สารบัญ

Thai name  น้ำมันลาเวนเดอร์ (NAMMAN LAVENDER)

Category  Pharmaceutic aid.

        Lavender Oil is the volatile oil distilled with steam from the flowering tops of Lavandula angustifolia Mill. (L. officinalis Chaix) (Family Lamiaceae).

Origin of plant  Lavender Oil-yielding plant is native to Mediterranean region, particularly France, Italy, and Spain. 

Constituents  Lavender Oil contains predominantly esters such as linalyl acetate and  a-terpinyl acetate, and monoterpenes, e.g., camphene, 1,8-cineole, limonene, and linalool. 

Description  Colourless, pale yellow, or yellowish green liquid; odour aromatic, reminiscent of the flowers; taste bitter, somewhat camphor-like.

Packaging and storage  Lavender Oil shall be kept in well-filled, tightly closed containers, protected from light, and stored at a temperature not exceeding 25°.

Identification  Carry out the test as described in the “Thin-Layer Chromatography” (Appendix 3.1).
     Standard solution  Dilute 10 µL of cineole, 5 µL of linalool, and 5 µL of linalyl acetate to 1 mL with toluene.
     Test solution  Dilute 20 µL of the sample to 1 mL with toluene.
     Adsorbent  Silica gel F254 (TLC or HPTLC plate).
     Mobile phase  Ethyl acetate and toluene (5:95).
     Application  Apply 6 µL (or 2 µL) each of Standard solution and Test solution as 10-mm (or 8-mm) bands.
     Development and drying  Allow the solvent front to ascend 10 cm (or 6 cm) above the line of application.  Dry the developed plate in air.
     Detection  Spray the plate with anisaldehyde TS, heat at 100° for 5 minutes, and examine immediately in daylight.
     Results  When examined in daylight, the test solution shows a dark violet band due to linalool and possibly a pale violet-brown band due to 1,8-cineole in the lower third of the chromatogram, and a dark violet band due to linalyl acetate in the middle of the chromatogram, corresponding in colour and R_f to the bands shown by the standard solution.  A greyish or brownish band in the lower third of the chromatogram, a pink band in the middle of the chromatogram and a violet band in the upper third of the chromatogram are present.

Relative density  0.878 to 0.892 (Appendix 4.9).

Refractive index  1.455 to 1.466, at 20º (Appendix 4.7).

Optical rotation  –12.5° to –6° (Appendix 4.8).

Acid value  Not more than 1.0; use 5 g (Appendix 5.4).