1、Designation: D4423 10 (Reapproved 2015)Standard Test Method forDetermination of Carbonyls in C4Hydrocarbons1This standard is issued under the fixed designation D4423; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of carbonyls(ketones and aldehydes) in C4hydrocarbons. This test methodwas teste
3、d on polymerization-grade 1,3-butadiene.1.2 The applicable range for this test method is 0 mgkg to50 mgkg carbonyls calculated as acetaldehyde.1.3 Other C4hydrocarbons and their mixtures besidespolymerization-grade 1,3-butadiene could be tested using thissame test method. However, the precision sect
4、ion of this testmethod covers only carbonyls in applicable range as listed in1.2, as found in polymerization-grade 1,3-butadiene.1.4 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can causecentral nervous system, kidney and liver damage. Mercury, orits vap
5、or, may be hazardous to health and corrosive tomaterials. Caution should be taken when handling mercury andmercury containing products. See the applicable product Ma-terial Safety Data Sheet (MSDS) for details and EPAswebsitehttp:/www.epa.gov/mercury/faq.htmfor addi-tional information. Users should
6、be aware that selling mercuryand/or mercury containing products into your state or countrymay be prohibited by law.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafet
7、y 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.2. Referenced Documents2.1 ASTM Standards:2D484 Specification for Hydrocarbo
8、n Dry Cleaning Solvents(Withdrawn 1982)3D1193 Specification for Reagent WaterE1 Specification for ASTM Liquid-in-Glass Thermometers3. Summary of Test Method3.1 A measured amount of sample is added to an alcoholichydroxylamine hydrochloride solution that has been adjustedto a given coloration using e
9、ither alcoholic acid or base. Thecarbonyls will react with the hydroxylamine hydrochloridereleasing an equivalent amount of hydrochloric acid which isthen back-titrated to the original coloration.Ablank containingonly methanol and sample is titrated and the samples resultsare calculated using the bl
10、ank adjustment. Results are reportedas milligrams per kilogram carbonyls as acetaldehyde.4. Significance and Use4.1 The determination of the carbonyl content ofpolymerization-grade 1,3-butadiene is necessary, since in somepolymerization reactions, the presence of carbonyls in excessover some specifi
11、ed amount can have a deleterious effect uponthe polymer properties or the reaction itself, or both.5. Apparatus5.1 Bunsen ValvesAdevice constructed so that when usedwith an Erlenmeyer flask, the sample vapors can exit the flaskwhile protecting the flasks liquid contents. See Fig. 1 fordetails.5.2 Co
12、oling CoilPrepare a cooling coil by winding about10 cm to 15 cm of seamless copper tubing (about 6 mmdiameter) on a short length of pipe (about 1.5 cm to 2.0 cmdiameter), allowing sufficient length of tubing at the end of thecoil to connect it to the sample source.Attach a valve at a pointthat would
13、 not extend more than 8 cm above the surface of thecooling bath liquid. To the valve, attach a 6 cm to 8 cm length1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.D0.04 on C4 Hydro
14、carbons.Current edition approved April 1, 2015. Published May 2015. Originallyapproved in 1984. Last previous edition approved in 2010 as D4423 10. DOI:10.1520/D4423-10R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For An
15、nual 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Unite
16、d States1piece of tubing bent downward so that the hydrocarbon liquidcan be directed into the receiving container.5.3 Dewar FlaskThe Dewar flask must be of sufficientvolume to completely immerse the main portion of the coolingcoil except for the extremities necessary for receiving anddelivering the
17、sample through the coil.5.4 Erlenmeyer Flasks, 250 mL capacity.5.5 Volumetric Flasks, 1 L capacity. These flasks should beClass A glassware.5.6 Graduated Cylinders100 mL capacity, glasscylinders, graduated in 1 mL or 2 mL divisions.5.7 Microburets, 2.00 mL or 5.00 mL capacity. The mi-croburets shoul
18、d be Class A glassware with 0.01 mL or0.02 mL divisions or less. It is advisable to have the burets tipend equipped with a syringe needle to dispense very smalldrops of titrant.5.8 Sample CylindersThese should be of sufficient vol-ume to give the required amount of sample for testing.Stainless steel
19、 cylinders equipped with needle valves should beused. It is suggested that a 500 mL-capacity cylinder be theminimum size to be used for butadiene.5.9 ThermometerFor observing temperatures below45 C. The Low Cloud and Pour Point Thermometer, con-forming to the requirements for ASTM Thermometer 6C, as
20、prescribed in Specification E1, is satisfactory. Thermometer 6Chas a range from 80 C to +20 C. Temperature measuringdevices that cover the temperature range of interest, such as theASTM 1C thermometer, or liquid-in-glass thermometers,thermocouples, or platinum resistance thermometers that pro-vide e
21、quivalent or better accuracy and precision may be used.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals should beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American C
22、hemical Society wheresuch specifications are available.4Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shal
23、l be understood to mean Type II reagent waterconforming to Specification D1193.6.3 Alcoholic Hydrochloric Acid (0.05 N)Dilute 4.2 mLofconcentrated hydrochloric acid (WarningPoison. Corrosive.May be fatal if swallowed. Liquid and vapor cause severeburns. Harmful if inhaled.) to volume with anhydrous
24、methanolin a 1 L volumetric flask. Use the alcoholic 0.05 N potassiumhydroxide solution to standardize the HCl solution.6.4 Alcoholic Hydroxylamine HydrochlorideDissolve35.0 g of hydroxylamine hydrochloride (WarningMay beirritating to skin, eyes, or mucous membranes. Harmful ifinhaled.) in 3.5 L of
25、anhydrous methanol. (WarningFlammable. Vapor harmful. May be fatal or cause blindness ifswallowed or inhaled. Cannot be made nonpoisonous.)6.5 Alcoholic Potassium Hydroxide (0.05 N)Dissolve3.3 g of potassium hydroxide in anhydrous methanol.(WarningCorrosive. Can cause severe burns or blindness.Evolu
26、tion of heat produces a violent reaction or eruption upontoo rapid mixture with water.) Make to volume with methanolin a 1 L volumetric flask. Standardize against a primarystandard, potassium acid phthalate.6.6 Dry Ice (Carbon Dioxide Solid)(WarningExtremely cold (78.5 C). Liberates heavy gas which
27、maycause suffocation. Contact with skin causes burns or freezing,or both. Vapors may react violently with hot magnesium oraluminum alloys.)6.7 Stoddard SolventConforming to the specificationlisted in Specification D484.(WarningCombustible. Vaporharmful.)6.8 Thymol Blue IndicatorDissolve 0.04 g of th
28、ymol bluein 100 mL of anhydrous methanol. (WarningFlammable.Vapor harmful. May be fatal or cause blindness if swallowed orinhaled. Cannot be made nonpoisonous.)7. Preparation of Apparatus7.1 Dry Ice-Stoddard Solvent Bath Add a sufficient quan-tity of Stoddard solvent into the Dewar flask to ensure t
29、hat thecooling coil will be submerged in the liquid plus dry ice (solidCO2). (WarningSee 6.6 and 6.7.) Carefully add sufficientdry ice to the Stoddard solvent to obtain a temperature of atleast 50 C. (WarningGreat care must be taken during thisstep. Do not add the dry ice all at once, but in small p
30、ieces,especially at the beginning. Wear protective gloves and ad-equate eye protection to prevent any contact with the extremelycold materials.) Attach the sample cylinder containing the4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For sugges
31、tions 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.FIG. 1 ApparatusD4423 10 (2015)
32、2butadiene (WarningExtremely flammable gas under pres-sure. May form explosive peroxides upon exposure to air.Harmful if inhaled. Irritating to eyes, skin, and mucousmembranes. ) to the cooling coil and immerse the coil into theliquid. Support the sample cylinder in a cylinder rack or usinga ring st
33、and and appropriate clamps. Be sure the coil ispositioned so that the delivery tip is free to dispense liquidbutadiene into the Erlenmeyer flasks.After each use, be sure toclean the coils interior with methanol. DO NOT USE AC-ETONE.8. Procedure8.1 Prepare a sample flask by pouring 50 mL of alcoholic
34、hydroxylamine hydrochloride into a 250 mL Erlenmeyer flask.8.2 Prepare a flask for use as a sample blank by pouring50 mL of methanol into a 250 mL Erlenmeyer flask.8.3 Add about 0.5 mL of thymol blue indicator solution toeach flask.8.4 Carefully add 0.05 N alcoholic KOH or alcoholic HCl toeach flask
35、 until matching colors are obtained. The desired coloris a yellow color with a slight, but distinct, orange coloration.It is important that this orange color is present at this point ofthe test. If the color is more yellow at this point, it would beeasy to obtain a result of less than 1 mgkg carbony
36、ls on asample containing over 100 mgkg of carbonyls.8.5 Stopper the flasks with the Bunsen valves. (This keepsthe CO2vapor out of the flasks). Set the flasks on some crusheddry ice for a few minutes to cool the liquid contents. The colorin the flasks may turn more yellow when cold, but this is notsi
37、gnificant at this point. From this step forward, all operationsmust be carried out in a well-ventilated hood.8.6 Cool a 100 mL graduated cylinder by holding it in thecooling bath for a few seconds. Then, when it is cold, collect100 mL 6 1 mL butadiene into the graduated cylinder.Quickly, using a cle
38、an thermometer, measure the samplestemperature to the nearest 1 C. Record this temperature as “T”for use later to obtain the sample weight. Pour this sample intothe sample flask containing the alcoholic hydroxylamine hy-drochloride solution. Replace the Bunsen valve on the flaskand set aside.Again,
39、collect 100 mL 6 1 mLof sample into thegraduated cylinder. Pour this sample into the sample blankflask containing only the methanol. Replace the Bunsen valveand set aside.8.7 Sample and sample blank can be titrated after 15 minwhile cold butadiene is in the flasks. If done, be careful toavoid vigoro
40、us agitation because some of the contents may boilover and be lost. It is advisable to allow as much of thebutadiene as possible to evaporate before titration begins.8.8 Titrate the sample flasks contents back to the originalcoloration, as described in 8.4, by using the alcoholic KOH.Record this val
41、ue as “A.” Set the flask aside in the hood for5 min before pouring out the contents. If it turns red, thecarbonyl concentration may be high or there is contaminationin the flask. Continue the titration until the flasks contents willnot turn red after standing 5 min.8.9 Titrate the sample blank flask
42、s contents. If the solutionis red, use the standard KOH solution. If it is yellow, use thestandard HCl solution. In either case, unless the sample blankscontents are still at the original coloration, titrate with theappropriate titrant back to the same, original coloration asdescribed in 8.4. Record
43、 this value as “E.”9. Calculation9.1 Calculate as follows when the sample has no free acid orfree base:mg/Kg carbonyls as acetaldehyde! 5 A 3 Nb 344050/V 3 D (1)where:A = alcoholic KOH titration, mL,Nb = normality of KOH solution,V = sample volume, mL, andD = butadiene density at temperature T (foun
44、d by usingTable 1).9.2 Calculate as follows when the sample has free acid:mg/Kg carbonyls as acetaldehyde! 5 A 2 Bb! 3 Nb 344050/V 3 D(2)where:Bb = alcoholic KOH used for the sample blank, mL.9.3 Calculate as follows when the sample has free base:mg/Kg carbonyls as acetaldehyde! 5 A 3 Nb!1Ba 3 Na!34
45、4050/V 3 D (3)where:Na = normality of alcoholic HClBa = alcoholic HCl used for the sample blank, mL10. Precision and Bias10.1 PrecisionThe precision of this test method as deter-mined by statistical examination of interlaboratory results is asfollows:10.1.1 RepeatabilityThe difference between two te
46、st re-sults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialwould, in the long run, in normal and correct operation of thetest method, exceed the following value in only one case intwenty, where X = the average of the two test result
47、s:14%ofXTABLE 1 Density of Butadiene at Various TemperaturesNOTE 1These data may be used in a graphical manner for betterinterpolation between data points.Temperature, C Density, g/mL45 0.695840 0.690335 0.684830 0.679325 0.673720 0.668115 0.662510 0.65685 0.65100 0.6452D4423 10 (2015)310.2 Reproduc
48、ibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would, inthe long run, in the normal and correct operation of the testmethod, exceed the following value in only one case in twenty,where X =
49、average of two test results:88%ofX10.3 BiasSince there is no accepted reference material fordetermining the bias for the procedure in this test method formeasuring carbonyls, no statement on bias is being made.11. Keywords11.1 butadiene; C4hydrocarbons; carbonyls; titrationASTM 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
