1、Designation: D2989 01 (Reapproved 2011)Standard Test Method forAcidity-Alkalinity of Halogenated Organic Solvents andTheir Admixtures1This standard is issued under the fixed designation D2989; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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 Department of Defense.1. Scope1.1 This test metho
3、d covers the determination of acidity inhalogenated organic solvents and admixtures thereof. Thealkalinity may be determined utilizing Test Method D2106,bysubstituting the end point measured at pH 7 by bromothymolblue or pH meter.1.2 The values stated in SI units are to be regarded asstandard. No ot
4、her units of measurement are included in thisstandard.1.3 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
5、of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2D2106 Test Methods for Determination of Amine AcidAcceptance (Alkalinity) of Halogenated Organic SolventsD2110 Test Method for pH of Water Extractions of Halo-
6、genated Organic Solvents and Their Admixtures3. Summary of Test Method3.1 A sample of halogenated solvent or admixture is mea-sured for pH using Test Method D2110. If the pH of the sampleis above 7.0, the alkalinity is determined using Test MethodD2106 (to an end point of pH 7). If the pH is below 7
7、.0, thefree acid content of the halogenated organic solvent or admix-ture is determined after water extraction using Procedure A, orcan be determined directly using Procedure B.3.1.1 Procedure A, using glass electrode pH meter, or3.1.2 Procedure B, anhydrous methanolic sodium hydroxidetitration.4. S
8、ignificance and Use4.1 This test method can be used to establish manufacturingand purchasing specifications. It can also be used to determinethe condition of solvents in use.5. Apparatus5.1 Separatory Funnel, 250-mL.5.2 Graduated Cylinder, 100 mL.5.3 Volumetric Pipets, 1 mL, 10 mL, 25 mL, 50 mL.5.4
9、Beaker, 100 mL.5.5 Borosilicate or Stainless Steel Beaker,2L.5.6 Erlenmeyer Flask, 100 mL.5.7 pH Meter with pH Electrodes.5.8 Buret,10mL.5.9 Volumetric Flask, 100 mL, 1 L.5.10 Micro Buret, 5 mL, Class A or Syringe, 100 L.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all te
10、sts. 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.3Other grades may beused, provided it is first ascertained that the reagent is ofsuff
11、iciently high purity to permit its use without lessening theaccuracy of the determination.6.2 WaterPrepare neutral, distilled or deionized water asfollows: Boil 1 L of distilled or deionized water for 5 min in aborosilicate glass or stainless steel container, then cover andcool to room temperature.
12、Titrate to a pH of 7.0 to 7.3 witheither 0.01 N sodium hydroxide (NaOH) solution or 0.01 Nhydrochloric acid (HCl), depending upon whether the initialpH is above or below 7.1This test method is under the jurisdiction of ASTM Committee D26 onHalogenated Organic Solvents and Fire Extinguishing Agents a
13、nd is the directresponsibility of Subcommittee D26.04 on Test Methods.Current edition approved Aug. 1, 2011. Published November 2011. Originallyapproved in 1971. Last previous edition approved in 2006 as D2989 01 (2006)1.DOI: 10.1520/D2989-01R11.2For referenced ASTM standards, visit the ASTM website
14、, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggest
15、ions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 1
16、00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 Bromothymol Blue Indicator Solution (0.1 %)Indica-tor solution may be purchased from a laboratory supply houseor prepared as follows: Dissolve 0.1 g of dibromothymolsulfonephthalein in 1.6 mL of 0.1 N NaOH solutio
17、n and diluteto 100 mL with methanol.6.4 Sodium Hydroxide Solution (0.01 N), ProcedureADissolve4gofsodium hydroxide (NaOH) in boiled,neutral, distilled or deionized water and dilute to 1000 mL.Prepare 0.01 N NaOH solution by diluting 10.0 mL of the 0.1N NaOH to 100 mL with boiled, neutral, distilled
18、or deionizedwater in a calibrated volumetric flask. Standardize this 0.01 NNaOH by any accepted procedure to determine the exactnormality. This reagent is also available from most supplyhouses. Protect the reagent from absorption of atmosphericcarbon dioxide and standardize weekly.6.5 Sodium Hydroxi
19、de Methanolic Solution (0.01 N), Pro-cedure BDissolve4gofACSreagent grade sodium hydrox-ide (NaOH) in ACS reagent grade anhydrous methanol anddilute to 1000 mL with ACS reagent grade anhydrous metha-nol. Prepare 0.01 N methanolic NaOH solution by diluting 10.0mL of the 0.1 N NaOH to 100 mL with ACS
20、reagent gradeanhydrous methanol in a calibrated volumetric flask. Standard-ize this 0.01 N NaOH by any accepted procedure to determinethe exact normality. This reagent is also available from mostsupply houses. Protect the reagent from absorption of atmo-spheric carbon dioxide and standardize weekly.
21、7. Hazards7.1 Solvent HazardsContact with skin should be avoidedto prevent removal of natural oils. Solvents are not flammable,but each has a threshold limit value for contact with vapors.These threshold limits should be determined before a solvent islisted.7.2 NaOH as a solid or in solution can be
22、hazardous if thereis skin contact.8. Procedure8.1 Procedure APipet 50 mL of halogenated organicsolvent or admixture into a 250 mL separatory funnel contain-ing 50 mL of freshly boiled, neutral (pH 7.0 to 7.3), distilled ordeionized water. Shake the mixture for 2 min, then let standand allow the laye
23、rs to separate. Drain and discard the lower,organic layer from the separatory funnel and transfer the waterlayer to a 100mL beaker. Titrate the sample, with stirring,with 0.01 N NaOH using a 5 mL Class A buret until the pH isstable between 7.0 and 7.3 for 30 s. A100 L syringe can besubstituted for t
24、he micro buret. This technique is often used tomeasure very low levels of acidity, below 1 ppm. Technique isvery important. Titrate slowly, making sure the titrant fallscleanly into the water being titrated. Record the titer andcalculate the acidity in accordance with 9.1.8.2 Procedure BPipet 50 mL
25、of halogenated organicsolvent or admixture into a clean, dry, 100-mL Erlenmeyerflask. Add 1 mL of bromothymol blue indicator solution andtitrate, with stirring, with 0.01 N methanolic NaOH solution tothe bromothymol blue end point (see Note 1).NOTE 1The bromothymol blue end point may be interpreted
26、as anaqua (blue-green) to light blue color.9. Calculation9.1 ProcedureCalculate the acidity of halogenated or-ganic solvents or admixtures as equivalent hydrochloric acid inweight percent or weight ppm as follows:equivalent HCl, weight % 5 V3 N 3 0.0365!/W 3 100 (1)equivalent HCl, ppm 5 V 3 N 3 0.03
27、65!/W 3 1 000 000where:V = Volume in mL, NaOH solution required for titration ofthe sample,N = Normality of the NaOH solution, andW = Weight of the sample used, in g as weighed or g =sample volume in mL times its density in g per mL.10. Precision410.1 Using Method A, one standard deviation betweenre
28、sults of a sample run by different laboratories should be nomore than about 60.5 ppm. Within a laboratory, one standarddeviation between results should be no more than about 0.2ppm. Bias was not determined in this study.10.2 Using Method B, one standard deviation betweenresults of a sample run by di
29、fferent laboratories should be nomore than about 61.0 ppm. Within a laboratory, one standarddeviation between results should be no more than about 0.1ppm. Bias for this method is approximately +1 ppm.11. Keywords11.1 acidity; alkalinity; bromothymol blue; halogenated sol-vents; hydrochloric acid; pH
30、 meter; sodium hydroxide; titrationASTM 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 determination of the validity of any such patent rights, and the risk
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