Carnauba Wax
» Carnauba Wax is obtained from the leaves of Copernicia cerifera Mart. (Fam. Palmae).
Packaging and storage— Preserve in well-closed containers.
Melting range, Class II 741: between 80 and 86.
Acid value— Weigh accurately 3 g into a 250-mL flask attached to a reflux condenser, add 50 mL of a mixture of isopropyl alcohol and toluene (5:4), and boil gently until the wax is completely dissolved. Remove the flask from the condenser, add about 1 mL of phenolphthalein TS, and immediately titrate with 0.5 N alcoholic potassium hydroxide VS to a faint, reddish yellow color. [note—Do not allow solution to cool; titrate at warm temperature after refluxing.] Calculate the acid value as the number of mg of potassium hydroxide required to neutralize the free acids in 1 g of Carnauba Wax. The acid value so obtained is between 2 and 7.
Saponification value 401 To the solution from the test for Acid value add 15.0 mL of 0.5 N alcoholic potassium hydroxide VS, reflux for 3 hours, and titrate the excess alkali with 0.5 N hydrochloric acid VS to a yellow-amber color. Perform a blank determination (see Residual Titrations under Titrimetry 541). The saponification value is the summation of the ester value so obtained and the Acid value, and it is between 78 and 95.
Residue on ignition 281 Heat 2 g in an open porcelain or platinum dish over a flame: it volatilizes without emitting an acrid odor. Ignite: the weight of the residue does not exceed 5 mg. Not more than 0.25% is found.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Hong Wang, Ph.D.
(EM205) Excipient Monographs 2
USP32–NF27 Page 1377
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.