1、Designation: D2180 17Standard Test Method forActive Oxygen in Bleaching Compounds1This standard is issued under the fixed designation D2180; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in par
2、entheses 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, and peroxides but not
3、 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-bility of regulatory limi
4、tations prior to use. Safety Data Sheets(formerly known as Material Safety Data Sheets) are availablefor reagents and materials. Review them for hazards prior tousage.2. Referenced Documents2.1 ASTM Standards:2D459 Terminology Relating to Soaps and Other DetergentsD1193 Specification for Reagent Wat
5、er3. Terminology3.1 Definitions: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. Summa
6、ry of Test Method4.1 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
7、 organics present 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 organicconstituents, which may r
8、eact with permanganate, must beconsidered with each compound encountered. A sluggishreaction or vague end point, will suggest interference. Inor-ganic builders or detergents, such as silicates, phosphates, orcarbonates, do not interfere. Organic detergents or wettingagents may interfere. EDTA-type s
9、equestrants do interfere (seeTerminology D459).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
10、,where such specifications 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 understoo
11、d to mean reagent water conformingto Specification D1193.6.3 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
12、-porosity sintered-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 sod
13、ium oxalate (Na2C2O4, previously dried at 105C).1This test method is under the jurisdiction of ASTM Committee D12 on Soapsand Other Detergentsand is the direct responsibility of Subcommittee D12.12 onAnalysis and Specifications of Soaps, Synthetics, Detergents and their Components.Current edition ap
14、proved Jan. 1, 2017. Published February 2017. Originallyapproved in 1963. Last previous edition approved in 2008 as D2180 89 (2008).DOI: 10.1520/D2180-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMS
15、tandards volume information, refer to the standards 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 Stan
16、dards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis inter
17、national standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Com
18、mittee.1Transfer 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 have been added. Let stand
19、until the pink color disappears. Heat the solution from 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 KMnO4solu
20、tionrequired to produce the same color in a blank of an 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! 30.0670# (1)where:W = grams of Na2C2O4used,V = millilitres of KMnO4solution required for the titrationof the st
21、andard, andB = millilitres of KMnO4solution required for titration ofthe blank.6.4 Sodium Oxalate,4,5primary standard grade.6.5 Sulfuric Acid (1+9)To 900 mL of cool water, carefullyadd 100 mL of concentrated sulfuric acid (H2SO4, sp gr 1.84).Mix well and cool.6.6 Sulfuric Acid (5+95)To 950 mL of coo
22、l water, care-fully add 50 mL of concentrated H2SO4. Mix 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 rela
23、tively large sample shouldbe weighed and put into solution. 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 le
24、ast 10 mL of 0.1 N KMnO4solution. Forexample, use 3.5 to 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-produc
25、ing ingredients. Dilute to volumewith H2SO4(1+9) and mix 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 vol
26、ume of titrant required forsample and blank. Replicate samples 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 permangana
27、te.9. Calculation9.1 Calculate the weight percentage of active oxygen asfollows:Active oxygen as O, weight % 5 V 2 B!NA 30.008/W# 3100(2)where:V = millilitres of KMnO4solution required for titration ofthe sample,B = millilitres of KMnO4solution required for titration ofthe blank,N = normality of the
28、 KMnO4solution,A = aliquot factor (500/25 = 20), andW = grams of sample used.10. Keywords10.1 active oxygen; bleaches; perborate; percarborate; per-oxideASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. U
29、sers of this standard are expressly advised that determination 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 eve
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31、ical committee, which you may attend. If you feel that your 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 Conshohock
32、en, PA 19428-2959,United States. Individual reprints (single 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). Permission rights to photoc
33、opy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ reagent is used for standardization purposes only.5National Institute of Standards and Technology Standard Sample 40C has beenfound satisfactory for this purpose.D2180 172
