1、Designation:D354605(Reapproved 2011)Standard Test Method forFormic Acid in Glacial Acetic Acid1This standard is issued under the fixed designation D3546;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numb
2、er 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 determination of the formicacid(and other reducing substances)content of glacial aceticacid by oxidation with lead
3、 tetraacetate.21.2 For purposes of determining conformance of an ob-served or a calculated value using this test method to relevantspecifications,test result(s)shall be rounded off“to the nearestunit”in the last right-hand digit used in expressing thespecification limit,in accordance with the roundi
4、ng-off methodof Practice 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 For hazard information and guidance,see the suppliersMaterial Safety Data Sheets.1.5 This standard does not purport to address all of thesafety
5、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.2.Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterE2
6、9 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical Analysis3.Summary of Test Method3.1 In an aqueous acetic acid solution each molecule offormic acid i
7、s oxidized to one molecule of carbon dioxide byreduction of one molecule of lead tetraacetate.The amount oflead tetraacetate remaining is then determined by addingpotassium iodide and titrating the liberated iodine with stan-dard sodium thiosulfate solution to the starch end point.4.Significance and
8、 Use4.1 This test method is useful for determining the formicacid content of glacial acetic acid by chemical means.4.2 Low molecular weight organic acids(such as acetic andpropionic),aldehydes(including formaldehyde and acetalde-hyde),ketones,and alcohols(including methyl alcohol)do notinterfere wit
9、h the test.4.3 Formic acid(and other reducing substances)may bepresent as a result of contamination during storage,distribu-tion,and manufacture.This test method may be used inassessing compliance with a specification.5.Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.
10、Unless otherwise indicated it is intended thatall reagents shall conform 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 ofsufficientl
11、y high purity to permit its use without lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated referenceto water shall be understood to mean reagent water conformingto Type IV of Specification D1193.5.3 Lead Tetraacetate SolutionDissolve completely 40.0 gof sodium a
12、cetate in 1 L of glacial acetic acid and then dissolve40.0 g of lead tetraacetate.5.4 Sodium Thiosulfate Standard Solution(0.1 N)Prepareand standardize 0.1 N sodium thiosulfate(Na2S2O3)as de-scribed in Practice E200.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Relate
13、d Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.35 on Solvents,Plasticizers,and Chemical Intermediates.Current edition approved Feb.1,2011.Published February 2011.Originallyapproved in 1976.Last previous edition approved in 2005 as D3546 05.DOI:10.1520/D3546
14、-05R11.2Perlin,A.S.,“Determination of Formic Acid by Oxidation with LeadTetraacetate,”Analytical Chemistry,Vol 26,1954,pp.10531054.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information
15、,refer to the standards Document Summary page onthe ASTM website.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH L
16、td.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.*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 5.5 Starch Indicator SolutionPrepare the starch indicatorsolution as described in Practice E200.5.6 Stopping SolutionDissolve 100 g of potassium iodideand 500 g of sodium acetate in 1 L of wate