Authorized USP Pending Monograph Version 1 BRIEFING Ictasol. This monograph was posted on the USP Website as a Draft USP Pending Monograph, and has been available for public comment for more than 90 days. No comments were received. The SM3 Expert Committee has approved the monograph as an Authorized USP Pending Monograph. Description and Solubility: Light to dark brown liquid with characteristic odor. Very soluble in water and in glycerin. Partially soluble in alcohol and in ether. (SM3: F. Mao.) Correspondence Number—C86998 Ictasol / 1 using photometric indication at a wavelength of 490 nm. Perform a blank determination, and make any necessary correction. Each mL of 0.01 N Ba(ClO4)2 VS is equivalent to 0.1603 mg of total sulfur. Calculate the percentage of total sulfur in the portion of Ictasol taken: Result = (V × N × F × 100)/W V = sample titrant volume, corrected for blank determination (mL) N = titrant normality (N) F = equivalence factor [16.03 mg of total sulfur/mEq of Ba(ClO4)2] W = weight of Ictasol (mg) Acceptance criteria: NLT 10.5% • TOTAL SODIUM Calculate the percentage of total sodium in the portion of Ictasol taken: Ictasol . Result = (WU/WS) × 100 v.1 Authorized May 1, 2011 Ictasol [1340-06-3]. DEFINITION Ictasol is obtained by the destructive distillation of certain bituminous schists, mild sulfonation of a volatile fraction of the distillate, and neutralization of the product with sodium hydroxide solution. Ictasol yields NLT 10.5% of total sulfur (S), and NLT 3.0% and NMT 4.9% of total sodium (Na). IDENTIFICATION • A. RESINOUS PRECIPITATE FORMATION Sample solution: 100 mg/mL in water Analysis: To 2 mL of the Sample solution, add 2 mL of hydrochloride acid. A resinous precipitate is formed. Decant the supernatant liquid. The precipitate is partially soluble in ether. • B. IDENTIFICATION TESTS—GENERAL, Sodium 〈191〉 Sample solution: 100 mg/mL in water Analysis: To 2 mL of the Sample solution, add 2 mL of 15% potassium carbonate, and heat to boiling. No precipitate is formed. Add 4 mL of potassium pyroantimonate TS, and heat to boiling. Allow to cool in ice water and, if necessary, rub the inside of the test tube with a glass rod. A dense precipitate is formed. ASSAY • TOTAL SULFUR (See Oxygen Flask Combustion 〈471〉.) Analysis: Wrap and flatten a small piece of cotton around one end of ash-free paper strip (approximately 35 mm × 3 mm). Place the cotton end of the ash-free paper strip in the platinum gauze specimen holder (with the other end of the paper strip pointed towards the stopper). Weigh 10–15 mg of Ictasol in the cotton. Use the ash-free paper strip for ignition. Use 30 mL of an aqueous solution containing 3% hydrogen peroxide as the absorbing liquid. After the combustion and cooling, shake the flask to solubilize the combustion products in the solution. Transfer the contents of the flask quantitatively with 60 mL of 2-propanol into a beaker. Add 0.5 mL of a solution containing 0.2% thorin indicator, and place the beaker in an ultrasonic bath for degassing. Titrate with 0.01 N Ba(ClO4)2 VS WU = weight of total sodium (g), calculated from the test for Residue on Ignition where 0.1 g of residue corresponds to 0.03237 g of sodium WS = weight of Ictasol (g) Acceptance criteria: 3.0%–4.9% IMPURITIES Inorganic Impurities • RESIDUE ON IGNITION 〈281〉: NMT 15.0% • LIMIT OF SODIUM SULFATE Sample: 2 g of Ictasol Analysis: Dissolve the Sample in 100 mL of water. Mix this solution with 80 mL of 25 mg/mL cupric chloride in water, and dilute with water to 200 mL. Shake and filter. Heat 100 mL of the filtrate to almost boiling, add 1 mL of hydrochloric acid and 5 mL of 61 mg/mL barium chloride solution dropwise, and heat in a water bath. Filter, wash the precipitate with water, dry, and ignite at 600° until two successive weighings do not differ by more than 0.2% of the mass of the residue. Each g of the residue is equivalent to 0.6086 g of sodium sulfate (Na2SO4). Calculate the percentage of sodium sulfate in the portion of Ictasol taken: Result = (WU/WS) × 200 WU = weight of sodium sulfate (g) WS = weight of Ictasol (g) Acceptance criteria: NMT 1.1% SPECIFIC TESTS • LOSS ON DRYING 〈731〉: Dry a sample at 80° for 8 h, and continue the drying at 100° to constant weight: it loses NLT 44.0% and NMT 50.0% of its weight. ADDITIONAL REQUIREMENTS • PACKAGING AND STORAGE: Preserve in well closed containers, and store at controlled room temperature. This monograph has been developed under USP‘s Pending Monographs Guideline and is not a USP–NF monograph. http://www.usp.org 2011 The United States Pharmacopeia. All Rights Reserved.