关键词: 气相色谱, 介质阻挡放电氦等离子体检测器, 绿豆, 脂肪酸甲酯

Abstract: A rapid method for the determination of the fatty acid content in mung bean was established based on gas chromatography (GC) with a dielectric barrier discharge ionization detector combined with micro sample pretreatment. The chromatographic column adopted in this method was HP-88 (100 m × 0.25 mm, 0.25 μm) (88% cyanopropyl/aryl polysiloxane stationary liquid), and the carrier gas was super pure helium (purity 99.999 9 %) with a flow rate of 1.5 mL/min. The column temperature was programmed. The inlet temperature was 250 ℃, septum purge flow rate 3 mL/min, and split ratio 1:60. The detector temperature was 280 ℃ and plasma discharge gas flow rate 40 mL/min. The sample injection volume was 1 μL. The target compounds in samples were extracted with isooctane and esterified with potassium hydroxide/ methanol before analysis. The results showed that the sensitivity for 8 fatty acids in mung bean samples ranged from 0.105 to 0.196 μg/mL, with relative standard deviations ranging from 1.04% to 1.35%. The established method required very small amounts of samples and chemical reagents, and the sample pretreatment was simple, rapid and reproducible, and thus this method could accurately measure the content of fatty acids in mung bean.

Key words: gas chromatography, dielectric barrier discharge ionization detector, mung bean, fatty acid methyl esters