1、Designation:D 1342 92(Reapproved 2002)Standard Test Method forParaffin-Type Hydrocarbons in Carnauba Wax1This standard is issued under the fixed designation D 1342;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revi
2、sion.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 covers the determination,by chroma-tography,of paraffin-type hydrocarbons in carnauba wax.1.2 This standard does n
3、ot 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 ASTM Standards:D
4、 94 Test Method for Saponification Number of PetroleumProducts23.Significance and Use3.1 This test method is used to determine the natural oradded hydrocarbon component of carnauba.It is used forquality control or to assess adulteration.4.Apparatus4.1 Cylindrical Separatory Funnel,250-mL capacity,ha
5、v-ing an open top.4.2 Analytical Balance,having a sensitivity of 0.1 mg.4.3 Electric Hot Plate.4.4 Electric Oven,capable of maintaining a temperature of100 6 5C.5.Reagents5.1 Alumina,having an activity of II3according to theBrockmann classification.4Since alumina of an activity of Iaccording to the
6、classification also has been found to besatisfactory for the separation,any alumina falling in theactivity range from I to II is suitable for use in this test method.The alumina must be kept free from moisture to retain itsadsorptive properties.5.2 Heptane,technical grade.6.Procedure6.1 Place a wad
7、of glass wool in the bottom of theseparatory funnel and pour 220 to 225 g of alumina on top ofthis plug.Tap the side of the funnel sharply several times withthe palm of the hand in order to pack the alumina evenly,andthen cover the adsorbent with a thin layer of glass wool.Immediately warm the colum
8、n by pouring 400 mL of heptaneat its boiling point through the adsorbent with the stopcockadjusted to permit maximum flow of the solvent.Tap thecolumn to remove entrained air.Close the stopcock after thelast of the heptane has been added and while a layer about 10mm deep still remains above the surf
9、ace of the alumina.6.2 Dissolve 4.0 to 4.5 g of the sample,weighed to thenearest 0.01 g,in 700 mL of boiling heptane in a 1-L,tall-formbeaker.Pour the solution quantitatively onto the warm columnof alumina.Collect the percolate in a beaker placed under thefunnel with the stopcock in a position to pe
10、rmit maximum flowthrough the column.Maintain the temperature of the solutionbeing added and the column at approximately the boiling pointof heptane throughout the course of the addition.The tempera-ture of the percolate issuing from the funnel stem shall be at 50to 55C.After the last of the solution
11、 has been added,rinse thetall-form beaker with two successive 50-mL portions of fresh,boiling heptane and add the washings to the column.At thisstage a yellow band,which should not extend more than about40 mm down from the top of the alumina,will have developed.A wider band than this probably indica
12、tes that the column wasnot packed properly.In such a case it may be difficult to effecta clean separation of the hydrocarbons in one pass through thealumina.6.3 Elute the column with additional heptane at within 5Cof its boiling point and,when about 1 L of percolate has beenobtained,begin to test su
13、bsequent portions of the percolate forcomplete elution of the hydrocarbons.To do this,collect50-mL portions of the percolate in separate 100-mL beakers,evaporate the solvent on the hot plate,and allow the beakers tocool to room temperature.Elution of the paraffin-type hydro-carbons is complete when
14、no solids or only a trace of greasyresidue is obtained in one of these beakers.1This test method is under the jurisdiction ofASTM Committee D21 on Polishesand is the direct responsibility of Subcommittee D21.02 on Raw Materials.Current edition approved Aug.15,1992.Published October 1992.Originallypu
15、blished as D 1342 54 T.Last previous edition D 1342 82(1987).2Annual Book of ASTM Standards,Vol 05.01.3The F-20 grade furnished by the Aluminum Ore Co.,East St.Louis,Ill.,conforms to this requirement.4H.Brockmann and Hella Schodder,“Aluminiumoxyd mit Abgestuftem Ad-sorptions-vermgen zur Chromatograp
16、hischenAdsorption,”Berichte der DeutschenChemischen Gesellschaft,Vol 74,pp.7378.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.4 With the aid of warm heptane,transfer all residuesquantitatively from the small beakers to the main percolate,evaporate the solvent until the volume is 30 to 50 mL,and withthe aid of warm heptane,transfer the solution quantitatively toa beaker that has been weighed to the nearest 0.2 mg.Heat thebeaker on