1、Designation: D6018 96 (Reapproved 2012)Standard Test Method forDetermining the Presence of Lead Salts in Leather1This standard is issued under the fixed designation D6018; 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers qualitativel
3、y determining thepresence of lead salts in leather.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 theresponsibi
4、lity 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 Federal Standard:Federal Test Standard No. 311, Method 6551 Lead Salts,Presence of23. Significance and Use3.1 Thi
5、s test method may indicate the presence of lead saltsin leather. Lead salts may be found in pigments used in leathermanufacture.4. Apparatus4.1 Muffle Furnace.4.2 Porcelain Crucible.5. Reagents5.1 Nitric Acid, 1:1 dilution (equal volumes of nitric acidand distilled water).5.2 Hydrochloric Acid, spec
6、ific gravity 1.19.5.3 Ammonium Acetate, 3N, (231 g of ammonium acetatedissolved in distilled water to make 1 L).5.4 Potassium Chromate, 5 % solution (50 g potassiumchromate dissolved in distilled water to make 1 L).6. Procedure6.1 Place about5gofthespecimen in a tared porcelaincrucible. Place the sp
7、ecimen in a cold muffle furnace orpre-carbonized over a burner prior to placing in a hot furnace.Gradually raise the temperature of the furnace to 600 6 25Cand maintain at this temperature for 60 min. Remove thecrucible and contents, cool in a desiccator, and weigh. Replacein the furnace at 600 6 25
8、C for 30 min and repeat theweighing procedure until a constant weight is obtained (60.01g). If it is difficult to obtain a constant weight, leach the residuewith hot distilled water and filter through an ashless filterpaper. Place the filter paper in the crucible and ash. Add thefiltrate to the cruc
9、ible and evaporate. Then put the crucibleback in the muffle furnace and heat, cool, and weigh as aboveuntil a constant weight (60.01 g) has been obtained.6.2 After the crucible containing the ash has cooled, add 5mL of nitric acid (1:1) and carefully evaporate the mixture todryness. Then add 1 mL of
10、 concentrated hydrochloric acid andevaporate to dryness. Then add 5 mL of distilled water andevaporate to dryness. Add 10 mL of hot distilled water, filter,and wash the residue twice with 5 mL portions of hot 3Nammonium acetate collecting all the washings. Heat the filtrateslightly and add a few dro
11、ps of concentrated hydrochloric acidfollowed by a few drops of 5 % potassium chromate. Theformation of a yellow precipitate of lead chromate indicates thepresence of lead.7. Report7.1 Report the presence or absence of lead.8. Precision and Bias8.1 This test method is adopted from Federal Test Standa
12、rdNo. 311, Method 6551 where it has long been in use and wasapproved for publication before the inclusion of precision andbias statements was mandated. The user is cautioned to verifyby the use of reference materials, if available, that the precision1This test method is under the jurisdiction of AST
13、M Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.06 on Chemical Analysis. Thistest method was developed from Federal Test Method Standard No. 311,Method 6551 in cooperation with the U.S. Army Natick Research Development &Engineering Center, Natick MA and the Defense Per
14、sonnel Support CenterDirectorate of Clothing and Textiles, Philadelphia PA.Current edition approved April 1, 2012. Published April 2012. Originallyapproved in 1996. Last previous edition approved in 2006 as D6018 - 96(2006).DOI: 10.1520/D6018-96R12.2Available from Superintendent of Documents, U.S. G
15、overnment PrintingOffice, Washington, DC 20402.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for th
16、e latest information1and bias (or reproducibility) of this test method is adequate forthe contemplated use.9. Keywords9.1 lead; lead chromate; lead salts; leatherASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this st
17、andard. 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 own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be rev
18、iewed 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 addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsi
19、ble 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, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
20、onshohocken, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D6018 96 (2012)2
