ASTM E411-17a Standard Test Method for Trace Quantities of Carbonyl Compounds with 2,4-Dinitrophenylhydrazine.pdf

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1、Designation: E411 17aStandard Test Method forTrace Quantities of Carbonyl Compounds with 2,4-Dinitrophenylhydrazine1This standard is issued under the fixed designation E411; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、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.1. Scope*1.1 This test method covers the determination of totalcarbonyl in the range from 0.5 to 50 g calculated as CO.1.2 This

3、 test method is intended to be general and does notinclude steps for sample preparation.1.3 Acetals that hydrolyze under the conditions of the testare also determined.1.4 Carbonyl derivatives such as acetals and imines that areeasily hydrolyzed may be determined by an alternative proce-dure.1.5 The

4、developed color is not stable and must be measuredwithin a specified period.NOTE 1Other test methods for the determination of traces of carbonylcompounds are given in Test Methods D1089, D1612, D2119, and D2191.1.6 Review the current appropriate Safety Data Sheets(SDS) for detailed information conce

5、rning toxicity, first aidprocedures, and safety precautions.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is ther

6、esponsibility 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 are given in Section 7 and Section 8.1.9 This international standard was developed in accor-dance with

7、internationally recognized principles on standard-ization established in the Decision on Principles 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:2

8、D1089 Method of Test for Carbonyl Content of Butadiene(Withdrawn 1984)3D1193 Specification for Reagent WaterD1612 Test Method for Acetone in Methanol (Withdrawn2011)3D2119 Test Method for Aldehydes in Styrene MonomerD2191 Test Method for Acetaldehyde Content of VinylAcetateD6809 Guide for Quality Co

9、ntrol and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by SpectrophotometryE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdr

10、awn 2009)3E300 Practice for Sampling Industrial Chemicals3. Summary of Test Method3.1 The sample containing traces of carbonyl compounds isreacted with an acidic solution of 2,4-dinitrophenylhydrazineto form the hydrazone which, upon reaction with potassiumhydroxide, forms a wine-red color, presumab

11、ly due to aresonating quinoidal ion. The intensity of the red color, whichis a function of the carbonyl concentration, is determinedphotometrically and the amount of carbonyl is read directlyfrom a previously prepared calibration curve. This test methodis based upon the work of Lappin and Clark.44.

12、Significance and Use4.1 This test method is applicable to the determination oftrace amounts of aldehydes and ketones in aqueous solutionsand a wide variety of organic solvents.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic, Industrial, Specialty and Related Chemicals an

13、d is the direct responsi-bility of Subcommittee D16.15 on Industrial and Specialty General Standards.Current edition approved July 1, 2017. Published July 2017. Originally approvedin 1970. Last previous edition approved in 2017 as E411 17. DOI: 10.1520/E0411-17a.2For referenced ASTM standards, visit

14、 the ASTM 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Lappin, G. R.

15、, and Clark, L. C., Analytical Chemistry, Vol 23, 1951, p. 541.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance wit

16、h 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.15. Interferences5.1 This test method has

17、been found to be relatively freefrom interferences. It is necessary, however, to test a sample toensure that it does not interfere.5.2 Carbonyl compounds containing conjugated unsatura-tion interfere by absorbing at a different wavelength than othercarbonyl compounds.5.3 Acetals that are only partia

18、lly hydrolyzed under theconditions of the test will interfere. A higher reaction tempera-ture is required to effect complete hydrolysis.5.4 Certain carbonyl compounds such as diisobutyl ketonehave been found to undergo incomplete reactions and thus givelow results. These compounds may be determined

19、if a suitablecalibration is made using the compound in question.5.5 Because of the extreme sensitivity of this test method, itis necessary to perform the test in a room from which acetoneor other carbonyl compound vapors are excluded.6. Apparatus6.1 Spectrophotometer or Photometer, capable of measur

20、inglight absorption at 480 nm and holding a 1-cm cell.NOTE 2If a filter photometer is used, a narrow band filter having itsmaximum transmission at approximately 480 nm should be used. Adiscussion of photometers and photometric practice is given in PracticeE60.6.2 Absorption Cells, 1-cm.6.3 All glass

21、ware must be cleaned before use. Rinsethoroughly with water and finally with methanol. Do not useacetone to dry the glassware.NOTE 3The precision and bias reported in this test method weredetermined using chromic acid cleaning solution to clean the glassware.The effect on precision and bias of using

22、 other cleaning materials has notbeen determined.7. Reagents7.1 Purity of ReagentsUnless otherwise indicated, it isintended that all reagents shall conform to the specifications ofthe Committee onAnalytical Reagents of theAmerican Chemi-cal Society, where such specifications are available.5Othergrad

23、es may be used, provided it is first ascertained that thereagent is of sufficiently high purity to permit its use withoutlessening the accuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Types II or III reagentwater as defined i

24、n Specification D1193.7.3 Methanol, Carbonyl-freeTo 4 L of methanol add 20 gof 2,4-dinitrophenylhydrazine and 2 mL of hydrochloric acid(HCl, sp gr 1.19). Reflux for 2 h and then distill usinga2to3-ft fractionating column. Discard the first 200 mLof distillate.Continue the distillation until approxim

25、ately 75 % of themethanol has distilled over.7.3.1 WarningDo not allow the pot to begin to go drybecause there is danger of a violent decomposition of theresidue. (See 8.2.) If stored in a tightly capped bottle, themethanol will remain carbonyl-free indefinitely. Properly pre-pared methanol will hav

26、e an absorbance of 0.08 or less whenused as a blank (11.2 11.4).7.4 Potassium Hydroxide Solution (100 g/L)Dissolve 100g of potassium hydroxide (KOH) in 200 mLof water. Cool anddilute to 1 L with methanol.7.5 2,4-Dinitrophenylhydrazine (1 g/L)Dissolve 0.10 g of2,4-dinitrophenylhydrazine (WarningSee 8

27、.2)in50mLofcarbonyl-free methanol containing 4 mL of hydrochloric acid(HCl, sp gr 1.19) and dilute to 100 mL with water. Thissolution is unstable and must be discarded after two weeks.8. Safety Hazards8.1 WarningThe toxicity of 2,4-dinitrophenylhydrazinehas not been established. For this reason, han

28、dle with custom-ary care.Avoid ingestion and contact of the compound with theskin and eyes.8.2 Warning2,4-Dinitrophenylhydrazine is an explosiveand may ignite violently in contact with an open flame orelectrical spark. Handle with caution.Avoid all sources of heat.9. Sampling9.1 Special precautions

29、may be necessary to ensure that thesample taken for analysis is representative of the whole. Referto Practice E300 for a detailed discussion of sampling proce-dures.10. Calibration10.1 Add 50 mL of carbonyl-free methanol to a 100-mLglass stoppered volumetric flask. To the flask transfer anamount of

30、the carbonyl compound being determined that willcontain 25 mg of CO, weighing to the nearest 0.1 mg (see Note4). Dilute the contents of the flask to the mark with carbonyl-free methanol and mix well (see Note 5). (See 5.5 and 6.3.)NOTE 4The correct weight may be calculated as follows:W 5 0.893 3 E (

31、1)where:W = weight, mg,E = equivalent weight of compound, and0.893 = derived as a solution to the equation: W 28/E = 25,where 28 is the molecular weight of CO, and 25 ismilligrams of CO to be determined. Solve thisequation for W. Thus: W =25E/28, whichsimplifies to W = (25/28) E. 25/28 = 0.893.NOTE

32、5For most routine work a calibration based on 2-butanone issatisfactory. (See 5.4.)10.2 Prepare a series of standards by transferring 2, 4, 6, 8,and 10-mL aliquots of this stock solution to respective 100-mLglass-stoppered volumetric flasks. Dilute the contents of eachflask to the mark with carbonyl

33、-free methanol and mix well.5Reagent 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 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and

34、the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E411 17a2Two millilitres of each of these standards contain approxi-mately 10, 20, 30, 40, and 50 g of carbonyl, respectively.Calculate the exact weight as follows:S 5 5.60 3 W 3 V!/E# (2)w

35、here:S = weight of carbonyl in 2 mL of solution, g,W = weight of sample added to stock solution, mg,E = equivalent weight of compound,V = volume of aliquot, mL, and5.60 = collection of constants: S =(W mg 1 g/1000 mg)/100mL (V mL/100 mL) (1 eq 2-butanone/E) (1 eq C= O/1 eq 2-butanone) (28 g/eqC=O)(1

36、000000ug/g)2=5.6(W V)/E.10.3 Using suitable pipets, transfer 2 mLof each standard torespective 25-mL glass-stoppered volumetric flasks. Developthe color and measure the absorbance of each standard asdescribed in 11.2 11.4.10.4 Plot, on linear graph paper, micrograms of carbonyl asa function of the n

37、et absorbance.NOTE 6If the photometer reading is transmittance, convert to absor-bance as follows:A 5 log10100/T (3)where:A = absorbance, andT = transmittance.11. Procedure11.1 Using a suitable pipet, transfer 2 mL of a samplecontaining 0.5 to 50 g of carbonyl to a 25-mL dry glass-stoppered volumetr

38、ic flask that has previously been tared to thenearest 0.1 mg. Restopper and again weigh to the nearest 0.1mg to obtain the exact sample weight. (See 5.5 and 6.3.)NOTE 7If 2 mL of the sample contains more than 50 g of carbonyl,a suitable dilution in water or carbonyl-free methanol should be made.11.2

39、 Transfer 2 mL of carbonyl-free methanol to a second25-mL glass-stoppered volumetric flask for use as a reagentblank.11.3 To each flask, transfer, by means of a pipet, 2 mLof the2,4-dinitrophenylhydrazine solution. Stopper and allow to setat room temperature for 30 6 2 min (see Note 8). Dilute to th

40、emark with the potassium hydroxide solution. Stopper and mixwell.NOTE 8If a determination of easily hydrolyzed imines and acetals isrequired, use a reaction temperature of 60C. A hot-water bath is aconvenient source of heat. Cool before adding the potassium hydroxidesolution.11.4 At 12 6 1 min after

41、 adding the potassium hydroxidesolution, measure the absorbance of each solution at approxi-mately 480 nm (see Note 9) in a 1-cm cell using a suitablephotometer. Use a 1-cm cell filled with water to set theinstrument at zero absorbance or 100 % transmittances.NOTE 9The maximum absorbance of the quin

42、oidal ion occurs at about430 nm. The absorbance-concentration relationship is more linear,however, at 480 nm. For this reason the latter wavelength is used.11.5 Calculate the net absorbance due to carbonyl com-pounds in the sample by subtracting the absorbance of thereagent blank from that of the sa

43、mple determinations.11.6 Refer to a previously prepared calibration curve todetermine the micrograms of carbonyl found.12. Calculations12.1 Calculate the carbonyl content of the sample as fol-lows:CO, g/g 5AB(4)where:A = weight of carbonyl found, g, andB = sample weight, g, or sample volume, mL sp g

44、r.12.2 If it is desired to express the carbonyl content as aspecific compound, multiply the content calculated above bythe factor E/28.01, where E is the equivalent weight of thecompound.13. Report13.1 Report the carbonyl content to the nearest 0.1 g/g.Duplicate runs that agree within 0.5 g/g absolu

45、te are accept-able for averaging (95 % probability).14. Precision and Bias14.1 PrecisionThe following criteria should be used forjudging the acceptability of results (see Note 10).14.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be 0.16g/g

46、 at 26 df. The 95 % limit for the difference between twosuch determinations is 0.4 g/g absolute.14.1.2 Laboratory Precision (Within-Laboratory, Between-Days Variability)The standard deviation of results (each theaverage of duplicates) obtained by the same analyst in differentdays, has been estimated

47、 to be 0.16 g/g absolute at 13 df. The95 % limit for the difference between two such averages is 0.4g/g absolute.14.1.3 Reproducibility (Multilaboratory)The coefficientof variation of results (each the average of duplicates), ob-tained by analysts in different laboratories has been estimatedto be 6.

48、04 % relative at 5 df. The 95 % limit for the differencebetween two such averages is 17 % relative.NOTE 10The precision estimates are based on an interlaboratory studyperformed in 1969 on two samples of methanol containing 4 and 24 g/gtotal carbonyl added as acetone. Seven laboratories analyzed the

49、samplesin duplicate on each of two days.6Practice E180 90 was used indeveloping these precision statements.14.2 BiasThe bias of this test method has not beendetermined due to the unavailability of suitable referencematerials.15. Quality Guidelines15.1 Laboratories shall have a quality control system inplace.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:E15-1006. ContactASTM CustomerService at serviceastm.org.E411 17a315.1.