1、Designation:D349510(Reapproved 2015)Standard Test Method forHexane Extraction of Leather1This standard is issued under the fixed designation D3495;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()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the quantitative extraction of alltypes
3、of leather with hexane.This test method does not applyto wet blue.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 th
4、eresponsibility 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:2D2813 Practice for Sampling Leather for Physical andChemical TestsD3790 Test Method for
5、 Volatile Matter(Moisture)ofLeather by Oven Drying3.Significance and Use3.1 This test method measures the amount of hexane-soluble lubricant present in all types of leather.Adequatelubrication prevents abrasion of leather fibers during flexing.This lubrication is generally obtained from the fat liqu
6、or addedat the tannery.Some lubrication is also obtained from naturalgrease produced during the life of the animal.4.Apparatus4.1 Analytical Balance.4.2 Soxhlet Apparatus,consisting of a boiling flask,extrac-tion tube,and condenser.4.3 Forced Circulating Air Oven,capable of maintaining thespecified
7、temperature.4.4 Electric Hot Plate.4.5 Extraction Thimbles,fat-free,cellulose,Alundum,orfritted.4.6 Absorbent Cotton,fat-free.4.7 Steam Bath.5.Reagent5.1 Hexane,ACS Reagent Grade conforming to the follow-ing requirements:5.1.1 Color(APHA)10 max.5.1.2 Density(g/mL)at 25C0.687 max.5.1.3 Boiling Range1
8、 to 95 mL,not more than 4.0C.5.1.4 Residue After Evaporation0.001%max.5.1.5 Acidity(as CH3COOH)To pass test(limit 0.002%).5.1.6 Sulfur Compounds(as S)0.005%max.5.1.7 ThiopheneTo pass test.NOTE1This reagent grade hexane is generally a mixture of severalisomers of hexane(C6H14),predominantly n-hexane
9、and methylcyclopen-tane(C6H12).6.Test Specimens6.1 The leather shall be sampled in accordance with MethodD2813.Leather test specimens shall be obtained from thecomposite sample prepared by random sampling,cutting,andmixing equal portions of leather representing the lot that isbeing analyzed.The well
10、-mixed leather pieces shall be groundin a mill(Wiley or equal)having a No.5(4-mm)sieve.Theground leather that passes through this 4-mm sieve shall bemixed well and used as the composite sample.7.Procedure7.1 Determine the moisture content of the composite samplefrom which the ground leather for hexa
11、ne extraction is taken inaccordance with Test Method D3790.Determine the weight ofthe ground leather taken from the composite sample formoisture content at the same time and under the same ambientconditions as the weight of the ground leather taken for hexaneextraction.1This test method is under the
12、 jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.06 on Chemical Analysis.Current edition approved Dec.1,2015.Published December 2015.Originallyapproved in 1976.Last previous edition approved in 2010 as D3495 10.DOI:10.1520/D3495-10R15.2For referenced
13、 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,
14、PA 19428-2959.United States1 7.2 Weigh 5 g of ground leather taken from the composite tothe nearest 0.001 g and record this value as W1.Loosely packthis material in an appropriately sized extraction thimble andcover with a pad of fat-free cotton.Place the loaded thimble inthe Soxhlet extraction tube
15、.Dry an extraction flask in an ovenfor 1 h at 100 6 2C,cool in a desiccator,and weigh to thenearest 0.001 g.Record this value as W2.Fill the flaskapproximately two-thirds full with hexane,assemble theapparatus,circulate the water through the condenser,and heatthe flask until the extraction of the le
16、ather has continued for aminimum of 50 cycles.If the Soxhlet drips continuouslyinstead of cycling,extract the leather for a minimum of 5 husing maximum heat.At the end of the extraction period,remove the flask containing the extraction solvent and drive offthe hexane.When 10 to 20 mL of hexane remain,heat gentlyon a steam bath until the odor of the solvent can no longer bedetected.Facilitate the removal of the hexane by utilizing avacuum or a gentle stream of filtered(oil-and water-free)air.Afte
