ASTM D5351-93(R2021) pdf free download

ASTM D5351-93(R2021) pdf free download.Standard Test Method for Determination of Organically Combined Sulfuric Anhydride by Extraction Titration, Test Method B
1. Scope
1.1 This test method covers the determination of the organi- cally combined sulfuric anhydride existing in a sample of sulfated oil by extracting the undecomposed sulfated fat and other fatty matter over an acidulated, concentrated salt solution, boiling the residue with sulfuric acid after evaporat- ing the solvent, and titrating the products of reaction. This test method is applicable only to sulfated oils that split off their combined SO 3 upon boiling with mineral acids, including samples containing sodium acetate or other compounds that cannot be accurately titrated in water solution with methyl orange as the indicator. This test method was derived from Test Methods D500, Sections 20 through 24, and ALCA Method H-43. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for information only. 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 ofregulatory limitations prior to use. 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.
4. Apparatus
4.1 The apparatus required consists ofa glass flask provided with a glass stopper and an air condenser. The connection between the flask and the condenser shall be a ground joint. Perforated glass beads shall be used to prevent bumping. 4.1.1 Flask, an Erlenmeyer flask (Fig. 1) made of borosili- cate glass, having a capacity of approximately 300 mL, and provided with a glass stopper. 4.1.2 Condenser—The condenser required consists of a glass tube, 915 mm (36 in.) in length, and 8 mm ( 5 ⁄ 16 in.) in outside diameter. The lower end of the tube shall be flared and ground to fit the mouth of the Erlenmeyer flask. 4.1.3 Glass Beads, perforated glass beads, made of chemi- cally resistant glass, approximately 4 mm ( 5 ⁄ 32 in.) in diameter. Before using, the glass beads shall be boiled thoroughly in several portions of water or until the wash water reacts neutral to methyl orange indicator.
5. Reagents
5.1 Ethyl Ether: 5.2 Methyl Orange Indicator Solution (1 g/L)—Dissolve 0.1 g of methyl orange in 100 mL of water. 5.3 Sodium Chloride (NaCl), solid. 5.4 Sodium Hydroxide, Standard Solution (1 N)— Accurately prepare and standardize a 1 N sodium hydroxide (NaOH) solution. Express the strength or concentration of the solution as milligrams of KOH per millilitre; 1 mL of 1 N NaOH solution is equivalent to 56.1 mg of KOH. 5.5 Sodium Hydroxide, Standard Solution (0.5 N)— Accurately prepare and standardize a 0.5 N NaOH solution.Express the strength of the solution as milligrams of KOH per millilitre; 1 mL of 0.5 N NaOH solution is equivalent to 28.05 mg of KOH. 5.6 Sulfuric Acid (1 + 19)—Carefully mix one volume of concentrated sulfuric acid (H 2 SO 4 , sp gr 1.84) into 19 volumes of water while stirring. 5.7 Sulfuric Acid Standard (0.5 N)—Accurately prepare and standardize as 0.5 N sulfuric acid (H 2 SO 4 ) solution. Express the strength ofthe solution as milligrams ofKOH per millilitre; 1 mL of 0.5 N H 2 SO 4 is equivalent to 28.05 mg of KOH. 6. Procedure 6.1 The procedure consists of isolating and purifying the fatty matter as it exists in the original oil by dissolving the sample in a solvent, acidifying and washing with saturated brine, and determining the increase in acidity upon boiling the isolated product with sulfuric acid. This increase in acidity is designated as F. 6.1.1 Separation ofPurified Oil—Weigh 5 g to 10 g of the sample, depending upon the concentration of the fatty matter, into a 250-mL separatory funnel containing 50 mL of concen- trated NaCl solution, some solid NaCl, five drops of methyl orange indicator solution, and 50 mL of ether. Shake the mixture and neutralize with H 2 SO 4 (1 + 19) until the lower layer is distinctly pink (about 0.2 mL in excess). Highly sulfated oils at this stage may form three layers instead of two. In such cases, use a fat solvent consisting of a mixture of two parts of ether and one part of alcohol. Allow the mixture in the separatory funnel to settle for at least 5 min, draw off the lower layer into another separatory funnel, and wash the ether layer with 25-mL portions of NaCl solution until practically neutral to methyl orange, that is, until one drop of 0.5 N NaOH solution turns the wash water strongly alkaline.