass Beaker, 600 mL.4.4 Heat Source, gas burner or electric hot plate.5. Procedure5.1 The sample shall

8、be melted and filtered through filterpaper to remove any impurities and the last traces of moisture.The sample shall be absolutely dry. At least three cleancapillary tubes shall be dipped in the completely liquid sampleso that the fat stands approximately 10 mm high in each tube.One end of the tube

9、(where the sample is located) shall befused in a small flame, taking care not to burn the fat.5.2 The tubes shall be placed in a beaker and held in arefrigerator at 4 to 10C overnight (16 h).5.2.1 The samples shall be completely liquid when the tubesare placed in the refrigerator. It is good practic

10、e to pass theends of the tubes containing the sample momentarily throughthe flame, just before they are taken to the refrigerator.5.3 After removing the tubes from the refrigerator, theyshall be attached to the thermometer, using a rubber band orany suitable means, so that the lower ends of the melt

11、ing pointtubes shall be even with the bottom of the mercury bulb of thethermometer. The thermometer shall be suspended in a 600 mLbeaker, which is about half full of clear distilled water and thebottom of the thermometer immersed approximately 30 mm.5.4 The starting bath temperature shall be adjuste

12、d to 8 to10C below the melting point of the sample at the beginning ofthe test. Agitation of the water bath shall be made with a smallstream of air or other suitable means, and heat shall be appliedso the batch temperature is increased at the rate of approxi-mately 0.5C per min.5.5 Fats usually pass

13、 through an opalescent stage beforemelting completely. The heating shall be continued until thetubes are completely clear throughout. The temperature shallbe observed at which each tube becomes clear.5.6 The average of the melting point of all the tubes shall betaken and this average shall be report

14、ed as the melting point.6. Report6.1 Report the temperature recorded in 5.6 as the meltingpoint in this test method.7. Precision and Bias7.1 This test method is adopted from the procedure of theAmerican Leather ChemistsAssociation where it has long beenin use, and where it was approved for publicati

15、on before theinclusion of precision and bias statements was mandated. The1This test method is under the jurisdiction ofASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.08 on Fats and OilsCurrent edition approved April 1, 2009. Published July 2009. Originallyapproved

16、in 1993. Last previous edition approved in 2003 as D 5440 93 (2003).2Available from American Leather Chemists Assn., Texas Tech University, P.O.Box 45300, Lubbock, TX 79409.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.original int

17、erlaboratory test data is no longer available. Theuser is cautioned to verify by the use of reference materials, ifavailable, that the precision and bias (or reproducibility) of thistest method is adequate for the contemplated use.8. Keywords8.1 fats and oils; leather; melting pointASTM Internationa

18、l 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 advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their o

19、wn 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 additional standardsand should be a

20、ddressed 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 the ASTM Committee on Standards,

21、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 5440 93 (2009)2