With the successful extraction of citronella essential oil to kill mosquitoes, the student group in Secondary School of Di Che, Di Che commune (Tien Lu district) including Vu Minh Chau, Vu Long Hai and Le Hong Son (students of class 9A) under the guidance of teacher Bui Thi Thanh Nga (Biology teacher) won the second prize (the highest prize) in the first Hung Yen Youth and Children Creative Contest in 2019.
 

Starting from the desire to take advantage of locally available materials of citronella to produce cheap and safe mosquito-repellent products for people, the students came up with ideas and conducted research:  "Essential mosquito repellent extract safe for human health from citronella”.

The group consulted books, newspapers, practical ways to distill alcohol and selected available household tools to design citronella distillation equipment.  After collecting, citronella will be cleaned and put in a pot with water to distill.  After distillation, the condensation of the essential oil is flowing into a collection vessel filled with water, using a pear-shaped hopper to separate the essential oil because the oil will float on top.

Thus, to extract citronella essential oil at home, the student only invest in buying tools one time about VND 200,000 (including  copper wire, fuel) ...  

Citronella oil obtained by this distillation method is pale yellow, spicy, pleasant aroma, capable of killing mosquitoes up to 70%, maybe a few drops to kill mosquito larvae (larvae of mosquitoes). To know the proportion of citral, a precious ingredient in citronella oil, which has a bactericidal and anti-inflammatory effect, the students sent their citronella oil samples to the Center for Science and Environment for test and its result that the product contains 70% citral.  

This distillation method has advantages:  easy to carry out, it can take advantage of medicinal herbs such as citronella and other tools available in the family to create effective mosquito-repellent product from nature so it is safe, low cost, suitable for the majority of rural families.  

Vu Minh Chau, head of the research group, said:  "We are all members of the good student team of Math and Physics at the school and have the same ideas and passion for scientific research, so we gathered in a group to support each other to implement the project "Essential mosquito repellent extract safe for human health from citronella".  Taking advantage of free time and weekends, we discussed and step by step researched and manufactured products. The difficulty that we encountered was that some equipment was not available, so we had to built, tested many times and costly.  The contest give us the opportunity to apply what we have learned in practice, we can exchange and learn with friends who have the same passion for science research in the province ".

By Huong Giang