Caraway Oil
(kar' a way oyl).
Caraway Oil is the volatile oil distilled from the dried, ripe fruit of Carum carvi L. (Fam. Apiaceae). It contains NMT 50.0% of d-carvone (C10H14O).
•  Procedure
Sample:  10 mL of Caraway Oil
Analysis:  Transfer the Sample to a cassia flask, and add 50 mL of a saturated solution of sodium sulfite that has been made neutral to 2 drops of phenolphthalein TS by means of a saturated sodium bisulfite solution. Heat the flask in boiling water, and shake it repeatedly, neutralizing the mixture from time to time by adding a few drops of the saturated sodium bisulfite solution. When no coloration appears upon the addition of a few more drops of phenolphthalein TS and heating for 15 min, cool the mixture to room temperature. When the liquids have separated more completely, add a sufficient volume of the saturated sodium bisulfite solution to raise the lower level of the oily layer to the graduated portion of the neck of the flask.
Acceptance criteria:  The volume of the residual oily liquid does not exceed 5 mL, indicating the presence of NLT 50.0% of d-carvone (C10H14O) in the portion of Oil taken.
•  Heavy Metals, Method II 231: NMT 40 µg/g
•  Solubility in 80% Alcohol: One volume dissolves in 8 volumes of 80% alcohol.
•  Specific Gravity 841: 0.900–0.910
•  Refractive Index 831: 1.484–1.488 at 20
•  Packaging and Storage: Preserve in tight, light-resistant containers.
•  Labeling: The label states the Latin binomial and, following the official name, the part of the plant source from which the article was derived.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Maged H. Sharaf, Ph.D.
Principal Scientific Liaison
(DS2010) Monographs - Dietary Supplements
USP35–NF30 Page 1728
Pharmacopeial Forum: Volume No. 27(4) Page 2791