1、Designation: D2106 07 (Reapproved 2017)Standard Test Methods forDetermination of Amine Acid Acceptance (Alkalinity) ofHalogenated Organic Solvents1This standard is issued under the fixed designation D2106; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of 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 U.S. Department of Defense.1. Scope1
3、.1 These test methods, where applicable, cover the deter-mination of the acid acceptance of halogenated organic sol-vents due to the presence therein of an organic amine titratableby standard acid. These test methods are suitable for samples of0.001 to 0.02 weight percent (10 200 ppm) alkalinity asN
4、aOH. Two test methods are covered as follows:1.1.1 Test Method ApH Method, and1.1.2 Test Method BIndicator Method.1.1.3 Test Method CGC Method.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 standar
5、d to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on P
6、rinciples for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D6806 Practice for Analysis of Halogenated Organic Sol-vents and Their Admixtures by Gas C
7、hromatographyE70 Test Method for pH of Aqueous Solutions With theGlass ElectrodeE200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical Analysis3. Terminology3.1 Definitions:3.1.1 amine acid acceptancethe degree to which an or-ganic amine present in
8、the halogenated organic solvent iscapable of absorbing or neutralizing acid generated by thesolvent or introduced into it from an external source.4. Significance and Use4.1 This test method is useful for the determination of theamount of acid acceptance contributed by amines or bases ascompared to o
9、ther acid-accepting compounds.5. Purity of Reagents5.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications
10、are available.3Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean distilled water
11、 or water ofequal purity. Additional requirements are specified in 8.1 and12.1.TEST METHOD ApH METHOD6. Summary of Test Method6.1 The amine acid acceptance of the halogenated organicsolvent is determined, after extraction into a volume of waterpreadjusted to a pH of 3.9, by titrating with standard a
12、cid to apH of 3.9. The extraction is performed either by stirring the1These test methods are under the jurisdiction of ASTM Committee D26 onHalogenated Organic Solvents and Fire Extinguishing Agents and are the directresponsibility of Subcommittee D26.04 on Test Methods.Current edition approved Nov.
13、 1, 2017. Published December 2017. Originallyapproved in 1962. Last previous edition approved in 2012 as D2106 07 (2012).DOI: 10.1520/D2106-07R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、 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 Standards for
15、 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 international
16、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) Committee.1i
17、mmiscible liquids mechanically or by shaking the immisciblelayers of liquids manually.7. Apparatus7.1 pH Meter, equipped with a pH indicating electrode andpH reference electrode or combination electrode.7.2 Stirrer, electric stirring bar, air-driven or magnetic.8. Reagents8.1 WaterAdjust the pH of 1
18、 L (or any convenientquantity) of water to 3.9. Boil 1 L of distilled water for 5 minin a borosilicate glass or stainless steel container, then coverand cool to room temperature. Titrate a 50-mL aliquot to a pHof 3.8 to 4.0 with 0.01 N hydrochloric acid (HCl) (or 0.01 NNaOH if the pH is below 3.8).
19、From this titer, calculate thevolume of 0.01 N HCl (or NaOH) required to adjust the pH ofthe remaining 950 mL of boiled distilled water to a pH of 3.8to 4.0. The calculation is as follows:950503titer (1)Add the calculated amount of 0.01 N HCl (or NaOH)together with the titrated 50 mL aliquot of wate
20、r to the 950 mLstock and mix thoroughly. Determine the pH of a secondaliquot. If further adjustment is necessary to obtain a pH of 3.8to 4.0, repeat the preceding procedure.8.2 Hydrochloric Acid, Standard (0.01 N)Dilute 1.8 mLof concentrated hydrochloric acid (HCl, sp gr 1.19) to 1 L withwater and s
21、tandardize in accordance with Practice E200,Sections 20 through 23. Certified reagent of 0.01 N HCl may bepurchased from supply houses.8.3 pH 4.0 Buffer Solution, available from most supplyhouses.8.4 pH 7.0 Buffer Solution, available from most supplyhouses.NOTE 1Hydrochloric acid of about 0.01 to ab
22、out 0.02 N can be used.It can be difficult to see the end point when using hydrochloric acid muchbelow about 0.01 N and concentrations much above 0.02 N increase thelikelihood of over-titrating the end point when titrating samples of lowalkalinity. For alkalinity below about 0.00075 % (75 ppm), 0.01
23、 N HCl isappropriate. For alkalinity above about 75 ppm, 0.02 N HCl is appropriate.9. Procedure9.1 Calibrate the pH meter in accordance with Test MethodE70.9.1.1 Prepare a blank using 100 mL of water previouslyadjusted to pH 3.9, and subject it to the same type and degreeof agitation as the test sam
24、ples. Titrate the blank to pH 3.9 andrecord the volume of titrant as B.9.2 Using Mechanical AgitationTransfer 50 mL of thehalogenated organic solvent to a 150-mL beaker and add50 mL of water previously adjusted to a pH of 3.9. Insert astirrer, and stir as vigorously as possible for 10 s. Stop thesti
25、rrer and lift it out of the beaker.Allow the liquids to separate.Insert the pH meter electrodes into the separated aqueous upperlayer, avoiding contact of the electrodes with the solvent layer,and titrate the water layer with 0.01 N HCl to a pH of 3.9.When the end point has been reached, remove the
26、electrodesand reinsert the stirrer. Stir vigorously for 10 s again. Removethe stirrer, insert the electrodes, and again titrate to a pH of 3.9.Repeat the steps until additional stirring does not result in achange of pH (Note 2). Record the final titration and calculatethe amine acid acceptance. When
27、 a magnetic stirring bar isused, it is not necessary to remove it between agitation periods.NOTE 2If the readings of the pH meter are erratic because theelectrodes have been wet with halogenated solvent, it may be treated byrinsing the electrode with acetone or alcohol, followed by thoroughrinsing w
28、ith water and soaking in water for a short time.9.3 Using Hand AgitationIf no stirrer is available, theextraction and titration may be carried out as follows: Transfer50 mL of the halogenated organic solvent to a 250-mLglass-stoppered Erlenmeyer flask, add 50 mL of water pread-justed to a pH of 3.9,
29、 and stopper the flask. Shake vigorouslyfor 5 s. Pour the contents into a 150-mL beaker and allow theimmiscible liquids to separate into layers. Insert the pH meterelectrodes and titrate the water layer with 0.01 N HCl to a pHof 3.9. When the end point has been reached, remove theelectrodes, return
30、the liquids to the flask, and extract again for5 s. Repeat the titration. Repeat the extraction and titration untilno change in pH results from additional shaking (Note 2).Record the final titration and calculate the amine acid accep-tance.10. Calculation10.1 Calculate the Amine Acid Acceptance (alk
31、alinity) asNaOH, in weight percent as follows:Amine Acid Acceptance alkalinity!, as NaOH, Weight Percent5 (2)$V 2 B/2! 3 NX0.040#/W% 3100or as parts per million as follows:Amine Acid Acceptance alkalinity!, as NaOH, ppm5 (3)$V 2 B/2! 3 NX0.040#/W% 31000000where:V = millilitres HCl required for titra
32、tion of the sample, mL,N = normality of the HCl,B = millilitres HCl required for titration of the blank, mL,andW = weight sample used (or volume in millilitres times itsspecific gravity), g.11. Precision and Bias11.1 The precision limits of this test have been determinedas 0.0005 % (equivalent NaOH,
33、 weight percent).TEST METHOD BINDICATOR METHOD12. Summary of Test Method12.1 The amine acid acceptance of the halogenated organicsolvent is determined, after extraction into a volume of waterpreadjusted to the bromphenol blue end point yellow, bytitrating with standard acid to the bromphenol blue en
34、d point,blue to yellow.D2106 07 (2017)213. Reagents13.1 WaterAdd bromphenol blue indicator solution (1drop for each 10 mL of water) to 1 L (or any convenientvolume) of water and adjust to the bromphenol blue colorchange end point.13.2 Bromphenol Blue Indicator Solution (10 g/L)Dissolve1gofbromphenol
35、 blue in 100 mL of water.13.3 Hydrochloric Acid, Standard (0.01 N)See 8.2.14. Procedure14.1 Prepare a blank using 100 mL of water previouslyadjusted to the color change point of the indicator being used,and subject it to the same type and degree of agitation as thetest samples. Titrate the blank to
36、the color change point of theindicator and record the volume of titrant as B.14.2 Transfer 50 mL of the halogenated organic solvent to aclean 250-mL glass-stoppered Erlenmeyer flask, and add50 mL of water adjusted to the bromphenol blue end point(Note 3). Stopper the flask and shake for 10 s. Allow
37、theimmiscible liquids to separate, and titrate the aqueous upperlayer with 0.01 N HCl to the bromphenol blue end point.Stopper the flask, and again shake for 5 s. If the end point haschanged, titrate to the bromphenol blue end point again. Repeatuntil no change in indicator results when additional s
38、haking isdone. Record the titration and calculate the amine acid accep-tance.NOTE 3Methyl orange indicator solution, modified methyl orangeindicator solution, or bromothymol blue indicator solution may besubstituted for bromphenol blue indicator solution where an operator hasdifficulty observing cer
39、tain color changes.14.3 Mechanical agitation may be used as described in 9.2.15. Calculation15.1 See Section 10.16. Precision and Bias416.1 Precision determinations were performed at concentra-tions of 0.0009, 0.0018, and 0.0194 weight percent as NaOH.16.2 The standard deviation of results (each the
40、 average of5 replicates) obtained by different analysts on different dayswithin the same laboratory has been estimated to be 0.0002weight percent absolute at 12 degrees of freedom. The 95 %limit for the difference between two such averages is 0.0005weight percent absolute.16.3 The standard deviation
41、 of results (each the average of5 replicates) obtained by analysts in different laboratories hasbeen estimated to be 0.0003 weight percent absolute at 4degrees of freedom. The 95 % limit for the difference betweentwo such averages has been estimated to be 0.0008 weightpercent absolute.16.4 The bias
42、of this test method was not determined.TEST METHOD CGAS CHROMATOGRAPHYMETHOD17. Procedure17.1 Determine the weight ppm or weight percent of theamine or amines present using gas chromatography with a gaschromatographic method that is in compliance with PracticeD6806.17.2 It will be necessary to calib
43、rate the gas chromatographwith a known standard of the amine or amines present. Theknown standard should be of approximately the same concen-tration as the amine to be measured.17.3 If the amine is unknown it can be identified by GCmass spectroscopy.17.4 Calculate the Amine Acid Acceptance (alkalini
44、ty) bythe following formula:Amine Acid Acceptance alkalinity!, as NaOH5 (4)40 3ppmMWor40 3wt %MWwhere:40 = the molecular weight of NaOH,ppm = ppm of the amine as determined in 17.1,wt % = weight percent of the amine as determined in 17.1,andMW = the molecular weight of the amine.17.5 If more than on
45、e amine is present the amine acidacceptance (alkalinity) will be the sum of the acid acceptance(alkalinity) of the individual amines.18. Precision and Bias518.1 Precision and bias data was obtained with two differentamines, n-methyl morpholine at about 20 ppm as NaOH inperchloroethylene, and diisopr
46、opyl amine, at about 3 ppm intrichloroethylene.18.2 There was no statistically significant difference be-tween alkalinity as determined between Methods B (titrationwith indicator) and Method C (determination of amine by GC).No bias is present.18.3 The reproducibility of the method was found to aver-
47、age 2.1 % Relative Standard Deviation at 3 and 20 ppm.18.4 Repeatability was calculated at 6.39 % RDS, that istwo determinations should differ less than 6.39 % RSD(1.3 ppm at 20 ppm alkalinity).19. Keywords19.1 acid acceptance; alkalinity; amine acid acceptance;halogenated organic solvents4A Researc
48、h Report is available from ASTM International Headquarters.Request RR:D26-1012.5A Research Report is available from ASTM International Headquarters.Request RR:D26-1019.D2106 07 (2017)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any it
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