Azeotropic Isopropyl Alcohol
» Azeotropic Isopropyl Alcohol contains not less than 91.0 percent and not more than 93.0 percent of isopropyl alcohol, by volume, the remainder consisting of water.
Packaging and storage— Preserve in tight containers, remote from heat.
Identification— The IR absorption spectrum of a thin film of it exhibits a strong broad band at 3.0 µm; a strong region of absorption between 3.35 µm and 3.5 µm, with its highest peak at 3.36 µm, and others at 3.41 µm and 3.47 µm; many weak peaks between 3.6 µm and 6.0 µm, among the most noticeable being those at 3.68 µm, 3.77 µm, 3.97 µm, 4.17 µm, and 5.26 µm; a broad band at about 6.2 µm; a strong region of absorption between 6.7 µm and 7.8 µm, the most prominent features being the peaks at 6.80 µm, 7.09 µm, 7.25 µm (the highest), 7.46 µm, and 7.63 µm; a strong region of absorption between 8.5 µm and 9.2 µm, peaking at 8.6 µm, 8.85 µm, and 9.0 µm; and strong peaks at 10.5 µm and at 12.3 µm.
Specific gravity 841: between 0.815 and 0.810, indicating between 91.0% and 93.0% by volume of C3H8O.
Refractive index 831: between 1.376 and 1.378 at 20.
Acidity— To 50 mL in a suitable flask add 100 mL of carbon dioxide-free water. Add 2 drops of phenolphthalein TS, and titrate with 0.020 N sodium hydroxide to a pink color that persists for 30 seconds: not more than 0.70 mL of 0.020 N sodium hydroxide is required for neutralization.
Limit of nonvolatile residue— Evaporate 50 mL of Isopropyl Alcohol in a tared porcelain dish on a steam bath to dryness, and heat at 105 for 1 hour: the weight of the residue does not exceed 2.5 mg (0.005%).
Volatile impurities— Inject about 5 µL into a suitable gas chromatograph, equipped with a thermal conductivity detector. Under typical conditions, the gas chromatograph contains a 6.4-mm × 1.8-m stainless steel column packed with 10% liquid phase G20 on support S1A, the column is maintained at 55, and helium is used as the carrier gas at a flow rate of 45 mL per minute. Relative retention times of some of the possible components, when present, are: air at 0.09, diethyl ether at 0.14, diisopropyl ether at 0.17, acetone at 0.37, isopropyl alcohol at 1.00, 2-butanol at 1.64, n-propyl alcohol at 1.86, and water at 3.14. Divide the area under the isopropyl alcohol peak by the sum of the areas under all of the peaks observed, excluding the water peak: the quotient is not less than 0.99.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Behnam Davani, Ph.D., M.B.A.
Senior Scientific Liaison
(SM12010) Monographs - Small Molecules 1
USP35–NF30 Page 3578