1、Designation: D7674 10D7674 14Standard 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 la
2、st 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 covers the quantitative extraction of all types of wet blue and wet white with hexane or petroleum ethe
3、r.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establis
4、h appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For a specific hazard statement, see Section 7.2. Referenced Documents2.1 ASTM Standards:2D3495 Test Method for Hexane Extraction of LeatherD6658 Test Method for Volatile Matter (Moisture
5、) of Wet Blue by Oven DryingD6659 Practice for Sampling and Preparation of Wet Blue for Physical and Chemical TestsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods3. Summary of
6、Test Method3.1 A specimen is analyzed as received in wet state, diced; or pre-dried at the determined setting then ground prior to analysis.The prepared specimen is extracted with solvent. Another specimen from the same sample is also analyzed for moisture contentin accordance with Test Method D6658
7、. Following completion of the extraction process, the extract is dried, then cooled andweighed. The extract is reported as extractables 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 and we
8、t white.5. Apparatus5.1 Analytical Balance.5.2 Extraction ApparatusSoxhlet, consisting of a boiling flask, extraction tube, and condenser. Alternate ExtractionApparatus: Soxtec-type system consisting of an extraction unit and a control unit.5.3 Forced Circulating Air Oven, capable of maintaining the
9、 specified temperature.5.4 Electric Hot Plate (or steam bath).5.5 Extraction Thimbles, fat-free: cellulose, Alundum, glass microfiber, 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.1 Thi
10、s test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.02 on Wet Blue.Current edition approved Nov. 1, 2010April 1, 2014. Published December 2010June 2014. DOI: 10.1520/D7674-10.10.1520/D7674-14.2 For referencedASTM standards, vi
11、sit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM stand
12、ard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM
13、 is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17. Hazards7.1 All reagents and chemicals should be handled with care. Before using any chemical, read and follow all safety precautionsand inst
14、ructions on the manufacturers label or MSDS (Material Safety Data Sheet).8. Sampling8.1 The wet blue or wet white shall be sampled in accordance with Test Method D6659.9. ProcedureNOTE 1Two sample conditions are listed below. Both sample conditions produce acceptable results (See Precision and Bias
15、section).9.1 Condition AAs received in wet state, diced (prepared per Test Method D6659 Method A).9.1.1 Weigh out specimen for both moisture and hexane/petroleum ether extraction at the same time. For the hexane/petroleumether extraction, weigh an 8-10 g specimen to the nearest 0.001g and record thi
16、s value as W1. Loosely pack the material in anappropriately sized extraction thimble and cover with a pad of fat-free cotton or glass wool. Proceed with extraction using eitherthe Soxhlet apparatus or the Soxtec-type apparatus.9.1.2 Determine the moisture content of the prepared sample from which th
17、e specimen for extraction is taken (9.1.1) inaccordance with Test Method D6658.NOTE 2The cubed specimen weighed out for extraction may be air-dried overnight, prior to extraction.9.2 Condition BOven or air dried, ground (prepared per Test Method D6659 Method B).9.2.1 Weigh a 4-5 g specimen to the ne
18、arest 0.001g and record this value as W1. Loosely pack the material in an appropriatelysized extraction thimble and cover with a pad of fat-free cotton or glass wool. Proceed with extraction using either the Soxhletapparatus or the Soxtec-type apparatus.9.2.2 Determine the residual moisture content
19、of the prepared sample from which the specimen for extraction is taken inaccordance with Test Method D6658.9.3 Soxhlet ApparatusPlace the loaded thimble in the Soxhlet extraction tube. Dry an extraction flask in an oven for at least1 h at 100 6 2C (212 6 3.6F) to remove residual moisture. Cool in a
20、desiccator, and weigh to the nearest 0.001 g. Record thisvalue asW2. Fill the flask approximately two-thirds full with hexane or petroleum ether, assemble the apparatus, circulate the waterthrough the condenser, and heat the flask until the extraction of the sample has continued for a minimum of 50
21、cycles. If the Soxhletdrips continuously instead of cycling, extract the sample for a minimum of 5 h at that setting. At the end of the extraction period,remove the flask containing the extraction solvent and drive off the solvent. When 10 to 20 mL of solvent remain, heat gently ona steam bath until
22、 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 the solvent has been removed, dry the flask containing the extracted matterin a forced circulating air oven at 100 6 2C (212 6 3.6
23、F) for 1 h. Cool to room temperature in a desiccator and weigh. Continuedrying for successive 1-h periods at 100 6 2C (212 6 3.6F) until constant weight is obtained. When successive weighings varyby less than 60.005 g, consider the weight constant. Record this weight to the nearest 0.001 g as W3. If
24、 constant weight has notbeen obtained after the third drying, record that weight as the final weight.9.4 Soxtec-Type ApparatusDry an extraction cup in an oven for at least 1 h at 100 6 2C (212 6 3.6F) or 25-30 min at 1256 1C (257 6 1.8F) to remove residual moisture. Cool in a desiccator, and weigh t
25、o the nearest 0.001g. Record this value as W2.Circulate water through the condensers. Turn on the service unit and set the temperature control at 90 6 1C (194 6 1.8F). Fillthe cup approximately two-thirds full with petroleum ether or hexane. Place the loaded thimble in the Soxtec-type apparatus.Extr
26、act the sample by using the Soxtec-type boiling cycle for 45-50 min, followed by a rinse cycle of 45-50 min. After the rinsecycle, close the condenser and collect the solvent for 10-15 min. Open the Evaporation valve, press the Air button and pull airthrough the cups for 10-15 min. Close the Evapora
27、tion valve and release the extraction cups with the safety catch. Dry the cupsin a forced air circulating oven at 100 6 2C (212 6 3.6F) for 60-65 min or 25-30 min at 125 6 1C (257 6 1.8F). Cool thecups for 30-35 min (or to room temperature) in a desiccator. Continue drying for successive 15-min peri
28、ods until constant weightis obtained.When successive weighings vary by less than60.005 g, consider the weight constant. Record this weight to the nearest0.001 g as W3. If constant weight has not been obtained after the third drying, record that weight as the final weight.10. Calculation of Results10
29、.1 Calculate the percentage of hexane (or petroleum ether) extract, on a moisture-free basis, as follows:Hexane (or petroleum ether) extract =W32W2W131002%moisture!1003100 (1)where:W1 = weight of specimen, wet blue or wet white,W2 = weight of extraction flask,D7674 142W3 = weight of extraction flask
30、 and hexane (or petroleum ether) extract, and% moisture = moisture content of the sample from which the specimen was taken.11. Report11.1 Report the hexane (or petroleum ether) extract in the wet blue or wet white as the average value obtained from the testresults to the nearest 0.01 %.11.2 State th
31、at the results are calculated on a moisture-free basis.11.3 Report condition of the specimen (that is, Test Method D6659 Method A, or Test Method D6659 Method B).11.4 Report extraction apparatus used.12. Precision and Bias12.1 The precision of this test method is based on an interlaboratory study of
32、 WK15217, New Test Method forHexane/Petroleum Ether Extract in Wet Blue or Fats and Oils in Wet Blue, conducted in 2007. Seven laboratories tested the samematerial under five different test conditions using both an ether and a hexane extraction. Every “test result” represents an individualdeterminat
33、ion. Each laboratory was asked to submit two replicate test results, from a single operator, for each analysis andcondition. Except for the limited number of reporting laboratories, Practice E691 was followed for the design and analysis of thedata; the details are given in an ASTM Research Report.31
34、2.1.1 Repeatability limit (r)Two test results obtained within one laboratory shall be judged not equivalent if they differ bymore than the “r” value for that material; “r” is the interval representing the critical difference between two test results for the samematerial, obtained by the same operato
35、r using the same equipment on the same day in the same laboratory.12.1.1.1 Repeatability limits are listed in Table 1 and Table 2.12.1.2 Reproducibility limit (R)Two test results shall be judged not equivalent if they differ by more than the “R” value forthat material; “R” is the interval representi
36、ng the critical difference between two test results for the same material, obtained bydifferent operators using different equipment in different laboratories.12.1.3 The preceding terms (repeatability and reproducibility limit) are used as specified in Practice E177.12.1.4 Any judgment in accordance
37、with statements 12.1 and 12.1.2 would normally have an approximate 95 % probability ofbeing correct, however the precision statistics obtained in this ILS must not be treated as exact mathematical quantities which areapplicable to all circumstances and uses. The limited number of materials tested an
38、d laboratories reporting results guarantees thatthere will be times when differences greater than predicted by the ILS results will arise, sometimes with considerably greater orsmaller frequency than the 95 % probability limit would imply. The repeatability limit and the reproducibility limit should
39、 beconsidered as general guides, and the associated probability of 95 % as only a rough indicator of what can be expected.12.2 BiasAt the time of the study, there was no accepted reference material suitable for determining the bias for this testmethod, therefore no statement on bias is being made.12
40、.3 The precision statement was determined through statistical examination of the analytical results from seven laboratories,on one material under five different conditions. These conditions were described as the following:Condition A: Wet Blue, as-isCondition B: Wet Blue dried at 100C, for 1 hCondit
41、ion C: Wet Blue dried at 100C, for 2 hCondition D: Wet Blue air dried overnight, for 16 18 hCondition E: Wet Blue dried at 125C, for 4 h12.4 To judge the equivalency of two test results, it is recommended to choose the condition closest in characteristics to the testcondition.3 Supporting data have
42、been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR: D311013.TABLE 1 Hexane Extraction (%)ConditionsAverageAXRepeatabilityStandard DeviationsrReproducibilityStandardDeviationsRRepeatabilityLimitrReproducibilityLimitRA 0.683 0.199 0.057 0.203 0.161B 0.59
43、2 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 0.223A The average of the laboratories calculated averages.D7674 14312.5 The precision of this test method is based on an intralaboratoy study of ASTM WK40322, New Standard Test Method forthe Determination of Oil and G
44、rease in Wet Blue and Wet White, conducted between 2011 and 2013. Nine laboratories participatedin this study, testing 16 Wet Blue samples. Every “test result” represents an individual determination. The laboratories were askedto report a single test result for 13 materials and duplicate test result
45、s for 3 materials. Except for the absence of replicate test resultsfrom all of the study materials, Practice E691 was followed for the design and analysis of the data; the details are give in ASTMresearch reports.412.5.1 Repeatability (r)The difference between repetitive results obtained by the same
46、 operator in a given laboratory applyingthe same test method with the same apparatus under constant operating conditions on identical test material within short intervalsof time would in the long run, in the normal and correct operation of the test method, exceed the following values only in one cas
47、ein 20.12.5.1.1 Repeatability can be interpreted as maximum difference between two results, obtained under repeatability conditions,that is accepted as plausible due to random causes under normal and correct operation of the test method.12.5.1.2 Repeatability limits are listed in Table 3.12.5.2 Repr
48、oducibility (R)The difference between two single and independent results obtained by different operators applyingthe same test method in different laboratories using different apparatus on identical test material would, in the long run, in thenormal and correct operation of the test method, exceed t
49、he following values only in one case in 20.12.5.2.1 Reproducibility can be interpreted as maximum difference between two results, obtained under reproducibilityconditions, that is accepted as plausible due to random causes under normal and correct operation of the test method.12.5.2.2 Reproducibility limits are listed in Table 1.12.5.3 The above terms (repeatability limit and reproducibility limit) are used as specified in Practice E177.12.5.4 Any judgment in accordance with 12.5.1 would normally have an approximate 95 % probability of being c
