气相色谱-质谱法测定鱼腥草挥发油中甲基正壬酮含量

Determination of methyl nonyl ketone in volatile oil from herbs of Houttuynia cordata by GC-MS

目的:建立鱼腥草挥发油中甲基正壬酮的含量测定方法。方法:DB-5(0.25mm×30m,0.25μm)弹性石英毛细管柱,载气为高纯氦气,柱温采用程序升温,进样口温度240℃,质谱接口温度250℃,离子源温度200℃,选择离子检测,选取离子为57,58,170,198。结果:甲基正壬酮进样量在5.5～110ng,呈良好的线性关系,平均加样回收率为99.3%,RSD1.8%。结论:建立的GC-MS选择离子检测内标定量方法,具有灵敏、快速、准确的特点,可供鱼腥草挥发油中甲基正壬酮的含量测定及其质量控制。

Objective：To develop a GC-MS method for the determination of methyl nonyl ketone in the volatile oil from the herbs of Houttuynia cordata.Method：The sample was split in the 240 ℃ injection port,with 20∶1 split ratio,and separated on a DB-5（30 m×0.25 mm,0.25 μm film thickness）fused silica column with helium as the carrier gas.The temperature program was as follows：100 ℃ for 2 min,the 5 ℃·min-1 to 150 ℃,then 15 ℃·min^-1 to 200 ℃,and kept for 10 min.The MS transfer line temperature was set to 250 ℃,the MS source temperature was set to 200 ℃.The ionization mode was electron ionization（EI）and the selective ion monitor mode was used.Result：A good linear relationship was constructed over the injection amount range of 5.5-110 ng of methyl nonyl ketone.The average recovery was 98.9%,and RSD was 2.2%.Conclusion：The developed method was sensitive,accurate,and can be used for the determination of methyl nonyl ketone in the volatile oil and for the quality control of H.cordata.