1、Designation: D7674 10Standard Test Method forHexane/Petroleum Ether Extract in Wet Blue and Wet White1This standard is issued under the fixed designation D7674; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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 covers the quantitative extraction of alltypes of wet blue and wet white with hexane or petroleumether.1.2 The
3、values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.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-priat
4、e safety and health practices and determine the applica-bility of regulatory limitations prior to use. For a specifichazard statement, see Section 7.2. Referenced Documents2.1 ASTM Standards:2D3495 Test Method for Hexane Extraction of LeatherD6658 Test Method for Volatile Matter (Moisture) of WetBlu
5、e by Oven DryingD6659 Practice for Sampling and Preparation of Wet Bluefor Physical and Chemical TestsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE177 Practice for Use of the Terms Precision and Bias inASTM Test Methods3. Summary of Test Method3.1
6、A specimen is analyzed as received in wet state, diced;or pre-dried at the determined setting then ground prior toanalysis. The prepared specimen is extracted with solvent.Another specimen from the same sample is also analyzed formoisture content in accordance with Test Method D6658.Following comple
7、tion of the extraction process, the extract isdried, then cooled and weighed. The extract is reported asextractables on a moisture-free basis.4. Significance and Use4.1 This test method measures the amount of solvent-soluble (hexane or petroleum ether) materials in wet blue andwet white.5. Apparatus
8、5.1 Analytical Balance.5.2 Extraction ApparatusSoxhlet, consisting of a boilingflask, extraction tube, and condenser. Alternate ExtractionApparatus: Soxtec-type system consisting of an extraction unitand a control unit.5.3 Forced Circulating Air Oven, capable of maintaining thespecified temperature.
9、5.4 Electric Hot Plate (or steam bath).5.5 Extraction Thimbles, fat-free: cellulose, Alundum, glassmicrofiber, or fritted glass.5.6 Absorbent Cotton, fat-free, or glass wool.6. Reagents and Materials6.1 Hexane, ACS Reagent Grade, or6.2 Petroleum Ether, ACS Reagent Grade.7. Hazards7.1 All reagents an
10、d chemicals should be handled with care.Before using any chemical, read and follow all safety precau-tions and instructions on the manufacturers label or MSDS(Material Safety Data Sheet).8. Sampling8.1 The wet blue or wet white shall be sampled in accor-dance with Test Method D6659.9. ProcedureNOTE
11、1Two sample conditions are listed below. Both sample condi-tions produce acceptable results (See Precision and Bias section).9.1 Condition AAs received in wet state, diced (preparedper Test Method D6659 Method A).1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the
12、direct responsibility of Subcommittee D31.02 on Wet Blue.Current edition approved Nov. 1, 2010. Published December 2010. DOI:10.1520/D7674-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vol
13、ume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.9.1.1 Weigh out specimen for both moisture and hexane/petroleum ether extraction at the same time. For t
14、he hexane/petroleum ether extraction, weigh an 8-10 g specimen to thenearest 0.001g and record this value as W1. Loosely pack thematerial in an appropriately sized extraction thimble and coverwith a pad of fat-free cotton or glass wool. Proceed withextraction using either the Soxhlet apparatus or th
15、e Soxtec-typeapparatus.9.1.2 Determine the moisture content of the preparedsample from which the specimen for extraction is taken (9.1.1)in accordance with Test Method D6658.NOTE 2The cubed specimen weighed out for extraction may beair-dried overnight, prior to extraction.9.2 Condition BOven or air
16、dried, ground (prepared perTest Method D6659 Method B).9.2.1 Weigh a 4-5 g specimen to the nearest 0.001g andrecord this value as W1. Loosely pack the material in anappropriately sized extraction thimble and cover with a pad offat-free cotton or glass wool. Proceed with extraction usingeither the So
17、xhlet apparatus or the Soxtec-type apparatus.9.2.2 Determine the residual moisture content of the pre-pared sample from which the specimen for extraction is takenin accordance with Test Method D6658.9.3 Soxhlet ApparatusPlace the loaded thimble in theSoxhlet extraction tube. Dry an extraction flask
18、in an oven forat least1hat1006 2C (212 6 3.6F) to remove residualmoisture. Cool in a desiccator, and weigh to the nearest 0.001g. Record this value as W2. Fill the flask approximatelytwo-thirds full with hexane or petroleum ether, assemble theapparatus, circulate the water through the condenser, and
19、 heatthe flask until the extraction of the sample has continued for aminimum of 50 cycles. If the Soxhlet drips continuouslyinstead of cycling, extract the sample for a minimum of5hatthat setting. At the end of the extraction period, remove theflask containing the extraction solvent and drive off th
20、e solvent.When 10 to 20 mL of solvent remain, heat gently on a steambath until the odor of the solvent can no longer be detected.Facilitate removal of the solvent by utilizing a vacuum or agentle stream of filtered (oil and water-free) air. After thesolvent has been removed, dry the flask containing
21、 the ex-tracted matter in a forced circulating air oven at 100 6 2C(212 6 3.6F) for 1 h. Cool to room temperature in a desiccatorand weigh. Continue drying for successive 1-h periods at 1006 2C (212 6 3.6F) until constant weight is obtained. Whensuccessive weighings vary by less than 60.005 g, consi
22、der theweight constant. Record this weight to the nearest 0.001 g asW3. If constant weight has not been obtained after the thirddrying, record that weight as the final weight.9.4 Soxtec-Type ApparatusDry an extraction cup in anoven for at least1hat1006 2C (212 6 3.6F) or 25-30 minat 125 6 1C (257 6
23、1.8F) to remove residual moisture. Coolin a desiccator, and weigh to the nearest 0.001g. Record thisvalue as W2. Circulate water through the condensers. Turn onthe service unit and set the temperature control at 90 6 1C(194 6 1.8F). Fill the cup approximately two-thirds full withpetroleum ether or h
24、exane. Place the loaded thimble in theSoxtec-type apparatus. Extract the sample by using the Soxtec-type boiling cycle for 45-50 min, followed by a rinse cycle of45-50 min. After the rinse cycle, close the condenser andcollect the solvent for 10-15 min. Open the Evaporation valve,press the Air butto
25、n and pull air through the cups for 10-15min. Close the Evaporation valve and release the extractioncups with the safety catch. Dry the cups in a forced aircirculating oven at 100 6 2C (212 6 3.6F) for 60-65 min or25-30 min at 125 6 1C (257 6 1.8F). Cool the cups for30-35 min (or to room temperature
26、) in a desiccator. Continuedrying for successive 15-min periods until constant weight isobtained. When successive weighings vary by less than60.005 g, consider the weight constant. Record this weight tothe nearest 0.001 g as W3. If constant weight has not beenobtained after the third drying, record
27、that weight as the finalweight.10. Calculation of Results10.1 Calculate the percentage of hexane (or petroleumether) extract, on a moisture-free basis, as follows:Hexane (or petroleum ether) extract =W3 2 W2W1 3100 2 % moisture!1003 100 (1)where:W1 = weight of specimen, wet blue or wet white,W2 = we
28、ight of extraction flask,W3 = weight of extraction flask and hexane (orpetroleum ether) extract, and% moisture = moisture content of the sample from whichthe specimen was taken.11. Report11.1 Report the hexane (or petroleum ether) extract in thewet blue or wet white as the average value obtained fro
29、m thetest results to the nearest 0.01 %.11.2 State that the results are calculated on a moisture-freebasis.11.3 Report condition of the specimen (that is, Test MethodD6659 Method A, or Test Method D6659 Method B).11.4 Report extraction apparatus used.12. Precision and Bias12.1 The precision of this
30、test method is based on aninterlaboratory study of WK15217, New Test Method forHexane/Petroleum Ether Extract in Wet Blue or Fats and Oilsin Wet Blue, conducted in 2007. Seven laboratories tested thesame material under five different test conditions using both anether and a hexane extraction. Every
31、“test result” represents anindividual determination. Each laboratory was asked to submittwo replicate test results, from a single operator, for eachanalysis and condition. Except for the limited number ofreporting laboratories, Practice E691 was followed for thedesign and analysis of the data; the d
32、etails are given in anASTM Research Report.33Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D311013.D7674 10212.1.1 Repeatability limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydif
33、fer by more than the “r” value for that material; “r”istheinterval representing the critical difference between two testresults for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory.12.1.1.1 Repeatability limits are listed in Table 1 and T
34、able2.12.1.2 Reproducibility limit (R)Two test results shall bejudged not equivalent if they differ by more than the “R” valuefor that material; “R” is the interval representing the criticaldifference between two test results for the same material,obtained by different operators using different equi
35、pment indifferent laboratories.12.1.3 The preceding terms (repeatability and reproducibil-ity limit) are used as specified in Practice E177.12.1.4 Any judgment in accordance with statements 12.1and 12.1.2 would normally have an approximate 95 % prob-ability of being correct, however the precision st
36、atistics ob-tained in this ILS must not be treated as exact mathematicalquantities which are applicable to all circumstances and uses.The limited number of materials tested and laboratories report-ing results guarantees that there will be times when differencesgreater than predicted by the ILS resul
37、ts will arise, sometimeswith considerably greater or smaller frequency than the 95 %probability limit would imply. The repeatability limit and thereproducibility limit should be considered as general guides,and the associated probability of 95 % as only a rough indicatorof what can be expected.12.2
38、BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod, therefore no statement on bias is being made.12.3 The precision statement was determined through sta-tistical examination of the analytical results from seven labo-ratories, o
39、n one material under five different conditions. Theseconditions were described as the following:Condition A: Wet Blue, as-isCondition B: Wet Blue dried at 100C, for 1 hCondition C: Wet Blue dried at 100C, for 2 hCondition D: Wet Blue air dried overnight, for 16 18 hCondition E: Wet Blue dried at 125
40、C, for 4 h12.4 To judge the equivalency of two test results, it isrecommended to choose the condition closest in characteristicsto the test condition.13. Keywords13.1 blue stock; extractables; extraction; fat; hexane; oil;petroleum ether; Soxhlet; Soxtec; wet blue; wet whiteTABLE 1 Hexane Extraction
41、 (%)ConditionsAverageAXRepeatabilityStandard DeviationsrReproducibilityStandardDeviationsRRepeatabilityLimitrReproducibilityLimitRA 0.683 0.199 0.057 0.203 0.161B 0.592 0.114 0.058 0.121 0.162C 0.574 0.104 0.056 0.111 0.157D 0.620 0.206 0.080 0.213 0.223AThe average of the laboratories calculated av
42、erages.D7674 103ASTM 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 advised that determination of the validity of any such patent rights, and the riskof infringement of
43、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 reapproved or withdrawn. Your comments are invited either for revision of this standard or for ad
44、ditional 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. If you feel that your comments have not received a fair hearing you shouldmake your views known to
45、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. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at t
46、he 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/).TABLE 2 Petroleum Ether Extraction (%)ConditionsAver
47、ageAXRepeatabilityStandard DeviationsrReproducibilityStandardDeviationsRRepeatabilityLimitrReproducibilityLimitRA 0.798 0.144 0.118 0.166 0.330B 0.447 0.167 0.008 0.168 0.023C 0.473 0.154 0.033 0.155 0.091D 0.487 0.121 0.041 0.124 0.114E 0.560 0.000 0.028 0.028 0.079AThe average of the laboratories calculated averages.D7674 104
