ESSENTIAL OILS AND THEIR CONSTITUENTS. XXV. 159 Figure 1. Thin layer chromatogram of oil of Bois de Rose Cayenne: a. Authentic b. Adulterated. Sample volume: IX. Developing solvent: Benzene-methanol (z[0:3). Chromatoplate heated for 15 minutes at after spraying

160 JOURNAL OF THE SOCIETY' OF COSMETIC CHEMISTS It was found that the chromatographic patterns observed were highly characteristic and could be used for the recognition of product authenticity and the detection of sophistications as well as the distinc- tion of products of different botanical and geographical origins. Appraisal of Producl Authenticity and Detcction of Adulteration Figure la shows the thin layer chromatogram of a genuine Cayenne rosewood oil. Many such samples were examined similarly and found to yield identical chromatograms. During the course of the studies the authors encountered, however, a commercial specimen which gave an abnormal chromatographic pattern (Fig. lb). In accordance with this observation the gas chromatograms of the two products (Fig. 2) were also found to be significantly different. A strong peak, corresponding Table IV Distinction of Spearmint Oils by Thin Layer Chromatography Ma•or Constituent Relative Rf 2]//. Jl//. Value cardiaca spicata viridis cis-Carveol Linalo61 Unknown A Carvone Unknown B cis-Carveyl Acetate 0.27 + + + 0.45 + + + 0.58 -- q- -- 1.00 + + + 1.38 + + + 1.54 -- + Table V Characteristic Spots Observed in Chromatogram of Oil of Gingergrass Relative Rf Color Characterization 1.00 1.34 1..50 1.9.5 2.26 1. O0 1.40 A. Solvent System: Benzene Violet Carvone Faint blue a,/%Unsaturated carbonyl compound, infrared absorption at 1663 cm.-• Pink, gradually turning green Limonene oxide Faint pink, gradually turning purple Unknown A Faint pink, gradually turning purple Unknown B B. Solvent Sysle•n: Benzene-methanol Faint pink trans-Limonene diol Deep red Unknown