In addition, this compound is volatile, resulting in a short repellent effect. Contributing to solve these problems, a high-performance liquid chromatography with diode array detection was developed for the simultaneous quantification of neral and geranial, two geometric isomers of citral. | VNU Journal of Science Medical and Pharmaceutical Sciences Vol. 36 No. 1 2020 20-29 Original Article Validation of a High-Performance Liquid Chromatographic Method with Diod Array Detection for the Quantification of Citral and Formulation of Insect Repellent Cream from Lemongrass Oil Nguyen Thi Thanh Binh Bui Thanh Tung Nguyen Thi Mai Nguyen Thi Hue 1 VNU School of Medicine and Pharmacy Vietnam National University Hanoi 144 Xuan Thuy Cau Giay Hanoi Vietnam Received 22 November 2019 Revised 16 January 2020 Accepted 20 March 2020 Abstract Lemongrass oil derived from some species of grasses in the family of Poaceae particularly Cymbopogon citratus posses a highly effective insect repellent potential. In Vietnam this product is widely commercially available but its quality is not strictly controlled. From a formulator s perspective lemongrass essential oil is not suitable for direct application on the skin because high concentrations of citral major chemical constituent of this oil may cause local irritation. In addition this compound is volatile resulting in a short repellent effect. Contributing to solve these problems a high-performance liquid chromatography with diode array detection was developed for the simultaneous quantification of neral and geranial two geometric isomers of citral. This method was used to examine the quality of some lemongrass oil samples in order to choose material for the preparation of insect repellent cream. Experimental research demonstrated that the stability of the lemongrass oil cream containing 6 of citral was significantly improved when using β-cyclodextrin a cyclic oligosaccharides capable of protecting substances by capturing them in conical structure. The obtained product showed insect repellent effect against banded sugar ant Camponotus consobrinus. This effect did not change after 6 months of storage in conventional conditions. Keywords Citral high performance liquid chromatography quantification insect repellent cream .
