1、Designation: E 411 05Standard Test Method forTrace Quantities of Carbonyl Compounds with2,4-Dinitrophenylhydrazine1This standard is issued under the fixed designation E 411; 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 (e) 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 Thi
3、s 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 D 1089, D 1612, D 2119, andD 2191.1.6 Review the current appropriate Material Safety DataSheets (MSDS) for detailed inf
5、ormation concerning toxicity,first aid procedures, and safety precautions.1.7 The values stated in SI units are to be regarded as thestandard.1.8 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
6、 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardsstatements are given in Note 4 and Section 8.2. Referenced Documents2.1 ASTM Standards:2D 1089 Test Method for Carbonyl Content of ButadieneD 1193 Specifica
7、tion for Reagent WaterD 1612 Test Method for Acetone in Methanol (MethylAlcohol)D2119 Test Method for Aldehydes in Styrene MonomerD 2191 Test Method for Acetaldehyde Content of VinylAcetateE60 Practice for Molecular Absorption SpectrometricMethods for Chemical Analysis of Metals, Ores, andRelated Ma
8、terialsE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial ChemicalsE 300 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-dinitrophenylhyd
9、razineto form the hydrazone which, upon reaction with potassiumhydroxide, forms a wine-red color, presumably 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 directlyfro
10、m a previously prepared calibration curve. This test methodis based upon the work of Lappin and Clark.34. 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.5. Interferences5.
11、1 This test method has 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 Aceta
12、ls that are only partially 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 compo
13、unds may be determined if a suitablecalibration is made using the compound in question.1This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and is the direct responsibility of SubcommitteeE15.01 on General Standards.Current edition approved March 1,
14、2005. Published April 2005. Originallyapproved in 1970. Last previous edition approved in 2004 as E 411 04.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stand
15、ards Document Summary page onthe ASTM website.3Lappin, G. R., and Clark, L. C., Analytical Chemistry, Vol 23, 1951, p. 541.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Sta
16、tes.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-ing light absorption at 480 nm and holding a 1-cm cell.NOTE
17、 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 glassware must be cleaned before use. Rinsethoroughly with wate
18、r 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 other cleaning materials has notbeen determined.7. Reagen
19、ts7.1 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.4Othergrades may be used, provided it is first ascertained that ther
20、eagent 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 in Specification D 1193.7.3 Methanol, Carbonyl-freeTo 4 L o
21、f 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 mL of distillate.Continue the distillation until approximately 75 % of themethanol has distilled over.7.3.1 Warni
22、ngDo 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 have an absorbance of 0.08 or less whenused as a blank (11.
23、2-11.4).7.4 Potassium Hydroxide Solution (100 g/L)Dissolve 100g of potassium hydroxide (KOH) in 200 mL of water. Cool anddilute to 1 L with methanol.7.5 2,4-Dinitrophenylhydrazine (1 g/L)Dissolve 0.10 g of2,4-dinitrophenylhydrazine (WarningSee 8.2)in50mLofcarbonyl-free methanol containing 4 mL of hy
24、drochloric 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, handle with custom-ary care.Avoid ingestion and contact of
25、 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 may be necessary to ensure that thesample taken for ana
26、lysis is representative of the whole. Referto Practice E 300 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 the carbonyl compound being determined that willcontai
27、n 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 (1)where:W = weight, mg, andE = equivalent weight of co
28、mpound.NOTE 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 w
29、ith carbonyl-free methanol and mix well.Two 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)where:S = weight of carbonyl in 2 mL of solution, g,W = weight of sample added to
30、stock solution, mg,E = equivalent weight of compound, andV = volume of aliquot, mL.10.3 Using suitable pipets, transfer 2 mL of 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 line
31、ar graph paper, micrograms of carbonyl asa function of the net absorbance.NOTE 6If the photometer reading is transmittance, convert to absor-bance as follows:A 5 log10100/T (3)where:A = absorbance, andT = transmittance.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical So
32、ciety, 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 the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,M
33、D.E41105211. 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 volumetric 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
34、.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 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
35、means of a pipet, 2 mL of the2,4-dinitrophenylhydrazine solution. Stopper and allow to setat room temperature for 30 6 2 min (see Note 8). Dilute to themark with the potassium hydroxide solution. Stopper and mixwell.NOTE 8If a determination of easily hydrolyzed imines and acetals isrequired, use a r
36、eaction 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 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 suitabl
37、ephotometer. Use a 1-cm cell filled with water to set theinstrument at zero absorbance or 100 % transmittances.NOTE 9The maximum absorbance of the quinoidal ion occurs atabout 430 nm. The absorbance-concentration relationship is more linear,however, at 480 nm. For this reason the latter wavelength i
38、s 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 sample determinations.11.6 Refer to a previously prepared calibration curve todetermine the micrograms of carbonyl found.12. Calculations12.1 Calculate
39、 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 3 sp gr.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
40、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 absolute are accept-able for averaging (95 % probability).14. Precision and Bias14.1 PrecisionThe following criteria should be used forjudging the accept
41、ability 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 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, Bet
42、ween-Days Variability)The standard deviation of results (each theaverage of duplicates) obtained by the same analyst in differentdays, has been estimated 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 (Multilabor
43、atory)The coefficientof variation of results (each the average of duplicates), ob-tained by analysts in different laboratories has been estimatedto be 6.04 % relative at 5 df. The 95 % limit for the differencebetween two such averages is 17 % relative.NOTE 10The precision estimates are based on an i
44、nterlaboratorystudy performed in 1969 on two samples of methanol containing 4 and 24g/g total carbonyl added as acetone. Seven laboratories analyzed thesamples in duplicate on each of two days.5Practice E 180 90 was usedin developing these precision statements.14.2 BiasThe bias of this test method h
45、as not beendetermined due to the unavailability of suitable referencematerials.15. Keywords15.1 aldehydes; carbonyl;2,4-dinitrophenylhydrazine;ketones5Supporting data are available from ASTM Headquarters. Request RR: E15-1006.E411053SUMMARY OF CHANGESCommittee E15.01 has identified the location of s
46、elected changes to this standard since the last issue, (E411-04), that may impact the use of this standard. (Approved March 1, 2005.)(1) Deleted (Formerly called Reapeatability) from the title of14.1.2.(2) Changed the 95 % limit to 0.4 g/g absolute in 14.1.2.(3) Changed ppm to g/g throughout.ASTM In
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