顶空固相微萃取-气相色谱-质谱法测定苦杏仁中苦杏仁苷含量
GC-MS Determination of Amygdalins in Bitter Almond with Sample Treatment by Head-space Solid Phase Micro-extraction
-
摘要: 采用顶空固相微萃取-气相色谱-质谱法对苦杏仁中苦杏仁苷进行了测定。0.1 g苦杏仁样品及4 mol·L-1硫酸4 mL置于25 mL顶空瓶中,于沸水浴水解15 min。PDMS/DVB萃取头顶空萃取20 min,萃取头于气相色谱进样口解析1 min。采用HP-5MS色谱柱在程序升温条件下进行分离。用氦气为载气,流量为1.0 mL·min-1,质谱分析中采用电子轰击电离源(230 ℃,70 eV),并在40~600 amu质量数范围内进行全扫描。结果表明:方法在100 μg·g-1以内呈线性。采用此法对市售苦杏仁中苦杏仁苷含量测定结果为60.43 μg·g-1,与分光光度法结果相符。样品5次测定结果相对标准偏差为1.8%;60 μg·g-1及20 μg·g-1两个水平添加回收率均在90%以上。Abstract: The sample of bitter almond (0.1 g) was hydrolyzed with 4 mol·L-1 H2SO4 in a 25 mL head-space bottle heated in a boiling-water bath for 15 min, and then extracted by SPME with the PDMS/DVB extractor for 20 min. The extractor was desorbed for 1 min at the inlet of the gas chromatograph, and separation of amygdalin was carried out on the HP-5MS chromatographic column with programmed temperature elevation. Helium with flow-rate of 1.0 mL·min-1 was used as carrier gas. Electron bombardment ionization (230 ℃, 70 eV) and whole scanning in the mass range of 40-600 amu were adopted in MS analysis. Linearity was obtained in the range within 100 μg·g-1. A sample of bitter almond was analyzed by this method, value of amygdalin content of 60.43 μg·g-1 was found, which is in consistency with the value determined by spectrophotometry. Value of RSD (n=5) found by analyzing the same sample was 1.8%. Values of recovery over 90% were obtained in the recovery tests at 2 concentration levels of 60 μg·g-1 and 20 μg·g-1.