(eye'' soe proe' pil al' ka hol).
» Isopropyl Alcohol contains not less than 99.0 percent of C3H8O.
Packaging and storage Preserve in tight containers, remote from heat.
USP Reference standards 11
Identification, Infrared Absorption 197F.
Specific gravity 841: between 0.783 and 0.787.
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 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%).
Assay Inject about 5 µL of Isopropyl Alcohol into a suitable gas chromatograph, equipped with a thermal conductivity detector. Under typical conditions, the gas chromatograph contains a 1.8-m × 6.4-mm (OD) 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. Calculate the percentage of C3H8O in the Isopropyl Alcohol by dividing the area under the isopropyl alcohol peak by the sum of the areas under all of the peaks observed, and multiplying by 100.
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USP35NF30 Page 3577Pharmacopeial Forum: Volume No. 33(6) Page 1182