ASTM E223-2008 781 Standard Test Methods for Analysis of Sulfuric Acid《硫酸分析的标准试验方法》.pdf

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1、Designation: E 223 08Standard Test Methods forAnalysis of Sulfuric Acid1This standard is issued under the fixed designation E 223; 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 i

2、ndicates the year of last reapproval. Asuperscript epsilon (e) 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. Scope*1.1 These test methods cover the analysis of sulfuric acid.1.2 The values state

3、d in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 The analytical procedures appear in the following order:SectionsTotal Acidity 8 to 16Baum Gravity 17 to 26Nonvolatile Matter 27 to 33Iron 34to43Sulfur Dioxide 44 to 51Arsenic 52 to 611.4 This sta

4、ndard 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 hazardsstatements

5、 are given in Section 5.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE1 Specification for ASTM Liquid-in-Glass ThermometersE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE 100 Specification for ASTM HydrometersE

6、 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysis3. Significance and Use3.1 These test methods provide for the

7、classification ofvarious grades of sulfuric acid and for the determination ofvarious impurities. Acid strength and impurity levels areimportant factors in many uses of sulfuric acid.4. Purity of Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicat

8、ed, 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 ofsufficiently high purity to permi

9、t its use without lessening theaccuracy of the determination.4.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II or Type IIIreagent water conforming to Specification D 1193.5. Hazards5.1 Sulfuric acid is a strong corrosive acid and is dangerousif imp

10、roperly handled. Avoid any skin or eye contact.5.2 Clean up all spills immediately by covering the spillwith vermiculite or some other inert absorbent material andsweeping into a pan. Dispose of the absorbent by flooding withwater and discarding in a suitable container. Flush the area withwater.6. P

11、hotometers and Photometric Practice6.1 Photometers and the photometric practice used in thesetest methods shall conform to Practice E60.7. Sampling7.1 Sampling of sulfuric acid is not within the scope of thesetest methods.1These test methods are under the jurisdiction of ASTM Committee E15 onIndustr

12、ial and Specialty Chemicals and are the direct responsibility of Subcommit-tee E15.02 on Product Standards.Current edition approved April 1, 2008. Published May 2008. Originallyapproved in 1965. Last previous edition approved in 2002 as E 223 96(2002)e1.2For referenced ASTM standards, visit the ASTM

13、 website, 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. Fo

14、r 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.1*A Summary of Changes

15、section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 The sample to be analyzed shall be considered to be thatsample in a single bottle submitted to the analytical laboratory.7.3 The size of t

16、he sample shall be sufficient to perform allanalyses without the reuse of any portion of the sample.TOTAL ACIDITY8. Scope8.1 This test method covers the determination of the totalacidity of 75 to 99 % mass (m/m) sulfuric acid. Two testmethods are given for weighing the sample, namely, the Delytube a

17、nd the snake tube test methods.9. Summary of Test Method9.1 Aweighed sample of acid is diluted in water and titratedwith standardized 0.5 meq/mL(N) sodium hydroxide solution,using phenolphthalein as the indicator.10. Interferences10.1 Acids other than sulfuric and compounds that consumesodium hydrox

18、ide will affect the accuracy of this test method.11. Apparatus11.1 Dely Tube (Fig. 1) or Snake Tube (Fig. 2).411.2 Buret, 100-mL, Class A, bulb-type.12. Reagents12.1 Phenolphthalein Indicator Solution (10 g/L)Dissolve1gofphenolphthalein in 100 mL of ethanol (95 %),methanol, or isopropanol.512.2 Sodi

19、um Hydroxide, Standard Solution (0.5 meq/mL(N)See Practice E 200.13. Procedure13.1 Dely Tube Test MethodInvert the sample bottleseveral times. (Hold the stopper in tight.) Insert the long arm ofa dry, weighed Dely tube and withdraw by suction a convenientsize sample depending upon the acid strength

20、as given in Table1 (Note 1). Invert the Dely tube and wipe the acid from thelong arm with disposable tissue several layers thick. Discardthe tissue immediately to avoid burning the fingers. Reweigh tothe nearest 0.0001 g and record the weight of the sample.Incline the tube so that the acid runs back

21、 nearly to the bend ofthe short arm. Attach the short arm to an elevated waterreservoir by means of a rubber tube closed near the lower endwith a pinch clamp. Insert the long arm of the Dely tube into400-mL glass beaker containing approximately 100 mL ofwater. Open the pinch clamp and flush the samp

22、le into thebeaker. Continue the flow of water until all acid is washed fromthe Dely Tube (Note 2 and Note 3). Wash the long end of theDely tube, collecting the washings in the beaker. Add 3 to 5drops of phenolphthalein indicator solution. Record the tem-perature of the 0.5 meq/mL(N) NaOH solution, a

23、nd then titratethe sample to a pink end point. Record the titration to thenearest 0.02 mL.NOTE 1The Dely tube can be marked at points equivalent to weightsgiven in Table 1.4The sole source of supply of the Suitable Dely and snake tubes known to thecommittee at this time is Corning Glass Works, Corni

24、ng, NY. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.5This reagent is also described in Practice E 200.FIG. 1 Dely

25、 TubeFIG. 2 Snake TubeTABLE 1 Sample Size for Total AcidityH2SO4, % mass (m/m) Sample Size, g98 1.9 to 2.294 2.0 to 2.390 2.1 to 2.485 2.2 to 2.680 2.3 to 2.777 2.4 to 2.875 2.5 to 2.9E223082NOTE 2The presence of acid in the Dely tube may be detected bycoloring the water in the reservoir with phenol

26、phthalein indicator and theminimum amount of dilute NaOH solution that will produce a slight pink.The water flowing through the tube is dicolorized as long as acid ispresent, and the appearance of a pink color indicates the absence of acid.NOTE 3The acid and water are separated by a bubble of air.13

27、.2 Snake Tube Test MethodInvert the sample bottleseveral times. (Hold the stopper in tight). Insert the capillaryend of a dry, weighed snake tube and withdraw by suction aconvenient size sample depending upon the acid strength asgiven in Table 1. Invert the tube so that the double bend is ina horizo

28、ntal position. Wipe the acid from the capillary withdisposable tissue several layers thick. Discard the tissueimmediately to avoid burning the fingers. Reweigh to thenearest 0.0001 g and record the weight of the sample. Sub-merge the capillary of the tube in approximately 100 mL ofwater contained in

29、 the 400-mL beaker. Force the weighedsample from the tube by a stream of water from a wash bottleby placing the delivery tip in the exposed end of the snake tube(Note 4). Wash the tube with 50 to 70 mLof water. Remove thetube and wash the outside free of acid. Swirl the contents of thebeaker gently

30、while washing. Accumulate all washings in thebeaker and add 3 to 5 drops of phenolphthalein indicatorsolution. Record the temperature of the 0.5 meq/mL(N) NaOHsolution, and then titrate the sample to a pink end point. Recordthe titration to the nearest 0.02 mL.NOTE 4Do not introduce the water into t

31、he snake tube too rapidly, asthis will cause spattering.14. Calculation14.1 If necessary, correct the buret reading for calibrationerrors and record the volume of titrant as V and the temperatureas t.14.2 Correct the normality of the sodium hydroxide stan-dard solution for any difference in temperat

32、ure between time ofstandardization and time of use according to the followingequation:N 5 Ns1 0.00014 s 2 t! (1)where:N = normality meq/mL(N) of NaOH solution at tempera-ture t during use,Ns= normality meq/mL(N) of NaOH solution at tempera-ture s during standardization,s = temperature of NaOH soluti

33、on during standardization,andt = temperature of NaOH solution during analysis.14.3 Calculate the total acidity as % mass (m/m) of sulfuricacid as follows:Sulfuric acid, % mass m/m!5VN 3 0.04904!W3 100 (2)where:V = corrected millilitre of NaOH solution required fortitration of the sample,N = meq/mL(N

34、) normality of the NaOH solution, andW = grams of sample used.15. Report15.1 Report the % mass (m/m) of sulfuric acid to the nearest0.01 % mass(m/m).16. Precision and Bias16.1 The following criteria should be used for judging theacceptability of results (see Note 5):16.1.1 Repeatability (Single Anal

35、yst)The standard devia-tion for a single determination has been estimated to be0.069 % mass (m/m) absolute at 56 df. The 95 % limit for thedifference between two such runs is 0.19 % mass (m/m)absolute.16.1.2 Laboratory Precision (Within-Laboratory, Between-Days VariabilityThe standard deviation of r

36、esults (each theaverage of duplicates), obtained by the same analyst ondifferent days, has been estimated to be 0.104 % mass (m/m)absolute at 28 df. The 95 % limit for the difference betweentwo such averages is 0.29 % mass (m/m) absolute.16.1.3 Reproducibility (Multilaboratory)The standard de-viatio

37、n of results (each the average of duplicates), obtained byanalysts in different laboratories, has been estimated to be0.124 % mass (m/m) absolute at 7 df. The 95 % limit for thedifference between two such averages is 0.35 % mass (m/m)absolute.NOTE 5These precision estimates are based on an interlabo

38、ratorystudy of analyses performed in 1963 on three samples containingapproximately 80, 90, and 95 % mass (m/m) sulfuric acid. One analyst ineach of ten laboratories performed duplicate determinations and repeatedone day later, for a total of 120 determinations.6Practice E 180 was usedin developing t

39、hese precision estimates.16.2 Since there is no accepted reference material fordetermining the bias for measuring the total acidity of sulfuricacid, the bias of this test method has not been determined.BAUM GRAVITY17. Scope17.1 This test method covers the determination of theBaum gravity of concentr

40、ated sulfuric acid by means of aglass hydrometer in the range from 57 to 66.2 Baum. TheBaum gravity is determined at 15.5C (60F). This testmethod is not applicable to readings above 66.2 Baum gravityunits.18. Definition18.1 Baum Gravitya unit of density based on specificgravity and defined by the fo

41、llowing equation:Baum gravity 5 145 2 145/sp gr# at 15.5/15.5C 60/60F! (3)19. Summary of Test Method19.1 A sample of sulfuric acid is placed in a hydrometercylinder and when the temperature is constant, the Baumgravity is read from the glass hydrometer.6Details of the interlaboratory study are avail

42、able from ASTM InternationalHeadquarters. Request RR: E15-1047.E22308320. Significance and Use20.1 The Baum gravity is used to classify various grades ofsulfuric acid. This test method is not applicable for accuratedeterminations of the concentration of sulfuric acid.21. Apparatus21.1 Hydrometer,7st

43、reamline or torpedo design, precisiongrade for liquids heavier than water in ranges from 57 to 62B and 63 to 67 B. The total length shall be approximately305 mm (12 in.) divided to 0.05 B over a 152-mm (6-in.)(approximate) scale and standardized at 15.5/15.5C (60/60F)with a tolerance of 0.05 B throu

44、ghout. The modulus is asfollows:B 5 145 2 145/sp gr# at 15.5/15.5C 60/60F! (4)Each of the hydrometers shall show on the scale themodulus.21.2 Thermometer, having a range from 2 to + 80C (30to 180F) and conforming to the requirements for Thermom-eter 15C (15F) as prescribed in Specification E1.21.3 C

45、ylinder, Hydrometer, glass, with or without lip, diam-eter 38 to 40 mm, height 325 to 375 mm.22. Temperature of Test22.1 Baum gravity shall be determined at 15.5 6 0.3C (606 0.5F).23. Procedure23.1 Rinse a clean hydrometer cylinder with the sample tobe tested, add the sample, and adjust the temperat

46、ure to 15.5 60.3C (60 6 0.5F). Place the cylinder in a vertical position ina location free of air currents. Insert the hydrometer in thesample. Push it down about 3 mm below the level at which itwill float and release it. Read the hydrometer when it has cometo rest, floating freely, and the temperat

47、ure is 15.5C (60F).The correct reading is that point on the hydrometer scale atwhich the surface of the liquid cuts the scale. Determine thispoint by placing the eye slightly below the level of the liquidand slowly raising it until the surface, first seen as a distortedellipse, appears to become a s

48、traight line cutting the hydrom-eter scale. Record as Baum gravity.24. Calculation24.1 Calculate the specific gravity for later calculations inaccordance with the following equation:sp gr 5145145 2 Be(5)25. Report25.1 Report the Baum gravity to the nearest 0.01 unit.26. Precision and Bias26.1 The fo

49、llowing criteria should be used for judging theacceptability of results (see Note 6):26.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be 0.018unit absolute at 48 df. The 95 % limit for the differencebetween two such runs is 0.05 unit absolute.26.1.2 Laboratory Precision (Within-Laboratory, Between-Days Variability)The standard deviation of results (each theaverage of duplicates), obtained by the same analyst ondifferent days, has been estimated to be 0.016 un