1、Designation:D344400(Reapproved 2015)Standard Test Method forTotal Acid Number of Trichlorotrifluoroethane1This standard is issued under the fixed designation D3444;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revi
2、sion.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 totalacidity in trichlorotrifluoroethane and other halocarbons thatare liquid at room t
3、emperature.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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 to establi
4、sh appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in Section 6.2.Summary of Test Method2.1 The total acidity of the solvent is determined by titrationwith standard alcoholic potassium hydro
5、xide solution usingphenolphthalein solution as the indicator.3.Significance and Use3.1 This test method determines the total acidity of trichlo-rotrifluoroethane by titration with alcoholic potassium hydrox-ide using phenolphthalein for an indicator.3.2 This test method can be used to develop produc
6、tion andpurchasing specifications.4.Apparatus4.1 Buret,2-mLin 0.01-mLsubdivisions,self-leveling,with1000-mL reservoir.4.2 Vinyl Tubing.24.3 Two Indicating Carbon Dioxide Absorbent Tubes,3050mesh.5.Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indica
7、ted,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 purity to permit
8、 its use without lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean halide-free distilled water.5.3 Isopropyl Alcohol.5.4 Phenolphthalein Indicator Solution(0.05 g in 100 mLofisopropyl alcohol).5.5 Potassium Acid Ph
9、thalate,U.S.National Bureau ofStandards primary standard.Dry this chemical in a 120C ovenfor several hours prior to use.Store the dry chemical in adesiccator.5.6 Potassium Hydroxide Pellets.5.7 Potassium Hydroxide Solution in Isopropyl Alcohol(0.01 N)Add approximately 1 g of solid KOH to approxi-mat
10、ely 1 L of anhydrous isopropyl alcohol in a 2-L Erlenmeyerflask.Boil the mixture gently for 5 to 10 min,stirring toprevent the solids from forming a cake on the bottom.Add atleast 2 g of barium hydroxide Ba(OH)2 and boil again gentlyfor 5 to 10 min.Cool to room temperature.Allow to stand forseveral
11、hours and filter the supernatant liquid through a finesintered glass or porcelain filtering funnel.Avoid unnecessaryexposure to CO2during filtration.Store the solution out ofcontact with cork or rubber.Protect the solution from CO2bya guard tube containing carbon dioxide adsorbent.Standardizeagainst
12、 pure potassium acid phthalate in about 25 mL ofCO2-free water using phenolphthalein to detect the end point.6.Hazards6.1 Trichlorotrifluoroethane removes natural oils from skin.Avoid skin contact.The solvent is not flammable and has athreshold limit value of 1000 ppm by volume in air.See themanufac
13、turers MSDS.1This test method is under the jurisdiction of ASTM Committee D26 onHalogenated Organic Solvents and Fire Extinguishing Agents and is the directresponsibility of Subcommittee D26.04 on Test Methods.Current edition approved June 1,2015.Published June 2015.Originallyapproved in 1975.Last p
14、revious edition approved in 2010 as D3444 00(2010)1.DOI:10.1520/D3444-00R15.2Tygon has been found satisfactory.An equivalent may be used.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the Amer
15、ican 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.U
16、nited States1 6.2 Isopropyl alcohol is flammable,and has a thresholdlimit value of 400 ppm by volume in air.See the manufactur-ers MSDS.6.3 Potassium hydroxide is corrosive to body tissue.Avoidcontact with the solid and its solution.Should this chemicalcontact the person,immediately flush the affected area withcopious amounts of water.See the manufacturers MSDS.7.Procedure7.1 For sample analysis,add 50 mL of isopropyl alcohol toa 250-ml Erlenmeyer flask,add 5 drops of phenolphthaleinindicator so
