Juniper Tar
(joo' ni per tar).
» Juniper Tar is the empyreumatic volatile oil obtained from the woody portions of Juniperus oxycedrus Linné (Fam. Pinaceae).
Packaging and storage— Preserve in tight, light-resistant containers, and avoid exposure to excessive heat.
Identification— Shake 1 volume with 20 volumes of warm water, filter, and use the filtrate for the following tests.
A: To 5 mL of the cold filtrate add a few drops of silver-ammonium nitrate TS: a black color is produced.
B: To 5 mL of the filtrate add a few drops of alkaline cupric tartrate TS, and heat the solution to boiling: a red precipitate is formed.
Specific gravity 841: between 0.950 and 1.055.
Reaction— The filtrate prepared for the Identification tests is acid to litmus.
Rosin or rosin oils— Triturate 1 mL of it with 15 mL of solvent hexane, filter the solution, add an equal volume of cupric acetate solution (1 in 100), shake vigorously, and allow the liquids to separate. Decant the solvent hexane layer into a test tube, and add an equal volume of ether: the liquid does not become dark green or blackish.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
(EXC2010) Monographs - Excipients
USP35–NF30 Page 3615