Fully Hydrogenated Rapeseed Oil

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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CAS RN®: 84681-71-0.

1 DEFINITION

Fully Hydrogenated Rapeseed Oil is the product obtained by refining and hydrogenating oil obtained from the seeds of Brassica napus and

Brassica campestris (Fam. Cruciferae). The product is a mixture of triglycerides in which the fatty acid composition is a mixture of saturated fatty acids.

2 IDENTIFICATION

A. It meets the requirements of the test for Fats and Fixed Oils, Fatty Acid Composition〈401〉.

3 IMPURITIES

3.1 Alkaline Impurities

Sample solution: Prepare a mixture of 2.0 g of Fully Hydrogenated Rapeseed Oil, 1.5 mL of alcohol, and 3.0 mL of toluene. Dissolve by gentle heating.

Analysis: To the Sample solution add 0.05 mL of bromophenol blue TS, and titrate with 0.01 N hydrochloric acid to a yellow endpoint.

Acceptance criteria: NMT 0.4 mL of 0.01 N hydrochloric acid is required.

Residue on Ignition 〈281〉: NMT 0.5%, when a 5-g sample of Fully Hydrogenated Rapeseed Oil is ignited at an ignition temperature of 800 ± 25°

3.2 Limit of Nickel

Sample solution: Weigh 5.0 g of Fully Hydrogenated Rapeseed Oil into a previously tared platinum or silica crucible. Cautiously heat the substance, and introduce into it a wick formed from twisted ashless filter paper. Ignite the wick. When the substance ignites, stop heating.

After combustion, ignite in a muffle furnace at about 600°. Continue the incineration until white ash is obtained. After cooling, transfer theresidue, with the aid of two 2-mL portions of diluted hydrochloric acid, to a 25-mL volumetric flask. Add 0.3 mL of nitric acid, and dilute with water to volume. 

Standard stock solution: 0.2 μg/mL of nickel prepared from nickel standard solution TS and water. Prepare immediately before use.

Standard solutions: Into three identical 10-mL volumetric flasks introduce 1.0, 2.0, and 4.0 mL of Standard stock solution, respectively. To each flask add a 2.0-mL portion of the Sample solution, and dilute with water to volume.

3.3 Instrumental conditions

(See Atomic Absorption Spectroscopy 〈852〉.)

Mode: Atomic absorption spectrophotometer equipped with a graphite furnace

Absorbance: 232.0 nm

Lamp: Nickel hollow-cathode

3.4 Analysis

Samples: Sample solution and Standard solutions

Concomitantly determine the absorbances of the Samples at least three times each. Record the average of the steady readings for each of the Standard solutions and the Sample solution. Plot the absorbances of the Standard solutions and the Sample solution versus the added quantity of nickel. [Note—The Sample solution should be plotted as if it had a content of added nickel equivalent to 0 μg.]

Extrapolate the line joining the points on the graph until it meets the concentration axis. The distance between this point and the intersection of the axes represents the concentration of nickel, C, in μg/mL, in the Sample solution.

Calculate the content of nickel in the portion of Fully Hydrogenated Rapeseed Oil taken:

Result = (C/W) × V

C = concentration of nickel in the Sample solution (μg/mL)

W = weight of Fully Hydrogenated Rapeseed Oil (g)

V = volume of the Sample solution, 25 mL

Acceptance criteria: NMT 1 ppm

Limit of Erucic Acid: NMT 1.0%, as determined under Speciffic Tests, in the test Fats and Fixed Oils, Fatty Acid Composition〈401〉

4 SPECIFIC TESTS

Fats and Fixed Oils, Fatty Acid Composition 〈401〉: Fully Hydrogenated Rapeseed Oil exhibits the fatty acid composition pro

le shown in Table 1.

Table 1

^a Erucic acid.

Fats and Fixed Oils, Acid Value〈401〉: NMT 6.0

Fats and Fixed Oils, Iodine Value〈401〉: NMT 4

Fats and Fixed Oils, Peroxide Value〈401〉: NMT 2.0

Fats and Fixed Oils, Unsaponifiable Matter〈401〉: NMT 1.5%

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers. No storage requirements speciffed.