ASTM E411-2012 red 0047 Standard Test Method for Trace Quantities of Carbonyl Compounds with 2 4-Dinitrophenylhydrazine 《使用2 4-二硝基苯肼对羰基化合物痕量测定的标准试验方法》.pdf

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1、Designation:E41105 Designation: E411 12Standard 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 r

2、evision, 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.1. Scope*1.1 This test method covers the determination of total carbonyl in the range from 0.5 to 50 g calcul

3、ated as CO.1.2 This test method is intended to be general and does not include steps for sample preparation.1.3 Acetals that hydrolyze under the conditions of the test are also determined.1.4 Carbonyl derivatives such as acetals and imines that are easily hydrolyzed may be determined by an alternati

4、ve procedure.1.5 The developed color is not stable and must be measured within a specified period.NOTE 1Other test methods for the determination of traces of carbonyl compounds are given in Test Methods D1089, D1612, D2119, and D2191.1.6 Review the current appropriate Material Safety Data Sheets (MS

5、DS) for detailed information concerning toxicity, first aidprocedures, and safety precautions.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 This standard does not purport to address all of the safety concerns, if any

6、, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. Specific hazards statements are given in Note 4 and Section 8.2. Referenced Documents2.1 ASTM St

7、andards:2D1089 Test Method of Test for Carbonyl Content of Butadiene3D1193 Specification for Reagent WaterD1612 Test Method for Acetone in MethanolD2119 Test Method for Aldehydes in Styrene MonomerD2191 Test Method for Acetaldehyde Content of Vinyl AcetateE60 Practice for Analysis of Metals, Ores, a

8、nd Related Materials by SpectrophotometryE180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty ChemicalsE300 Practice for Sampling Industrial Chemicals3. Summary of Test Method3.1 The sample containing traces of carbonyl compounds is reacted

9、 with an acidic solution of 2,4-dinitrophenylhydrazine toform the hydrazone which, upon reaction with potassium hydroxide, forms a wine-red color, presumably due to a resonatingquinoidal ion. The intensity of the red color, which is a function of the carbonyl concentration, is determined photometric

10、ally andthe amount of carbonyl is read directly from a previously prepared calibration curve. This test method is based upon the work ofLappin and Clark.34. Significance and Use4.1 This test method is applicable to the determination of trace amounts of aldehydes and ketones in aqueous solutions and

11、awide variety of organic solvents.1This test method is under the jurisdiction of ASTM Committee E15 on Industrial and Specialty Chemicals and is the direct responsibility of Subcommittee E15.01 onGeneral Standards.Current edition approved MarchApril 1, 2005.2012. Published April 2005.June 2012. Orig

12、inally approved in 1970. Last previous edition approved in 20042005 asE411 045. DOI: 10.1520/E0411-05.10.1520/E0411-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer

13、 to the standards Document Summary page on the ASTM website.3Lappin, G. R., and Clark, L. C., Analytical Chemistry, Vol 23, 1951, p. 541.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous ve

14、rsion. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes se

15、ction appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Interferences5.1 This test method has been found to be relatively free from interferences. It is necessary, however, to test a sample to ensu

16、rethat it does not interfere.5.2 Carbonyl compounds containing conjugated unsaturation interfere by absorbing at a different wavelength than othercarbonyl compounds.5.3 Acetals that are only partially hydrolyzed under the conditions of the test will interfere. A higher reaction temperature isrequire

17、d to effect complete hydrolysis.5.4 Certain carbonyl compounds such as diisobutyl ketone have been found to undergo incomplete reactions and thus give lowresults. These compounds may be determined if a suitable calibration is made using the compound in question.5.5 Because of the extreme sensitivity

18、 of this test method, it is necessary to perform the test in a room from which acetone orother carbonyl compound vapors are excluded.6. Apparatus6.1 Spectrophotometer or Photometer, capable of measuring light absorption at 480 nm and holding a 1-cm cell.NOTE 2If a filter photometer is used, a narrow

19、 band filter having its maximum transmission at approximately 480 nm should be used. A discussionof photometers and photometric practice is given in Practice E60.6.2 Absorption Cells, 1-cm.6.3 All glassware must be cleaned before use. Rinse thoroughly with water and finally with methanol. Do not use

20、 acetone todry the glassware.NOTE 3The precision and bias reported in this test method were determined using chromic acid cleaning solution to clean the glassware. The effecton precision and bias of using other cleaning materials has not been determined.7. Reagents7.1 Purity of ReagentsUnless otherw

21、ise indicated, it is intended that all reagents shall conform to the specifications of theCommittee on Analytical Reagents of the American Chemical Society, where such specifications are available.4Other grades maybe used, provided it is first ascertained that the reagent is of sufficiently high pur

22、ity to permit its use without lessening the accuracyof the determination.7.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean Types II or III reagent wateras defined in Specification D1193.7.3 Methanol, Carbonyl-freeTo 4 L of methanol add 20 g of 2,4-dinitro

23、phenylhydrazine 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. Continuethe distillation until approximately 75 % of the methanol has distilled over.7.3.1 WarningDo not allow the pot to begin

24、to go dry because there is danger of a violent decomposition of the residue. (See8.2.) If stored in a tightly capped bottle, the methanol will remain carbonyl-free indefinitely. Properly prepared methanol will havean absorbance of 0.08 or less when used as a blank (11.2-11.4).7.4 Potassium Hydroxide

25、 Solution (100 g/L)Dissolve 100 g 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 of 2,4-dinitrophenylhydrazine (WarningSee 8.2) in 50 mL ofcarbonyl-free methanol containing 4 mL of hydrochloric acid (HCl, sp

26、gr 1.19) and dilute to 100 mL with water. This solution isunstable and must be discarded after two weeks.8. Safety Hazards8.1 WarningThe toxicity of 2,4-dinitrophenylhydrazine has not been established. For this reason, handle with customarycare. Avoid ingestion and contact of the compound with the s

27、kin and eyes.8.2 Warning2,4-Dinitrophenylhydrazine is an explosive and may ignite violently in contact with an open flame or electricalspark. Handle with caution. Avoid all sources of heat.9. Sampling9.1 Special precautions may be necessary to ensure that the sample taken for analysis is representat

28、ive of the whole. Refer toPractice E300 for a detailed discussion of sampling procedures.10. Calibration10.1 Add 50 mL of carbonyl-free methanol to a 100-mL glass stoppered volumetric flask. To the flask transfer an amount ofthe carbonyl compound being determined that will contain 25 mg of CO, weigh

29、ing to the nearest 0.1 mg (see Note 4). Dilute the4Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., P

30、oole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.E411 122contents 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 fol

31、lows:W 5 0.893 3 E (1)E0411-12_1Ewhere:W = weight, mg, and weight, mg,E = equivalent weight of compound.equivalent weight of compound, and0.893 = derived as a solution to the equation: W 3 28/E = 25, where 28 is the molecular weight of CO, and 25 is milligramsof CO to be determined. Solve this equat

32、ion for W. Thus: W =253 E/28, which simplifies to W = (25/28) E. 25/28= 0.893.NOTE 5For most routine work a calibration based on 2-butanone is satisfactory. (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-st

33、oppered volumetric flasks. Dilute the contents of each flask to the mark with carbonyl-free methanol and mix well. Twomillilitres of each of these standards contain approximately 10, 20, 30, 40, and 50 g of carbonyl, respectively. Calculate the exactweight as follows:E0411-12_2Vwhere:S = weight of c

34、arbonyl in 2 mL of solution, g,W = weight of sample added to stock solution, mg,E = equivalent weight of compound, andV = volume of aliquot, mL.volume of aliquot, mL, and5.60 = collection of constants: S =(W mg 1 g/1000 mg)/100 mL (V mL/100 mL) (1 eq 2-butanone/E)(1eqC=O/1eq2-butanone) (28 g/eqC=O)(

35、1000000 ug/g)2=5.6(W V)/E.10.3 Using suitable pipets, transfer 2 mL of each standard to respective 25-mL glass-stoppered volumetric flasks. Develop thecolor and measure the absorbance of each standard as described in 11.2-11.4.10.4 Plot, on linear graph paper, micrograms of carbonyl as a function of

36、 the net absorbance.NOTE 6If the photometer reading is transmittance, convert to absorbance as follows:E0411-12_3where:A = absorbance, andT = transmittance.11. Procedure11.1 Using a suitable pipet, transfer 2 mL of a sample containing 0.5 to 50 g of carbonyl to a 25-mL dry glass-stopperedvolumetric

37、flask that has previously been tared to the nearest 0.1 mg. Restopper and again weigh to the nearest 0.1 mg to obtainthe 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

38、Transfer 2 mL of carbonyl-free methanol to a second 25-mL glass-stoppered volumetric flask for use as a reagent blank.11.3 To each flask, transfer, by means of a pipet, 2 mL of the 2,4-dinitrophenylhydrazine solution. Stopper and allow to set atroom temperature for 30 6 2 min (see Note 8). Dilute to

39、 the mark with the potassium hydroxide solution. Stopper and mix well.NOTE 8If a determination of easily hydrolyzed imines and acetals is required, use a reaction temperature of 60C. A hot-water bath is a convenientsource of heat. Cool before adding the potassium hydroxide solution.11.4 At 12 6 1 mi

40、n after adding the potassium hydroxide solution, measure the absorbance of each solution at approximately480 nm (see Note 9) in a 1-cm cell using a suitable photometer. Use a 1-cm cell filled with water to set the instrument at zeroabsorbance or 100 % transmittances.NOTE 9The maximum absorbance of t

41、he quinoidal ion occurs at about 430 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 compounds in the sample by subtracting the absorbance of the reagent blankfrom that of

42、 the sample determinations.11.6 Refer to a previously prepared calibration curve to determine the micrograms of carbonyl found.E411 12312. Calculations12.1 Calculate the carbonyl content of the sample as follows:E0411-12_4where:A = weight of carbonyl found, g, andB = sample weight, g, or sample volu

43、me, mL 3 sp gr.12.2 If it is desired to express the carbonyl content as a specific compound, multiply the content calculated above by the factorE/28.01, where E is the equivalent weight of the compound.13. Report13.1 Report the carbonyl content to the nearest 0.1 g/g. Duplicate runs that agree withi

44、n 0.5 g/g absolute are acceptable foraveraging (95 % probability).14. Precision and Bias14.1 PrecisionThe following criteria should be used for judging the acceptability of results (see Note 10).14.1.1 Repeatability (Single Analyst)The standard deviation for a single determination has been estimated

45、 to be 0.16 g/g at26 df. The 95 % limit for the difference between two such 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 different days, ha

46、s been estimated to be 0.16 g/g absolute at 13 df. The95 % limit for the difference between two such averages is 0.4 g/g absolute.14.1.3 Reproducibility (Multilaboratory) The coefficient of variation of results (each the average of duplicates), obtained byanalysts in different laboratories has been

47、estimated to be 6.04 % relative at 5 df. The 95 % limit for the difference between twosuch averages is 17 % relative.NOTE 10The precision estimates are based on an interlaboratory study performed in 1969 on two samples of methanol containing 4 and 24 g/g totalcarbonyl added as acetone. Seven laborat

48、ories analyzed the samples in duplicate on each of two days.5Practice E180 90 was used in developing theseprecision statements.14.2 BiasThe bias of this test method has not been determined due to the unavailability of suitable reference materials.15. Keywords15.1 aldehydes; carbonyl;2,4-dinitropheny

49、lhydrazine; ketonesSUMMARY OF CHANGESCommittee E15.01 has identified the location of selected changes to this standard since the last issue,E411-04,E411-05, that may impact the use of this standard. (Approved MarchApril 1, 2005.) 2012.)(1)Deleted (Formerly called Reapeatability) from the title of 14.1.2.(2)Changed the 95 % limit to 0.4 g/g absolute in 14.1.2.(3)Changed ppm to g/g throughout. ) Added explanations for variables 0.893 and 5.60 in Eq 1 and Eq 2, respectively.ASTM International takes no position respecting th