Isolation of Thymus herba-barona volatiles by supercritical fluid extraction

A volatile concentrate of Thymus herba-barona was isolated by supercritical CO2 extraction with a fractional separation technique. GC/MS analysis of t he various fractions obtained at different extraction times and fractionati on conditions allowed the identification of the best operating conditions t o isolate the volatile extract. A good extraction performance was obtained operating at 90 bar and 50 degreesC for 300 min. The optimum fractionation was achieved by operating at 90 bar and -10 degreesC in the first separator and at 15 bar and 15 degreesC in the second one. The influence of extracti on pressure and of extraction time on the extract composition were also eva luated. A comparison between a hydrodistilled oil of Thymus herba-barona an d the supercritical extract is also given.