A RAPID METHOD BASED ON UV SPECTROPHOTOMETRY FOR QUANTITATIVE DETERMINATION OF ALLICIN IN AQUEOUS GARLIC EXTRACTS

Abstract

Garlic (Allium sativum) is known for its medicinal and health food use. However, garlic extracts are also used in bio-pesticides. This study reports research on the optimisation of a fast and cheap method for assaying allicin, the active constituent of garlic extract, based on UV spectrophotometry. Garlic cloves were extracted using water. The allicin content of the garlic extracts was analysed after passing the extract through SPE cartridge and eluted with solvents of various polarities. The most polar solvent used was water which eluted the allicin in 4 ml, while methanol and ethanol did not. The absorbance of UV radiation at 240 nm and 254 nm wavelengths by the garlic fraction eluted with water gave a ratio of A240 nm/ A254 nm H” 1.4 – 1.5, which is typical for allicin.The garlic available in the Kenyan market was assayed for allicin using the optimised method. Some pesticides in the market containing garlic were also assayed for allicin. The results obtained compared well with documented values.