1、Designation: D 2192 06Standard Test Method forPurity of Aldehydes and Ketones1This standard is issued under the fixed designation D 2192; 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 parent
2、heses 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 the purityof certain commercially available aldehydes and ketones.1.2 In addition to all aldehydes and k
3、etones, all compoundssuch as vinyl alkyl ethers, acetals, and ketals, that hydrolyzeunder the conditions of the reaction to form free carbonylgroups, react with the reagent and consequently interfere.Water, alcohols, saturated esters, and hydrocarbons do not reactwith the reagent, but large amounts
4、of inert organic solvents areundesirable because of the effect on the indicator.1.3 For purposes of determining conformance of an ob-served or a calculated value using this test method to relevantspecifications, test result(s) shall be rounded off “to the nearestunit” in the last right-hand digit us
5、ed in expressing thespecification limit, in accordance with the rounding-off methodof Practice E 29.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if
6、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. For specific hazardstatements, see Section 7.1.6 For hazard information and guidance, see
7、the suppliersMaterial Safety Data Sheet.2. Referenced Documents2.1 ASTM Standards:2D 268 Guide for Sampling and Testing Volatile Solventsand Chemical Intermediates for Use in Paint and RelatedCoatings and MaterialD 1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test
8、 Data toDetermine Conformance with SpecificationsE 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysisE 222 Test Methods for Hydroxyl Groups Using AceticAnhydride Acetylation3. Summary of Test Method3.1 Hydroxylamine hydrochloride is con
9、verted in part tofree hydroxylamine by reaction with a known amount ofaqueous triethanolamine.NH2OHHCl 1 HOCH2CH2!3N (1)NH2OH 1 HOCH2CH2!3NHClThe free hydroxylamine reacts with the aldehyde or ketoneto form the corresponding oxime.RR1C50 1 NH2OHRR1C5H5NOH 1 H2O, (2)where:R = alkyl group andR1= alkyl
10、 group or hydrogen.The amount of hydroxylamine consumed, which is deter-mined by titration of the excess base with standard sulfuricacid, is a measure of the aldehyde or ketone originally present.3.2 Since the determination is based on an acidimetrictitration, a suitable correction must be applied i
11、f the sample isnot neutral to bromophenol blue indicator.4. Significance and Use4.1 This test method provides a measurement of purity(assay) of aldehydes and ketones. The results of these mea-surements can be used for specification acceptance.4.2 The precision of this test method is applicable only
12、tomaterial having a purity of 98 to 100 %.5. Apparatus5.1 Pressure Bottle, 200 to 350-mL capacity, with lever typeclosure and made of heat-resistant glass.5.2 Container for Pressure BottleA suitable safety deviceto contain the pressure bottle. A metal container with a hingedtop and perforated bottom
13、, a strong synthetic fabric or canvasbag, or a safety shield may be used.5.3 Ampoule, 1 or 2-mL capacity.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.35 on Solvents, Pla
14、sticizers, and Chemical Intermediates.Current edition approved June 1, 2006. Published June 2006. Originallyapproved in 1963. Last previous edition approved in 2000 as D 2192 96 (2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast
15、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.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 St
16、ates.5.4 Weighing Pipet, Lunge or similar type.5.5 Burets, 50-mL capacity.5.6 Transfer Pipet, 50-mL capacity.5.7 Glass Rod, 8-mm, several pieces approximately 1 in.long.5.8 Boiling Water Bath.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless oth
17、erwise indicated, 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 p
18、urity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type IV of Specification D 1193.6.3 Bromophenol Blue Indicator (0.04 % AlcoholicSolution)Dissolve 0.04 g
19、 of bromophenol blue (tetrabro-mophenolsulfonphthalein) in 100 mL of methyl alcohol. Titratethis solution with 0.1 N sodium hydroxide (NaOH) solution toa reddish-bronze color. If an off-color is obtained at this point,it is probably due to the age of the indicator and fresh indicatorshould be used t
20、o prepare a new solution.6.4 Cylinder Nitrogen.6.5 Hydroxylamine Hydrochloride, Standard (0.5 N Alco-holic Solution)Dissolve 35 g of hydroxylamine hydrochlo-ride (NH2OH HCl) in 150 mL of water and dilute to 1 L with99 % isopropanol.6.6 Isopropanol (99 %).6.7 Sulfuric Acid, Standard (0.5 N)Prepare an
21、d standard-ize 0.5 N sulfuric acid (H2SO4) in accordance with PracticeE 200, sections on Precision and Bias, Standardization withTris(hydroxymethyl)-Aminomethane, Calculation, and Stabil-ity.6.8 Triethanolamine, Standard (0.5 N Aqueous Solution)Dissolve 65 mL (74 g) of 98 % triethanolamine in water
22、anddilute to 1 L with water. Adjust the normality of this solutionso that it is slightly below the normality of the H2SO4beingused.7. Procedure7.1 Sample the material in accordance with Guide D 268.7.2 Add 15 mL of a 0.04 % alcoholic solution of bromophe-nol blue indicator to 500 mL of the hydroxyla
23、mine hydrochlo-ride solution. From a buret add 0.5 N triethanolamine until thesolution appears greenish-blue by transmitted light. Prepare thesolution fresh before each series of analyses.7.3 Prepare a sufficient number of heat-resistant pressurebottles to make all blank and sample determinations in
24、 dupli-cate. Replace the rubber gaskets if necessary and make sure thecaps can be fastened securely.7.4 Using a graduated cylinder, add 65 mL of the neutral-ized hydroxylamine hydrochloride to each bottle. Using atransfer pipet, add 50.0 mL of the 0.5 N triethanolaminesolution to each bottle.7.5 Bef
25、ore capping, purge the bottles for 2 min with a gentlestream of cylinder nitrogen. This is best accomplished bymeans of a glass tube inserted through the neck of the bottleand clamped so that the opening is just above the surface of theliquid.7.6 Reserve two of the bottles for the blank determinatio
26、n.Into each of the other bottles introduce an amount of samplecontaining not more than 0.015 mol of aldehyde or ketone. Forsubstantially pure material, weigh the specimen to the nearest0.1 mg, using the amount and procedure specified in Table 1.7.6.1 Warning: Acetaldehyde is a highly volatile, flam-
27、mable material; observe all necessary safety precautions.Handle samples only in a fume hood that is free from openflames, electric heaters, and other sources of ignition. Cool allsamples in an ice bath before the containers are opened. Weighthe acetaldehyde in a sealed glass ampoule. The actual proc
28、e-dure for filling and sealing the ampoule will vary somewhatwith the type of ampoule being used. One convenient methodis to pack commercially available ampoules in powdered, solidcarbon dioxide, introduce the specimen by means of a chilledhypodermic syringe, and seal the ampoule with a gas torch.7.
29、7 If a sealed glass ampoule is used to weigh the specimen,add several pieces of 8-mm glass rod and shake the bottlevigorously to break the ampoule.7.8 React the solutions at room temperature or at 98Caccording to the directions in Table 1.7.8.1 Reaction at 98C (WarningSee 7.8.1.1.)Placethe specimen
30、and blank bottles as close together as possible ina boiling water bath maintained at least at 98C for the timespecified in Table 1. Maintain sufficient water in the bath to justcover the liquid in the bottles. Remove the bottles from thebath after the specified time and allow them to cool in air tor
31、oom temperature. When the bottles have cooled, remove themfrom the safety device and continue as described in 7.9.7.8.1.1 Warning: Enclose each bottle securely in a suitablecontainer (metal or strong fabric) to restrain fragments of glassshould the pressure bottle rupture.7.8.2 Reaction at Room Temp
32、eratureAllow the specimensand the blanks to stand together at room temperature for thelength of time specified in Table 1. Swirl the bottles occasion-ally.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagent
33、s 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.TABLE 1 Specimen Size and Reaction ConditionsCompoundSpecimen,
34、gAMinimum ReactionConditionsTime,minTempera-ture, CAcetaldehyde ( 7.6.1) 0.5 to 0.7B30 25Methyl isobutyl ketone 1.1 to 1.4B60 25Methyl isoamyl ketone 1.1 to 1.7 30 25Isophorone 1.4 to 2.0 60 98AUse a suitable weighing pipet unless otherwise specified.BUse a sealed glass ampoule.D21920627.9 Cool each
35、 of the bottles slightly with tap water anduncap carefully to prevent loss of the contents. Allow thecontents to return to room temperature.NOTE 1Bromophenol blue indicator is temperature sensitive, and adifference of 10C at the end point causes a discrepancy of approximately0.3 mL of 0.5 N H2SO4. T
36、o achieve the best precision, it is imperative thatthe blank and the specimen be at the same temperature at the end point. Awater bath at room temperature is a convenient means of conditioning thespecimen and the blanks prior to the titration.7.10 Titrate each of the blanks with standard 0.5 N H2SO4
37、toa greenish-blue end point. Titrate each of the specimens withstandard 0.5 N H2SO4to the color of the blanks, approachingthe end point dropwise until the colors match by transmittedlight.NOTE 2If the solution becomes cloudy upon titration, add sufficientisopropanol to the specimen solution to effec
38、t homogeneity and add anequal amount of isopropanol also to the blank.7.11 Measure the temperature of the acid titrant. If thetemperature of the reagent at the time the analysis is made isnot the same as it was when the reagent was standardized,apply a correction to the normality. Use a DN/T of 0.00
39、014 perdegree Celsius in making the temperature correction.48. Calculation8.1 Calculate the weight percent of aldehyde or ketone, A,as follows (Note 3): Table 2A 5 B V!F 3 N!/S 3 100 (3)where:V =H2SO4required for titration of the specimen (see 7.10),mLB =H2SO4required for titration of the blanks (se
40、e 7.10),average, mLN = normality of the H2SO4,F = factor specified in Table 2 for the compound beingdetermined, andS = sample used (see 7.6), g.NOTE 3If the sample is acidic to bromophenol blue indicator, it isrecommended that a suitable correction be applied to the purity value.Refer to Test Method
41、 E 222.9. Report9.1 Report all results to the nearest 0.1 %.10. Precision and Bias10.1 PrecisionIn interlaboratory studies of this testmethod, the within-laboratory and between-laboratory standarddeviations were found to be as shown in Table 3 and Table 4.Based on these deviations, the following cri
42、teria should beused for judging the acceptability at the 95 % confidence levelof results obtained on materials having a purity of 98 to 100 %.10.2 RepeatabilityTwo results, each the mean of dupli-cates, obtained by the same operator on different days, shouldbe considered suspect if they differ by mo
43、re than the amountshown in Table 3.10.3 ReproducibilityTwo results, each the mean of dupli-cates, obtained by operators in different laboratories, should beconsidered suspect if they differ by more than the amountshown in Table 4.NOTE 4The preceding precision statements for acetaldehyde arebased upo
44、n two separate interlaboratory studies using two differentsamples having purities above 99 %. In the first study duplicate determi-nations were made on each sample by two analysts on two different daysin each of three laboratories. The second study included the same testprogram in each of four labor
45、atories.The precision statements for methyl isoamyl ketone and isophorone arebased upon two separate interlaboratory studies using two differentsamples of each chemical. In both studies, one analyst in each of elevendifferent laboratories made duplicate determinations on each sample ontwo different
46、days.10.4 BiasThe bias of this test method has not beendetermined because suitable standards are unavailable.11. Keywords11.1 aldehyde; ketones; purity4See table titled Temperature Correction Factors (F) of Practice E 200.TABLE 2 Aldehyde and Ketone FactorsCompound FactorAAcetaldehyde 0.04405Methyl
47、isobutyl ketone 0.1002Methyl isoamyl ketone 0.1142Isophorone 0.1382AFactor 5Molecular weight of compoundNumber of reacting groups 3 1000TABLE 3 Within-Laboratory DeviationsAcetalde-hydeMethylIsoamylKetoneIsophoroneStandard deviation 0.33 0.22 0.18Degrees of freedom 20 42 42Repeatability 1.0 2.6 0.6T
48、ABLE 4 Between-Laboratory DeviationsAcetalde-hydeMethylIsoamylKetoneIsophoroneStandard deviation 0.33 0.41 0.63Degrees of freedom 20 19 19Reproducibility 1.0 1.2 1.9D2192063SUMMARY OF CHANGESCommittee D01.35 has identified the location of selected changes to this standard since the last issue(D 2192
49、 - 96 (2000) that may impact the use of this standard. (Approved June 1, 2006.)(1) Added reference to Practice E29 in 1.3 of the Scopesection.(2) Added Practice E29to list of Referenced Documents.ASTM International takes no position respecting the validity of any patent rights asserted in connection with 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 sub
