Development of a Gas Chromatography Method for the Analysis of Copaiba Oil.

A rapid, simple, precise and economic method for the quantification of main compounds of copaiba resin and essential oils (Copaifera langsdorffii Desf.) by gas chromatography (GC) has been developed and validated. Copaiba essential oil was extracted by hydrodistillation from the copaiba resin. Resin derivatization allowed the identification of diterpenes compounds. A gas chromatography-mass spectroscopy (GC/MS) method was developed to identify compounds composing the copaiba resin and essential oil. Then the GC/MS method was transposed to be used with a flame ionization detector (FID) and validated as a quantitative method. A good correlation between GC/MS and GC/FID was obtained favoring method transposition. The method showed satisfactory sensitivity, specificity, linearity, precision, accuracy, limit of detection and limit of quantitation for beta-caryophyllene, alpha-humulene and caryophyllene oxide analyses in copaiba resin and essential oils. The main compounds identified in copaiba essential oil were beta-bisabolene (23.6%), beta-caryophyllene (21.7%) and alpha-bergamotene (20.5%). Copalic acid methyl ester (15.6%), beta-bisabolene (12.3%), beta-caryophyllene (7.9%), alpha-bergamotene (7.1%) and labd-8(20)-ene-15,18-dioic acid methyl ester (6.7%) were diterpenes identified from the derivatized copaiba resin. The proposed method is suitable for a reliable separation, identification and quantification of compounds present in copaiba resin and essential oil. It could be proposed as an analytical method for the analysis of copaiba oil fraction in raw and essential oil parent extracts and after they have been incorporate in pharmaceutical formulations.