Fractionating of green mandarin (Citrus deliciosa Tenore) essential oil by vacuum fractional distillation

• Mandarin essential oil was distilled in a fractionating column under vacuum.
• The distillation patterns were evaluated for the stages and the top of the column.
• Hydrocarbon terpenes were distilled; other chemical functions remained in the bottom.
• There was no evidence of thermal degradation of the products of the separation.
• Some trace compounds increased their mass fraction more than ten times in the bottom.

This work aims to evaluate the technical viability of vacuum fractional distillation to separate the components of green mandarin (Citrus deliciosa Tenore) essential oil. Thermal degradation was also analyzed. The obtained results demonstrate that vacuum fractional distillation is capable to separate the hydrocarbon terpenes, which were removed from the top/stages of the column, from the terpenes with other chemical functions, which remained in the bottom. Some trace compounds, such as methyl-N-methyl anthranilate (mass fraction of 0,006 in the raw oil) and alpha sinensal (mass fraction of 0,004 in the raw oil), had their concentrations increased more than ten times after the separation, to mass fraction of 0,153 and 0,109, respectively. The mass fraction of the major compound of the essential oil, d-limonene, was reduced from 0,707 in the raw oil, to 0,218 in the bottom. There was no evidence of thermal degradation in the products of the separation.