1、Designation: D2384 83 (Reapproved 2014)Standard Test Methods forTraces of Volatile Chlorides in Butane-Butene Mixtures1This standard is issued under the fixed designation D2384; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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. Scope1.1 These test methods cover the determination of the totalvolatile organic chlorides in concentrations from 10 to1
3、00 ppm in butane-butene mixtures. The amperometric finishis not directly applicable in the presence of other substancesthat combine with silver ion or oxidize chloride ion in diluteacid solution. Bromides, sulfides, ammonia, tobacco smoke,and more than 25 g of hydrogen peroxide in the test solutioni
4、nterfere in the spectrophotometric procedure.1.2 Dissolved sodium chloride is not quantitatively deter-mined using these test methods.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to addr
5、ess all of thesafety 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. Specific warningstatements are given in Sections 5, 8, 1
6、1, 14, 19, and AnnexA1.2. Referenced Documents2.1 ASTM Standards:2D329 Specification for AcetoneD1266 Test Method for Sulfur in Petroleum Products (LampMethod)3. Summary of Test Methods3.1 Combination Test MethodsEither the lamp or oxy-hydrogen test method may be used for combustion.NOTE 1Lamp combu
7、stion is readily applicable to multiple testing.Although an oxy-hydrogen burner does not lend itself to multiple testing,it affords much more rapid analysis for a single sample than does the lampcombustion.3.1.1 Lamp CombustionThe sample is burned in an atmo-sphere of carbon dioxide and oxygen or in
8、 purified air; thehalogen-containing combustion products are absorbed in dilutesodium carbonate solution.3.1.2 Oxy-Hydrogen CombustionThe sample is burned inan oxy-hydrogen atomizer burner, and the combustion productsare absorbed in a dilute solution of sodium carbonate.3.2 FinishesEither the ampero
9、metric titration or spectro-photometric finish may be used for the chloride ion determi-nation.3.2.1 Amperometric TitrationThe chloride ion in aqueoussolution is titrated amperometrically with standard silver ni-trate solution, using a saturated calomel electrode as referenceelectrode. The diffusion
10、 currents are plotted against the corre-sponding volumes of silver nitrate solution used; the end pointis taken as the intersection of the two straight-line portions ofthe curve.3.2.2 Spectrophotometric FinishChloride ion in the ab-sorber solution is determined by reaction with mercuric thio-cyanate
11、 to release thiocyanate, which forms a reddish orangecomplex with Fe+. The intensity of the color is measured at460 nm with a spectrophotometer or filter photometer.4. Significance and Use4.1 These test methods are used to determine trace amountsof volatile chlorides in butane-butene mixtures. Such
12、informa-tion is valuable in cases where chloride is deleterious in the useof this product; also, chloride contributes to corrosion prob-lems in processing units in instances where further processingof this material is involved.5. Purity of Reagents5.1 Purity of ReagentsReagent grade chemicals shall
13、beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and
14、Lubricants and are the direct responsibilityof Subcommittee D02.D0.04 on C4 Hydrocarbons.Current edition approved May 1, 2014. Published July 2014. Originally approvedin 1965. Last previous edition approved in 2009 as D2384 83(2009). DOI:10.1520/D2384-83R14.2For referenced ASTM standards, visit the
15、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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Uni
16、ted States1where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 References to water shall be understood to meanchloride-free distilled
17、 or deionized water.5.3 (WarningIn view of the common occurrence ofchloride in reagents and laboratory air, special care must betaken during preparation and storage of reagents to avoidcontamination. They should be isolated from other reagentsand used solely for these methods.Ablank determination mu
18、stbe performed each time a reagent is changed to ensure that itis not contaminated with chloride.It is also imperative that all glassware used in this determi-nation be cleaned thoroughly and rinsed four times withchloride -free distilled or deionized water. Utmost caution mustbe taken during the an
19、alysis to prevent contamination fromchlorides.)6. Sampling6.1 Steam and dry a 10 to 25-mL corrosion-resistant metalsample cylinder having a 450-psi (3100 kPa) working pressureand equipped with a needle valve outlet at each end.6.2 Pressure the prepared cylinder with dry hydrogen to20 psig (137.5 kPa
20、 gage) to afford a gas cushion preventingrupture due to liquid expansion on increase of temperature.6.3 Obtain a liquid sample from the purged sample line,filling the upright cylinder through the bottom needle valve,keeping the top valve closed. Do not purge the sample cylinder.LAMP COMBUSTION TEST
21、METHOD7. Apparatus7.1 ASTM Lamp AssemblyUse the apparatus specified inTest Method D1266, including the liquefied petroleum gasburner assembly.8. Reagents8.1 Use the necessary reagents and materials specified inTest Method D1266, in addition to the absorber solution asdescribed in 8.3.8.2 Hydrogen (W
22、arningExtremely flammable (liquefied)gas under pressure. See Annex A1.1.)8.3 Sodium Carbonate Absorbent (2 g/L) Dissolve 2.0 gof anhydrous sodium carbonate (Na2CO3) in water and diluteto a litre with water.9. Procedure9.1 Prepare the combustion apparatus as described in Sec-tion 7 of Test Method D12
23、66, Preparation of Apparatus, using35 mL of Na2CO3solution to charge the absorber.9.2 Weigh the vessel containing the sample to the nearest0.1 g. Support the sample vessel in an upright position so thatthe sample is burned from the gaseous phase. Connect thesample vessel to the auxiliary corrosion-r
24、esistant regulatingvalve by means of corrosion-resistant metal tubing (Fig. 1)(Note 2). Connect the bottom valve of the sample vessel to theregulated hydrogen supply. By means of short lengths ofchloride-free rubber tubing, connect the auxiliary valve outletto the side inlet of the gas burner and th
25、e lower inlet of the gasburner (Test Method D1266, Annex A3, Apparatus Detail, Fig.5) to the burner manifold.NOTE 2For steady burning, it may be necessary to surround theauxiliary valve with a heat-exchanger system. A convenient means iswinding insulated heating wire, having a resistance of 40 to 60
26、 , aroundthe auxiliary valve and connecting it to a suitable rheostat.Another means3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for L
27、aboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Diagrammatic Sketch of Butane-Butene Heat Exchange SystemD2384 83 (2014)2is to place the regulating valve in a suitable metal b
28、eaker and cover thevalve body with water maintained at 60 to 80C.9.3 Open the valve on the sample vessel; then open theauxiliary valve to allow a small stream of vapor to escape.Quickly light the burner. Adjust the flow of CO2-O2mixtureand the sample so that the flame is approximately 35 mm highand
29、clear blue in color; this color is reached just beyond thepoint at which a yellow color shows at the tip of the flame.Insert the burner into the chimney and readjust the flame ifnecessary. When the sample has burned almost to completion,open the valve on the bottom of the sample vessel and flush the
30、residual sample from the cylinder chamber by passing hydro-gen through the bottom valve for several minutes.9.4 When all of the residual material has been flushed fromthe sample vessel, turn off the hydrogen and close the valves onthe sample vessel. Disconnect the hydrogen flushing line andthe line
31、to the heated auxiliary valve and weigh the samplevessel to the nearest 0.1 g. Draw the combustion atmospherethrough one absorber of a set to serve as a blank on the purityof this atmosphere. Rinse the chimneys and spray traps withwater and add the rinsings to the absorbers.9.5 Proceed in accordance
32、 with either Section 16 or 21.OXY-HYDROGEN COMBUSTION TEST METHODALTERNATIVE TEST METHOD10. Apparatus10.1 Oxy-Hydrogen Burner4A flow diagram of a typicalapparatus is shown in Fig. 2. The apparatus shall consist ofthree parts: atomizer-burner, combustion chamber, and receiverwith spray trap. A blowou
33、t safety port in the combustionchamber is desirable. The remainder of the apparatus shallconsist of a steel support stand with the necessary needlevalves and flow meters for precise control of air, oxygen,hydrogen, and vacuum.10.2 Vacuum Pump, having a capacity of at least 1200 L/h,and protected fro
34、m corrosive fumes by suitable traps.11. Reagents and Materials11.1 Hydrogen (WarningExtremely flammable (lique-fied) gas under pressure. See Annex A1.1.)11.2 Oxygen (WarningOxygen vigorously acceleratescombustion. See Annex A1.2.)11.3 Sodium Carbonate, Absorbent (2g/L)See 8.3.12. Procedure12.1 Follo
35、w the manufacturers instructions for preparingand operating the apparatus. Place 50 mL of the Na2CO3absorbent in the absorber. Burn all of the sample from the gasphase of the cylinder (Fig. 1). (Warning Extremely flam-mable (liquefied) gas under pressure. See Annex A1.1.). Flushthe residual gases fr
36、om the cylinder chamber by passinghydrogen through the bottom valve for several minutes, burn-ing the flushed gases.)12.2 When combustion is completed, rinse all water-cooledportions of the apparatus and the spray trap with a spray ofwater. Collect all rinsings in the absorbent.12.3 Proceed in accor
37、dance with either Section 16 or 21.12.4 Prepare a blank by placing 50 mL of the Na2CO3absorbent in the absorber. Operate the apparatus for the sameperiod of time, under the same conditions that were used forthe combustion of the sample, but without a sample and thesample inlet closed to the atmosphe
38、re. Burn approximately thesame volume of hydrogen as was used to flush the samecylinder. When combustion of the hydrogen is complete, rinseall water-cooled portions of the apparatus and the spray trapwith a spray of water. Collect all rinsings in the absorbent.Proceed as in 12.3.AMPEROMETRIC TITRATI
39、ON FINISH13. Apparatus13.1 Potentiometer-Galvanometer Assembly, capable of ap-plying a cell potential up to 3 V with an accuracy of 1 % of fullscale, and capable of indicating the cell current by means of agalvanometer having a sensitivity of 0.005 to 0.008 A/mmscale division. A multiposition galvan
40、ometer shunt for adjust-ment of current measurement sensitivity should also be pro-vided; shunt ratios to give sensitivities of approximately 0.05to 0.08, and 0.10 to 0.16 A/mm should be included.4The Wickbold Burner Apparatus obtainable from the Atlas Instrument Co.,8902 E. 11th St., Tulsa, OK, or
41、the Richfield Burner Apparatus obtainable from theGreiner Glass Blowing Laboratories, 3604 E. Medford St., LosAngeles, CA90034,has been found suitable for this purpose. If you are aware of alternative suppliers,please provide this information to ASTM International Headquarters. Your com-ments will r
42、eceive careful consideration at a meeting of the responsible technicalcommittee,1which you may attend.1Atomizer-burner 4Three-way stopcock2Sample tube 5Absorber3Combustion chamber 6Spray trapFIG. 2 Flow Diagram of a Typical Oxy-Hydrogen CombustionApparatusD2384 83 (2014)313.2 Titration AssemblyAn ap
43、paratus similar to thatshown in Fig. 3, consisting of a rotating (600 rpm) platinumelectrode, a saturated calomel reference electrode with saltbridge, a means of blanketing the solution with nitrogen, and aholder for a 10-mL buret.13.3 Calomel Electrode, constructed as shown in Fig. 3.13.4 Platinum
44、Electrode, rotating-hook type. A suitableelectrode may be constructed as follows: Seal a platinum wire0.03 to 0.05 in. (0.76 to 1.3 mm) in diameter and 0.75 to 1.0 in.(19.1 to 25.4 mm) long into the end of a 6-mm outside diametersoft glass tube that has been shaped into a stirrer blade. Bendthe exte
45、nding platinum wire upwards at its midpoint to form anangle of 90. Place a few drops of mercury in the glass tube andmake electrical contact between the mercury and the connec-tion on the amperometric titrator with a piece of copper wire(insulate the exposed wire to prevent shorting).13.5 BuretA 10-
46、mL semi-micro buret, with the tip con-structed so as to be able to dip below the surface of the solutionbeing titrated.14. Reagents14.1 Acetone (99.5 %) (WarningExtremely flammable.Vapor may cause fire. See Annex A1.3.)Refined acetoneconforming to Specifications D329.14.2 Agar SolutionDissolve2gofag
47、ar-agar powder in100 mL of hot water (80 to 100C) containing 20 g ofpotassium nitrate (KNO3).14.3 Bromthymol Blue Indicator SolutionDissolve 0.10 gof the solid indicator in 100 mL of hot water, cool, and add 1mL of chloroform as a preservative. Discard the solution whenit is 1 week old.NOTE 3Remove
48、possible objectionable amounts of chloride bypassing the solution through an ion-exchange resin in the hydroxyl form.Neutralize the resulting alkaline solution to the bromthymol blue end pointby titration with HNO3(3 + 97).14.4 Chloride, Standard Solution (10 g Cl/mL)Dilute asuitable volume of 1 + 1
49、0 assayed hydrochloric acid to obtaina solution containing 10 g Cl/mL.14.5 Gelatin Solution (10 g/L)Dissolve1gofgelatin in100 mL of hot water and add 1 mL of chloroform as apreservative. Discard the solution when it is 1 week old.14.6 Hydrogen Peroxide SolutionPrepare by diluting 1volume of concentrated hydrogen peroxide solution (H2O2,30 %) with 4 volumes of water. Store in a dark-coloredglass-stoppered bottle.14.7 Mercury-Calomel MixturePrepare a mixture of mer-cury and calomel (mercurous chloride, Hg2Cl2) by vigorouslyFIG. 3 Sch
