Using Headspace Gas Chromatography–Mass Spectrometry to Investigate the Volatile Terpenoids Released from the Liquidambar formosana Leaf and Its Essential Oil

Abstract

Phytoncides and aromatherapy scents mainly derive from plant secondary metabolites and are now well known for their health benefits. In this study, we analyzed the chemical composition of the leaf-derived essential oil of Liquidambar formosana (Altingiaceae) using GC-MS; we also investigated the VOCs released from L. formosana leaves and the leaf essential oil at different temperatures by means of headspace gas chromatography–mass spectrometry (HS-GC-MS). Regarding the VOCs of the leaves, monoterpenes predominated the VOCs at both temperatures, mainly comprising sabinene, followed by γ-terpinene, α-terpinene, and α-pinene. The intensity of the leaf VOCs at 50 °C was nearly three times higher than that at 25 °C; the emission of monoterpenes significantly increases at higher environmental temperatures. The VOC emissions of oxygenated monoterpenes from the leaf essential oil increased at higher temperatures (50 °C), especially those of terpinen-4-ol. Our results reveal that HS-GC-MS can be used to conveniently and directly analyze the VOCs emitted from L. formosana leaves and their essential oils and to evaluate the influence of temperature on the composition of the VOCs of specimens. These VOC studies will assist in the sustainable development and utilization of L. formosana trees for forest therapy, as well as the use of their leaf essential oil for aromatherapy.