Chemical composition of essential oils from Homalomena occulta rhizomes collected in Gia Lai/Vietnam

The essential oil samples were analyzed using the gas chromatography/mass spectrometry (GC/MS) method to determine the chemical components. The identification of the constituents in the essential oil was performed using an Agilent 8890 GC system, coupled with an Agilent 5977B mass selective detector equipped with an Agilent 19091S-433UI HP-5MS UI GC capillary column (30 m x 0.25 mm x 0.25 µm). Helium was used as the carrier gas at a constant pressure of 8.8085 psi. The injector and detector temperatures were set at 250 oC. The essential oil samples were diluted with dichloromethane solvent at a ratio of 0.1 mg/mL. The injected sample volume was 1 μL with a split ratio of 15:1. The temperature program was set with an initial temperature of 60 oC, increasing at a rate of 3 oC/min to 240 oC. The ionization process was performed at 70 eV.本研究采用气相色谱-质谱联用法（gas chromatography/mass spectrometry，GC/MS）对精油样品进行分析，以测定其化学成分。精油成分的鉴定依托安捷伦8890气相色谱系统开展，该系统联用安捷伦5977B质谱选择检测器，并配备安捷伦19091S-433UI HP-5MS UI气相色谱毛细管柱（规格为30 m × 0.25 mm × 0.25 µm）。实验以氦气作为载气，载气恒压设置为8.8085 psi。进样口与检测器温度均设定为250 ℃。将精油样品以0.1 mg/mL的浓度用二氯甲烷溶剂稀释，进样体积为1 μL，分流比为15:1。程序升温参数设置如下：初始温度为60 ℃，以3 ℃/min的升温速率升至240 ℃，电离过程采用70 eV的电离能量。