1、Designation:D84716Standard Test Method forAcidity of Benzene,Toluene,Xylenes,Solvent Naphthas,and Similar Industrial Aromatic Hydrocarbons1This standard is issued under the fixed designation D847;the number immediately following the designation indicates the year oforiginal adoption or,in the case o
2、f 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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This test meth
3、od is intended for the detection of acidityof benzene,toluene,xylenes,solvent naphthas,and similarindustrial aromatic hydrocarbons.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
4、all of thesafety concerns,if any,associated with its use.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 Section 9.2.Referenced Documen
5、ts2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid CyclicProducts2.2 Other Documents:OSHA Regulations,29CFR paragraphs 1910.1000 and1910.120033.Terminology3.1 Definitions:3.1.1 acidity,nfor purposes of this standard,acidity isdefined as produci
6、ng a persistent pink phenolphthalein endpoint with the addition of two(2)drops or more(0.1 mL)of 0.1N sodium hydroxide solution.3.1.2 acid reaction,na characteristic of materials produc-ing the acid-color of the indicator used under the conditionsprescribed in this test method.3.1.3 alkaline or basi
7、c reaction,na characteristic of thematerials producing the alkali-color of the indicator used underthe conditions prescribed in this test method.4.Summary of Test Method4.1 The acidity of aromatic hydrocarbons is detected usinga sodium hydroxide titration and a color change using aphenolphthalein in
8、dicator.5.Significance and Use5.1 This test method is suitable for setting specifications,foruse as an internal quality control tool,and for use in develop-ment or research work on industrial aromatic hydrocarbons andrelated materials.This test method gives an indication ofresidual acidity and is a
9、measure of the quality of the finishedproduct.It is an indication of the tendency of the product tocorrode equipment.6.Interferences6.1 Tests for acidity are not applicable in the presence ofcontaminating acidic or alkaline gases,soaps,salts,or othercompounds derived from the atmosphere or apparatus
10、.Thecontainer holding the specimen,and the apparatus,water,indicator,and other materials used in the test shall be chosen sothat they themselves shall not appreciably affect the results.Since new corks used in specimen bottles often are bleachedwith oxalic acid,it is advisable to rinse them thorough
11、ly andcheck them for neutrality with the indicator used in the test.Glassware shall be of acid-resistant and alkali-resistant glass4and shall be rinsed with neutral distilled water before use.Theroom in which the test is performed shall be chosen so as toprevent undue contamination by carbon dioxide
12、,ammonia,orother interfering substances that may be present in the atmo-sphere.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.01 on Benzene,Toluene,Xylenes,Cyclohexane and TheirDeriva
13、tives.Current edition approved June 1,2016.Published July 2016.Originally approvedin 1945.Last previous edition approved in 2015 as D847 15.DOI:10.1520/D0847-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of AS
14、TMStandards 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,Washington,DC 20401,http:/www.access.gpo.gov.4Borosilicate glass or the equivalent has been fou
15、nd satisfactory for this purpose.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 The distilled water used in the test shall not alter thecomposition of the specimen nor
16、otherwise interfere with thepurpose of the work.Although inert impurities often may beneglected,care must be exercised to correct for impurities or toeliminate them entirely if they are likely to interfere.When thedistilled water does not show an acid or alkaline reaction,itmay be used without further adjustment to neutrality.However,if the water shows an acid or alkaline reaction,it shall bebrought to a persistent pink end point before use by titrationwith standard 0.01 N NaOH solution(see 8.4)
