ASTM D3444-00(R2020) pdf free download

ASTM D3444-00(R2020) pdf free download.Standard Test Method for Total Acid Number of Trichlorotrifluoroethane
1. Scope
1.1 This test method covers the determination of total acidity in trichlorotrifluoroethane and other halocarbons that are liquid at room temperature. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 6. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
5. Reagents
5.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Commit- tee on Analytical Reagents of the American Chemical Society, where such specifications are available. 3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 5.2 Purity ofWater—Unless otherwise indicated, references to water shall be understood to mean halide-free distilled water. 5.3 Isopropyl Alcohol. 5.4 Phenolphthalein Indicator Solution (0.05 g in 100 mLof isopropyl alcohol). 5.5 Potassium Acid Phthalate, U.S. National Bureau of Standards primary standard. Dry this chemical in a 120 °C oven for several hours prior to use. Store the dry chemical in a desiccator. 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- mately 1 L of anhydrous isopropyl alcohol in a 2 L Erlenmeyer flask. Boil the mixture gently for 5 to 10 min, stirring to prevent the solids from forming a cake on the bottom. Add at least 2 g of barium hydroxide [Ba(OH) 2 ] and boil again gently for 5 to 10 min. Cool to room temperature. Allow to stand for several hours and filter the supernatant liquid through a fine sintered glass or porcelain filtering funnel. Avoid unnecessary exposure to CO 2 during filtration. Store the solution out of contact with cork or rubber. Protect the solution from CO 2 by a guard tube containing carbon dioxide adsorbent. Standardize against pure potassium acid phthalate in about 25 mL of CO 2 -free water using phenolphthalein to detect the end point.
6. Hazards
6.1 Trichlorotrifluoroethane removes natural oils from skin. Avoid skin contact. The solvent is not flammable and has a threshold limit value of 1000 ppm by volume in air. See the manufacturer’s MSDS. 6.2 Isopropyl alcohol is flammable, and has a threshold limit value of 400 ppm by volume in air. See the manufactur- er’s MSDS. 6.3 Potassium hydroxide is corrosive to body tissue. Avoid contact with the solid and its solution. Should this chemical contact the person, immediately flush the affected area with copious amounts of water. See the manufacturer’s MSDS.
7. Procedure
7.1 For sample analysis, add 50 mL of isopropyl alcohol to a 250 ml Erlenmeyer flask, add 5 drops of phenolphthalein indicator solution and titrate to a pink end point with alcoholic KOH solution. 7.1.1 Swirl flask contents gently during titration. The end point should last for 10 to 15 s. Stopper the flask until the sample is added to minimize CO 2 contamination. 7.2 Pour a weighed sample (about 50.00 6 0.02 g) into the flask containing the pretitrated alcohol. 7.3 Titrate the sample with the standard alcoholic KOH solution to a 15 s pink end point. Record the amount of titrant required. 7.4 For standardization of 0.01 NKOH in isopropyl alcohol, proceed as follows: 7.4.1 Weigh (60.0001 g) 0.142 6 0.005 g of dry (National Bureau of Standards) primary standard potassium acid phtha- late into a 1 L volumetric flask containing about 500 mL of deionized CO 2 -free water, then stopper the flask. 7.4.2 Swirl the flask to dissolve the potassium acid phtha- late.