HPLC-MS法测定食品中生物碱的研究

建立了一种高效液相色谱电喷雾质谱(HPLC-ESI-MS)法同时测定食品中六种生物碱的方法。采用ZORBAX SB-C8(2.1mm×150mm,3.5μm)色谱柱,乙腈(A)和pH5的4mmol/L乙酸铵溶液(B)为流动相,梯度洗脱使所有分析物均达到基线分离。采用ESI+一级质谱扫描模式得到甜菜碱、胆碱、苦参碱、阿托品、马钱子碱和乌头碱的定性离子,分别为m/z118.2、104.2、249.5、290.3、395.4和646.4,结合质谱保留时间检测六种生物碱。结果表明,采用1.0mg/mL混合标准溶液,准确性好,RSD<0.59%。该方法应用于检测实际样品荒漠肉苁蓉、山药、宁夏枸杞,添加回收率分别为81.7%~112.9%、80.8%~117.5%、96.9%~119.3%,说明建立的方法可以快速准确的检测实际样品中的生物碱成分。

Study on determination of alkaloids in food by high performance liquid chromatography mass spectrometry

An high-performance liquid chromatographic electrospray ionization mass spectrometry(HPLC-ESI-MS) method was developed for the identification of 6 alkaloids in food. A mixture of acetonitrile(A) and pH5 4mmol/L ammonium acetate aqueous solution(B) were used as the mobile phase for the chro-matographic separation on ZORBAX SB-C8(2.1mm×150mm,3.5μm) column in the gradient elution mode. Under positive electrospray ionization mode,the protonated molecularM+H]+ions for betaine(m/z 118.2),choline(m/z 104.2),matrine(m/z 249.5),atropine(m/z 290.3),brucine(m/z 395.4) and aconitine(m/z 646.4) and retain time were obtained as qualitative analysis. The experiment results indicated that RSD of the precision was less than 0.59% for adding 1.0mg/mL of spike standard. This method was used in the actual sample Herba Cistanche,Rhizoma Dioscoreae,Lycium bar-barum L testing and the average extraction recoveries were in the range of 81.7%~112.9%,80.8%~117.5%,96.9%~119.3%. A simple,rapid and accurate identification of 6 alkaloids was successfully achieved using the method.