1、,ASTM D2608 84 0757530 O026273 O Designation:O 2608-84 4 T b AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race St.Philadelphia,Pa.49103 Reprinted from the Annual Book of ASTM Standards.Copyright ASTM If not listed in the current combined index,will appear in the next edition.Standard Test Method
2、for COPPER IN ELECTRICAL INSULATING OILS BY PHOTOMETRIC ANALYSIS This standard is issued under the fixed designation D 2608;the number immediately following the designation indicates the year of original adoptiomor,in the case of revision,the year of last revision.A number i n parentheses indicates
3、the year of last reapproval.A superscript epsilon(e)indicates an editorialchange since the last revision or reapproval.1.Scope.1.1 This test method covers the determination of copper in insulating oil in concentrations of O.1 ppm or greater.1.2 This standard may involve hazardous ma-terials,operatio
4、ns,and equipment.This standard does not purport to address all o f the safetyprob-lems associated with its use.It is the responsibil-ity of whoever uses this standard to consult and establish appropriate safety and health practices and determine the appkability o f regulatory limi-tations prior to u
5、se.2.Summary of Method 2.1 A 1+1 mixture of oil and hexane is ex-tracted with a 2+8 combination of hydrochloric and glacial acetic acids.The copper is concen-trated in the acid phase,which is then washed free of organic colored material with chloroform.Copper is determined colorimetrically as the ne
6、o-cuproine complex at approximately 450 nm.Since interfering organic substances in the visible range have been removed a simple colorimeter with a blue fiiter is adequate.3.Significance and Use 3.1 Electrical insulatingoil may contain smd amounts of dissolved metals derived either di-rectly from the
7、 base oil or from contact with metais during refining or service.4.Apparatus 4.1 Spectrophotometer or filter photometer with a blue filter capable of producing light of 450-nm wavelength.5.Reagents 5.1 Purity of Reagents-Reagent grade chem-icals shail be used in all tests.Unless otherwise indicated,
8、it is intended that aii reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemi-cal Society,where such specifications are avail-able.Other grades may be used,provided it is first ascertained that the reagent is of sufficiently high purity to permit
9、its use without lessening the accuracy of the determination.5.2 Purity$Water-Ali water shall be sufi-ciently deionized to give no color reaction with neocuproine reagent.:5.3 Acetic Acid,Glacial.5.4 Acetic-Hydrochloric Acid Mixture-Add slowly while stirring 200 mL of concentrated HC1(sp gr 1.19)to 8
10、00 mL of glacial acetic acid.5.5 Chloroform.5.6 Copper,Standard Solution(I mL=0.010 mg Cu)-Dissolve 0.2000 g of pure copper metal(99.9%copper)i n 10 mL of concentrated nitric acid(Dio3,sp gr 1.42).Add 5 mL of concen-trated sulfuric acid(H2S04,sp gr 1.84)and heat to white fumes.Allow to cool and tran
11、sfer quan-titatively to a 1-L volumetric flask containing 200 to 300 mL of distilled water and dilute to lo00 mL.Dilute a 50 mL aliquot of this solution to 1 L;1 mL of the resulting solution wiii contain 0.010 mg of copper.This test method is under the jurisdiction of ASTM Com-mittee D-27 on Electri
12、cal Insulating Liquids and Gases and is the direct responsibility of Subcommittee D27.06 on Chemical Test.Current edition approved July 27,1984.Published Septem-ber 1984.Originally published as D 2608-67.Last previous edition D 2608-70(1 979).Reagent Chemicals,American Chemical society Specifi-catio
13、ns,Am.Chemical Soc.,Washington,DC.For suggestions on the testing of reagents not listed by the American Chemical Society,see Reagent Chemicals and Standards,by Joseph Rosin,D.Van Nostrand Co.,Inc.,New York,NY,and the United States Pharmacopeia NOTICE:This standard has either been superseded and repl
14、aced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.ASTM D2b08 84 9 0759530 002b274 2 9 5.8 Hexane-Technical grade may be used.5.9 Hydrochloric Acid(sp gr 1.19)-Concen-trated hydrochloric acid(HCI).5.1 O Hydroxylamine Hydrochloride Solution(I O 0
15、g/L)-Dissolve 10 g of hydroxylamine hy-drochloride(NH20H.HCI)in 100 mL of water.5.1 1 Neocuproine Solution(I g/L)-Dissolve O.1 g of neocuproine3 2.9-dimethyI-1,lO-phen-anthroline in 100 mL of 2-propanol.5.12 Nitric Acid(sp gr 1.42)-Concentrated nitric acid(O3).5.13 2-Propanol.5.14 Sodium Hydroxide S
16、olution(200 g/L)-Dissolve 200 g of sodium hydroxide(NaOH)in water and dilute to 1 L.5.15 Sulfuric Acid(spgr I.?+Concentrated sulfuric acid(H2SO4).6.Preparation of Apparatus HNOa(l+l)and finally with distilled water.7.Preparation of Calibration Curve 7.1 Pipet O,1.0,2.0,4.0,6.0,8.0,and 10.0 mL of standard copper solution(1 mL=0.010 mg Cu)into a separatory funnel and follow pro-cedure for determinations of copper in oil siart-ing with 8.1 using the same reagents with the exception of oil.Plot the
