Truong Ngoc Bao Tran from the HCM City Technology University plans to use citronella essential oil to make a mosquito repellant cream.

Last year, Tran received second prize at Eureka 2013, an international business plan competition. However, he wants to go further with his research work, trying to distill citronella essential oil with a microwave method to make a cream for skin care to protect people from mosquitoes.

“Green chemistry is now a growing tendency in the world. People nowadays try to restrict the use of chemicals and use natural substances instead,” Tran noted.

“This helps minimize the consequences of chemicals to the environment,” he said, explaining the reason why he decided to develop the idea.

Most Vietnamese know that citronella can be used to prevent bites from mosquitoes. However, people do not know how to take full advantage of citronella’s characteristics for this purpose.

Most people kill mosquitoes with sprays available in the market made of chemicals and aromatic spices. The chemicals kill mosquitoes very quickly and effectively. However, they bring side effects.

According to Tran, the chemicals are toxic to humans, especially to children, and they are expensive for many families.

Citronella is grown in many localities in Vietnam, allowing it to be produced at a lower cost, Tran believes.

Tran, after washing citronella carefully, chops it into small pieces, then soaks it in water for one day before putting into distillation.

He uses 400 ml of water for every 300 grams of materials, including stems, roots and leaves. The steam for distillation must be no higher than 100^oC in order to avoid oil disintegration. The mixture needs to be heated with fire or steam.

After that, Tran step by step raises the temperature until the solution boils, the essential oil condenses and flows into a water tank. Being lighter than water, the essential oil floats on the water surface, which makes it very easy to extract oil.

In an experiment, Tran puts the citronella essential oil into a tank with mosquito larvae. He discovered that the mosquito larvae died after one hour. The same outcome was obtained in an experiment in a “mosquito cage”.

Scientists said Tran’s scientific research work has very important significance when proving the capability of citronella essential oil to kill mosquitoes. It has paved the way for other studies to make up biological medicine to kill mosquitoes.

According to Tran, many people fumigate their houses with citronella, or heat citronella plants to prevent mosquitoes. But they need to have specific equipment to extract essential oil with steam.

He admitted that the volume of essential oil collected remains modest, which cannot be used on a large scale. The essential oil needs to be produced on an industrial scale, he said.