ASTM E1584-2011 Standard Test Method for Assay of Nitric Acid《硝酸化验的标准试验方法》.pdf

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1、Designation: E1584 11Standard Test Method forAssay of Nitric Acid1This standard is issued under the fixed designation E1584; 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 parentheses indicat

2、es the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers determination of the assay ofnitric acid by total acidity. This test method is suitable forconcentrations between approximately 50 and 70 %,

3、 calculatedas nitric acid.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 Review the current Material Safety Data Sheets (MSDS)for detailed information concerning toxicity, first aid proce-dures, and safety precautions.1

4、.4 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 limitations prior to use. Specific precau

5、-tionary statements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals3E200 Practice for Preparation, Standardization, and St

6、orageof Standard and Reagent Solutions for Chemical AnalysisE300 Practice for Sampling Industrial Chemicals3. Summary of Test Method3.1 Aweighed sample of acid is diluted in water and titratedwith 1.0 N sodium hydroxide solution, using phenolphthaleinas the end-point indicator.4. Significance and Us

7、e4.1 This test method provides a means for assaying nitricacid, based on total acidity. The concentration of nitric acid isimportant in many of the uses of nitric acid, includingspecification compliance and manufacturing control.5. Interferences5.1 Acids other than nitric, and compounds that consume

8、sodium hydroxide, will yield erroneously high results.6. Apparatus6.1 Erlenmeyer Flask, 250 mL, glass stoppered.6.2 Buret, 50 mL, Class A.NOTE 1A digital buret capable of measuring volumes to the nearest0.01 mL may be used in place of a conventional buret.7. Reagents7.1 Purity of ReagentsReagent gra

9、de chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.4Other grades may be used,provided it is first ascertained

10、that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type II or Type III of Specification D1193.7.3 Phenolphthalein

11、Indicator Solution (10 g/L)Dissolve1 g of phenolphthalein in 100 mL of ethanol (95 %), methanol,or isopropanol.51This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current e

12、dition approved Aug. 1, 2011. Published September 2011. Originallyapproved in 1993. Last previous edition approved in 2005 as E1584 00 (2005)1.DOI: 10.1520/E1584-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Bo

13、ok of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, D

14、C. For suggestions 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.5This reagent is a

15、lso described in Practice E200.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.4 Sodium Hydroxide, Standard Solution (1.0 N)Prepareand standardize in accordance with Practice E200, remember-ing to record the temperature of the NaOH

16、 solution during thestandardization to the nearest C.NOTE 2Because of atmospheric CO2absorption by NaOH, 1.0 NNaOH solutions will need frequent standardization.8. Safety Precautions8.1 Nitric acid is dangerous if handled improperly. It is astrong corrosive acid and a strong oxidizer. Contact with ot

17、hermaterial may cause fire. Avoid inhalation of fumes or mist andany contact with skin or eyes.8.2 Clean up all spills immediately by covering the spillwith vermiculite or some other inert absorbent material andsweeping it into a pan. Dispose of the vermiculite by floodingwith water and discarding i

18、n a suitable container. Flush the areawith water.9. Sampling9.1 Sampling of nitric acid is not within the scope of thistest method. General guidelines for sampling may be found inPractice E300.9.2 The sample to be analyzed shall be considered to be thatsample in a single bottle submitted to the anal

19、ytical laboratory.10. Procedure10.1 Tare to the nearest 0.1 mg a glass stoppered 250-mLErlenmeyer flask containing approximately 15 mL of water.10.2 Remove the stopper. Using a suitable pipet, quicklyadd an appropriate volume of sample (depending on the acidstrength as given in Table 1), while keepi

20、ng the tip of the pipetjust above the surface of the liquid. Immediately replace thestopper, and reweigh the flask to the nearest 0.1 mg to obtainthe weight of the sample.NOTE 3A disposable dropping pipet is convenient for the sampletransfer.10.3 Remove the stopper, add 50 mL of water and 4 dropsof

21、phenolphthalein indicator solution to the flask, and swirl tomix the contents. Record the temperature of the 1.0 N NaOHsolution, and then titrate the sample to a pale pink end point.Record the volume of the titrant to the nearest 0.01 mL.11. Calculation11.1 If necessary, correct the buret reading fo

22、r calibrationerrors, and record the volume of the titrant as V and itstemperature during the titration as t.11.2 Correct the normality of the sodium hydroxide stan-dard solution for any difference in temperature between time ofstandardization and time of use in accordance with the follow-ing equatio

23、n:N 5 Ns1 0.00035 s 2 t! (1)where:N = normality of NaOH solution at time of titration,Ns= normality of NaOH solution at time of standardiza-tion,s = temperature of NaOH during standardization, C, andt = temperature of NaOH during titration C.11.3 Calculate the assay as percent nitric acid as follows

24、:nitric acid, % by weight 5VN 3 6.301W(2)where:V = corrected NaOH solution required for titration of thesample, mL,N = normality of the NaOH solution corrected for tempera-ture at time of titration, andW = sample used, g.12. Report12.1 Report the percent of nitric acid to the nearest 0.01 %.13. Prec

25、ision and Bias13.1 PrecisionThe following criteria should be used forjudging the acceptability of results (Note 4):13.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be0.0914 % absolute at 54 df. The 95 % limit for the differencebetween two

26、such runs is 0.26 % absolute.13.1.2 Laboratory Precision (Within-Laboratory, Between-Days Variability), Formerly Called Repeatability)The stan-dard deviation of results (each the average of duplicates),obtained by the same analyst on different days, has beenestimated to be 0.0892 % absolute at 27 df

27、. The 95 % limit forthe difference between two such averages is 0.25 % absolute.13.1.3 Reproducibility (Multilaboratory)The standard de-viation of results (each the average of duplicates), obtained byanalysts in different laboratories, has been estimated to be0.1720 % absolute at 8 df. The 95 % limi

28、t for the differencebetween two such averages is 0.48 % absolute.NOTE 4The preceding precision estimates are based on an interlabo-ratory study of analyses performed in 1993 to 1994 on three samples ofnitric acid with average assays of 56.49 %, 65.54 %, and 69.65 %. Oneanalyst in each of nine labora

29、tories performed duplicate determinationsand repeated one day later, for a total of 108 determinations.6PracticeE180 was used in developing these precision estimates.13.2 BiasThe bias of this test method cannot be deter-mined unless a suitable reference material becomes available.14. Keywords14.1 as

30、say; nitric acid; titrimetric method6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:E15-1041.TABLE 1 Sample Size for Assay of Nitric AcidAHNO3, % Sample Size, mL Nominal Weight, g70 2.5 6 0.2 3.665 2.8 6 0.2 3.960 3.1 6 0.2 4.35

31、5 3.4 6 0.2 4.650 3.8 6 0.2 5.0AIn some cases, where the concentration range of the sample is unknown, apreliminary test may be required to determine the proper size test sample to use.E1584 112ASTM International takes no position respecting the validity of any patent rights asserted in connection w

32、ith any item mentionedin this standard. Users 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 tec

33、hnical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. 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 considera

34、tion at a meeting of theresponsible technical 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 H

35、arbor Drive, PO Box C700, West Conshohocken, 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 photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E1584 113