1、Designation: D1686 10Standard Test Method forColor of Solid Aromatic Hydrocarbons and Related Materialsin the Molten State (Platinum-Cobalt Scale)1This standard is issued under the fixed designation D1686; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the visual measurement of thecolor of thermally stable sol
3、ids melting below 150C. It isapplicable only to materials in which the color-producingbodies present have light absorption characteristics quite simi-lar to those of the standards used.1.2 In determining the conformance of the test results usingthis method to applicable specifications, results shall
4、 berounded off in accordance with the rounding-off method ofPractice E29.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its us
5、e. 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. For specific hazardstatements see Sections 7 and 9.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for
6、 Reagent WaterD3438 Practice for Sampling and Handling Naphthalene,Maleic Anhydride, and Phthalic AnhydrideD3852 Practice for Sampling and Handling Phenol,Cresols, and Cresylic AcidD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Pra
7、ctice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 Other Document:OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.120033. Significance and Use3.1 Color by this test method is a measure of color-producing impurities present in the thermally stable sol
8、ids.This test method is suitable for setting specifications and foruse as an internal quality control tool.4. Apparatus4.1 Color Comparison TubesMatched 100-mL, tall-formNessler tubes, provided with ground-on, optically clear, glasscaps. Tubes should be selected so that the height of the 100-mLgradu
9、ation mark is 300 6 3 mm above the bottom of the tube.The use of heat-resistant tubes is preferred for safety reasons.4.2 Color ComparatorA color comparator constructed topermit visual comparison of light transmitted through tall-form, 100-mL Nessler tubes in the direction of their longitu-dinal axe
10、s. The comparator should be constructed so that whitelight is reflected off a white plate and directed with equalintensity through the tubes, and should be shielded so that nolight enters the tubes from the side.4.3 OvenAn oven, preferably of the forced draft type andcapable of maintaining a constan
11、t temperature 61C in therange up to 150C. Alternatively, the use of an aluminumheating block provided with proper temperature control orother similar equipment is permissible.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the di
12、rect responsibility ofSubcommittee D16.02 on Oxygenated Aromatics.Current edition approved Jan. 1, 2010. Published January 2010. Originallyapproved in 1959. Last previous edition approved in 2004 as D1686 96 (2004).DOI: 10.1520/D1686-10.2For referenced ASTM standards, visit the ASTM website, www.ast
13、m.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.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washingt
14、on, DC 20401, http:/www.access.gpo.gov.TABLE 1 Platinum-Cobalt Color StandardsAColorStandardNo.StockSolution,mLColorStandardNo.StockSolution,mL5135 710 2 40 815 3 50 1020 4 60 1225 5 70 1430 6 100 20AOther color standards may be prepared by proportional dilution.1*A Summary of Changes section appear
15、s at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall confor
16、m to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the d
17、etermination.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type IV reagent waterconforming to Specification D1193.5.3 Cobalt Chloride (CoCl26H2O).5.4 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).5.5 Potassium Chloroplatinate (K2P
18、tCl6).6. Standards6.1 Platinum-Cobalt Stock Solution Dissolve 1.245 g ofK2PtCl6and 1.000 g of CoCl26H2O in water. Add 100 mL ofHCl and dilute to 1 L with water. This solution has a color of500.56.2 Platinum-Cobalt Standards6From the stock solution,prepare color standards, as given in Table 1, by dil
19、uting therequired volumes to 100 mL with water in the Nessler tubes. Ifdesired, these standards may be made permanent by sealing onthe caps with a suitable colorless cement.7. Hazards7.1 Consult OSHA regulations, suppliers Material SafetyData Sheets, and local regulations for all materials used in t
20、histest method.7.2 Warning: When handling molten solids in open tubes,adequate ventilation must be provided and proper protectionshould be used to prevent thermal burns.8. Sampling8.1 Sample the material in accordance with Practices D3438or D3852.9. Procedure9.1 Melt approximately 150 g of the sampl
21、e and simulta-neously preheat a Nessler tube and cap in an oven maintainedat constant temperature at 10 to 20C above the solidificationpoint of the sample. The sample must not be heated to morethan 20C above its solidification point.9.2 As soon as the sample is completely liquid, mix bystirring with
22、 a clean dry glass rod, then quickly fill thepreheated Nessler tube to the 100-mL mark with the sampleand cap the tube. Place the tube in the comparator andimmediately compare with the standards.NOTE 1Avariation of more than 2 to 3 mm in depth can affect the testresults.9.3 When measuring the color
23、of solids that sublime, somedifficulty may be encountered due to condensation of solid onthe cap. In such a case, the Nessler tube may be reheated in theoven after first loosening the cap, or, the color may bemeasured using an open Nessler tube without a cap (Warning,see 9.3.1). In this latter case
24、the caps should also be removedfrom the standards.9.3.1 Warning: Make sure to provide adequate ventilationif open tubes are used.9.4 In no case shall this test method be applied if the moltensample contains any visible turbidity.10. Report10.1 Report as the color, the number of the standard thatmost
25、 nearly matches the sample. In the event that the color liesmidway between two standards, report the darker of the two.10.2 If, owing to small differences in hue between thesample and the standards, an exact match cannot be obtained,but an estimate is possible, report the range over which anapproxim
26、ate match is obtained, and report the sample as “offhue.”10.3 If, owing to large differences in hue between thesample and the standards, no estimate is possible, report thesample as “no match.”11. Precision and Bias11.1 Intermediate Precision (formerly calledRepeatability)Results in the same laborat
27、ory should not beconsidered suspect unless they differ by more than the follow-ing amounts:Platinum-Cobalt Color Intermediate PrecisionUnder No. 50 2.5No. 50 to No. 100 5Over No. 100 1011.2 ReproducibilityResults submitted by two laborato-ries should not be considered suspect unless they differ bymo
28、re than the following amounts:Platinum-Cobalt Color ReproducibilityUnder No. 50 5No. 50 to No. 100 10Over No. 100 1511.3 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod, bias has not been determined.12. Quality Guidelines12.1 La
29、boratories shall have a quality control system inplace.12.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control practices.4Reagent Chemicals, American Chemical Society Specifications, Ame
30、ricanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (US
31、PC), Rockville,MD.5The stock solution with color No. 500 may be purchased as such from chemicalsupply firms. Use of the purchased standard is satisfactory.6The preparation of these platinum-cobalt standards was originally described byA. Hazen, American Chemical Journal, Vol 14, p. 300 (1892). The de
32、scriptiongiven in Test Method D1686 is identical with that given in the “Standard Methodsfor the Examination of Water and Sewage,” American Public Health Assn., TenthEdition, 1955, p. 88. A description is also given by W. W. Scott, “Standard Methodsof Chemical Analysis,” D. Van Nostrand Co., Inc., F
33、ifth Ed., Vol 2, p. 2048.D1686 10212.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.12.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the va
34、lidity of test results.12.1.4 When there are no QA/QC protocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.13. Keywords13.1 color; cresylic acid; maleic anhydride; naphthalene;phenol; phthalic anhydride; platinum-co
35、balt; solid aromatichydrocarbonsSUMMARY OF CHANGESCommittee D16 has identified the location of selected changes to this standard since the last issue(D1686 - 96 (2004) that may impact the use of this standard. (Approved January 1, 2010.)(1) Added Quality Guidelines Section 12.(2) Added statement on
36、units section 1.3.(3) Added Guide D6809 to list of Referenced Documents section 2.1.ASTM 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
37、 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 reviewed every five years andif not revised, either reapproved or withdrawn. Your
38、 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 theresponsible technical committee, which you may attend. If you feel that your comments
39、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 Conshohocken, PA 19428-2959,United States. Individual reprints (single or multi
40、ple 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/).D1686 103
