1、Designation: D 2180 89 (Reapproved 2008)Standard Test Method forActive Oxygen in Bleaching Compounds1This standard is issued under the fixed designation D 2180; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of inorganic“active oxygen” in bleaching compounds such as perborates,percarbonates, a
3、nd peroxides but not in persulfates or monop-ersulfates.1.2 This standard does not purport to address 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-bilit
4、y of regulatory limitations prior to use. Material SafetyData Sheets are available for reagents and materials. Reviewthem for hazards prior to usage.2. Referenced Documents2.1 ASTM Standards:2D 459 Terminology Relating to Soaps and Other DetergentsD 1193 Specification for Reagent Water3. Terminology
5、3.1 Definition:3.1.1 active oxygenthe measure of the oxidizing power ofcompounds such as inorganic perborates, percarbonates, orperoxides which, in effect, release hydrogen peroxide in acidsolutions. It is expressed in terms of oxygen (O) with gram-equivalent weight of 8.00.4. Summary of Test Method
6、4.1 Active oxygen is determined by titration of an acidifiedaqueous solution of the compound with a standard solution ofpotassium permanganate.NOTE 1Use of a molybdate-catalyzed iodometric method for thispurpose has been suggested, but the possible reaction of the liberatediodine on organics present
7、 must be considered. It is believed there is lesslikelihood of reaction with permanganate, provided the titration isperformed in such a manner as to avoid any considerable excess ofpermanganate.5. Interferences5.1 The possibility of interference from organic constitu-ents, which may react with perma
8、nganate, must be consideredwith each compound encountered.Asluggish reaction or vagueend point, will suggest interference. Inorganic builders ordetergents, such as silicates, phosphates, or carbonates, do notinterfere. Organic detergents or wetting agents may interfere.EDTA-type sequestrants do inte
9、rfere (see Terminology D 459).6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. 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 speci
10、fications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent
11、 water conformingto Specification D 1193.6.3 Potassium Permanganate, Standard Solution (0.1 N)Dissolve 3.2 g of potassium permanganate (KMnO4)in100mL of water and dilute the solution with water to 1 L. Allowthe solution to stand in the dark for two weeks and then filterthrough a fine-porosity sinter
12、ed-glass crucible. Do not wash thefilter. Store the solution in glass-stoppered, amber-colored glassbottles.NOTE 2Do not permit the filtered solution to come into contact withpaper, rubber, or other organic material.6.3.1 Weigh accurately to the nearest 0.1 mg about 0.3 gstandard sodium oxalate (Na2
13、C2O4, previously dried at 105C).Transfer to a 400-mL beaker. Add 250 mL of H2SO4(5+95),freshly boiled for at least 10 min and cooled to 27 6 3C. Stiruntil the oxalate has dissolved. Add 0.1 N KMnO4solutionrapidly from a buret (25 to 30 mL/min) while stirring slowlybut constantly until about 40 mL ha
14、ve been added. Let stand1This test method is under the jurisdiction of ASTM Committee D12 on Soapsand Other Detergents and is the direct responsibility of Subcommittee D12.12 onAnalysis and Specifications of Soaps, Synthetics, Detergents and their Components.Current edition approved July 1, 2008. Pu
15、blished July 2008. Originally approvedin 1963. Last previous edition approved in 2003 as D 2180 89 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standa
16、rds Document Summary page onthe ASTM website.3Reagent 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 Ltd., Poole,
17、Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.until the pink color disappears. Heat the solution from
18、55 to60C and complete the titration promptly, adding the last 0.5 to1 mL dropwise, with particular care to let the color disappearbefore adding the next drop. Continue until a faint pink colorpersists for 30 s. Determine the amount of KMnO4solutionrequired to produce the same color in a blank of an
19、equalamount of special dilute acid at the same temperature. Calcu-late the normality of the KMnO4solution, N as follows:N 5 W/V 2 B! 3 0.0670 (1)where:W = grams of Na2C2O4used,V = millilitres of KMnO4solution required for the titrationof the standard, andB = millilitres of KMnO4solution required for
20、 titration ofthe blank.6.4 Sodium Oxalate,4,5primary standard grade.6.5 Sulfuric Acid (1+9)To 900 mL of cool water, care-fully add 100 mL of concentrated sulfuric acid (H2SO4,spgr1.84). Mix well and cool.6.6 Sulfuric Acid (5+95)To 950 mL of cool water, care-fully add 50 mL of concentrated H2SO4. Mix
21、 well and cool.7. Sampling7.1 The material shall be well mixed just prior to samplingto ensure a representative sample for analysis, especially withcommercial products compounded of several ingredients. Ifsufficient product is available, a relatively large sample shouldbe weighed and put into soluti
22、on. An aliquot should then beused for the titration. See Section 8 for the recommendedamount.8. Procedure8.1 From a well mixed sample, weigh to the nearest 0.1 mg,a sample of sufficient size so that a120 aliquot will require atitration of at least 10 mL of 0.1 N KMnO4solution. Forexample, use 3.5 to
23、 4.0 g of a sample containing 5 % activeoxygen. Transfer this sample quantitatively to a 500-mLvolumetric flask, using 250 mL of water. Swirl the flask gentlyto dissolve the sample and avoid producing a foam should thesample contain foam-producing ingredients. Dilute to volumewith H2SO4(1+9) and mix
24、 thoroughly (Note 3). Immediatelypipet a 25-mL aliquot and titrate (Note 4) with standard 0.1 NKMnO4solution to a faint pink color. Prepare a blank anddetermine the amount of KMnO4solution necessary to producethe same pink color. Record the volume of titrant required forsample and blank. Replicate s
25、amples are advisable.NOTE 3Caution: When the dilute, H2SO4, is added, there is apossibility of vigorous CO2evolution from carbonates or bicarbonates inthe sample.NOTE 4Titrate slowly so as to avoid any considerable temporaryexcess of permanganate.9. Calculation9.1 Calculate the weight percentage of
26、active oxygen asfollows:Active oxygen as O, weight % 5 V 2 B!NA 3 0.008/W 3 100(2)where:V = millilitres of KMnO4solution required for titration ofthe sample,B = millilitres of KMnO4solution required for titration ofthe blank,N = normality of the KMnO4solution,A = aliquot factor (500/25 = 20), andW =
27、 grams of sample used.10. Keywords10.1 active oxygen; bleaches; perborate; percarborate;peroxideASTM 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 determin
28、ation 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 reviewed every five years andif not revised, either reapproved or wit
29、hdrawn. 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 theresponsible technical committee, which you may attend. If you feel that yo
30、ur 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 Conshohocken, PA 19428-2959,United States. Individual reprints (sin
31、gle 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).4This reagent is used for standardization purposes only.5National Institute of Standards and Technology Standard Sample 40C has beenfound satisfactory for this purpose.D 2180 89 (2008)2
