PERFUMES

Perfumes have a pleasant smell and they stimulate receptors in the nose. People like to use perfumes to make them smell nice and giving a good impression to others in daily life. We always use them , but do you know that the perfumes that  we use are related to organic chemistry too?

Perfumes are non-toxic chemical. People who wear it does not get poison and this can prevent the wearer suffer for skin rashes. It is insoluble in water but evaporates easily. Perfumes are categorize according to their concentration of essences or aromatic oils they contain. There are four types of perfumes, which are eau de cologne, eau de toilette and eau de parfum and perfume.

Eau de cologne contain about 7% essence dissolve in alcohol of 60º or 70º. It doesn’t last long and can reapplied directly to skin.

Eau de toilette contain up to 10%aromatic essence. It evaporates and fade away quite quickly.

Eau de parfum  contain over 15% concentration of oils, sometimes reaching as high as 20%. Can be used to spray on hair or clothing.

Perfume contain 40% high concentration of essences. The average concentration of essence in a perfume is 25%, which makes it the longest lasting of all the scent categories.

Due to the high concentration of essences in perfume, wearing perfume is last longer than wearing eau de cologne or eau de toilette. Perfume are made up by the mixture of fragrant essential oils, or aroma compound , fixatives and solvents. Also, Ester are used in perfumes , it is made by reacting an alcohol with an organic acid.

Esters are chemicals with pleasant smells. It occur naturally but can be made in laboratory by condensing an alcohol with an organic acid which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group. This reaction is called as esterification.

Word Equation:

                Alcohol  +  organic acid  →  ester  +  water

Different kind of alcohol and organic acid will form different kind of names and smells of ester.

Alcohol          Organic acid           Ester made              Smell of ester

pentanol          ethanoic acid           pentyl ethanoate          pears

octanol            ethanoic acid           octyl ethanoate             bananas

pentanol          butanoic acid           pentyl butanoate          strawberries

methanol         butanoic acid           methyl butanoate         pineapples

For example:

            Methanol  +  Butanoic acid  →  Methyl Butanoate  +  Water

This video has explained how esterification reaction occurs and how different kind of smells of perfumes made:

Written by: Tanasha Azalea Suhandani, Lee Miaw Woon, Chong Hui Qian, Sathish Kumar Letchumanan