Removal of Ferrous using Citric Acid in Patchouli Oil Purification by Complexometry

This study is aimed to examine citric acids as a potential chelating agent to decrease colloidal impurities in patchouli oil to improve its quality. It covers colour, specific density, refractive index, acid value, iron content, oleoresin oil content, and patchouli alcohol. Complete Randomized Design with factorial design is used with two factors and repeated 3 times. Factors are (1) citric acid concentration consists of 0.25%, 0.5%, 1.0% and 1.50% (w/v), (2) stirring time of 30, 60 and 90 minutes. Further, purified oil by citric acid was compared to purified oil by Ethylene Diamine Tetra Acetate (EDTA). Findings show that the concentration of chelating agents and the time of stirring have an effect on the quality of patchouli oil. The higher the chelating concentration and the more the stirring time, the better the quality of purified patchouli oil in terms of colour, specific density, refractive index, acid value, and iron content. Findings also show that citric acid has almost the same performance as EDTA. The main components in patchouli oil (patchouli alcohol and oleoresin oil) are not affected by treatment. Purified patchouli oil by using citric acid meets Indonesian National Standard (SNI) requirements so citric acid is one of the potential chelating agents.