Interprofessional Journal of Health Sciences. Vol.16 No.1 , January - June 2018.

CONSTITUENTS OF ESSENTIAL OIL IN INSECT REPELLENT RECIP

Supawan Bunrathep and Piyanuch Thongphasuk

Abstract

Note is evaporation time and characteristic of individual essential oil.  The base note essential oil is the heaviest and will last longest time than that of middle note and top note, respectively.  In order to increase evaporation time of desired scent, base note oil which has fixative property could be added into blend oil. The objectives of this study were to 1) perform blend oil temp to have longer evaporation time, 2) compare the chemical constituents of blend oil and single oils, and 3) select the chemical maker suitable for quality control this insect repellent recipe.  Blending of 4 essential oils which had been previously reported their insect repellent activities i.e. kaffir lime oil (top note), citronella grass oil (top note), lemongrass oil (middle note), together with patchouli oil (base note) in various ratio were performed.  The blend oil which had the best scent and appearance with the ratio of 1:3:1:10 was further chosen for applied in insect repellents in order to increase the evaporation time of the scent and insect repellent activity.  The chemical compositions of blend oil and single oils were analyzed by GC-MS.  The result exhibited that citronellal, citral, and patchouli alcohol which shown insect repellent activities in each oils were still remain in the blend oil.  Patchouli alcohol (20.16%) and citronellal (9.60%) were also the most abundant together with a-bulnesene (12.95%) and a-guaiene (10.86%) in the blend oil. Compared with single oil, patchouli alcohol was the main compound in patchouli oil (23.13%), and citronellal was also the major compound in kaffir lime oil (70.98%), and citronella oil (30.94%).  Even though citral which was exhibited the most abundant in lemongrass oil (69.01%), but it was less than that of the single oil.  This finding was assumed that the blend oil could be able to further applying in insect repellent formulation; and patchouli alcohol and citronellal were selected to be the chemical markers for quality control.  However the evaporation time of blend oil compared with individual single oil was further studied.

Keywords: Insect repellent recipe, Kaffir lime oil, Citronella oil, Lemongrass oil

Download Full Paper.