液相色谱-质谱联用银离子诱导电离分析大蒜粉剂中二烯丙基硫化物

Qualitative and Quantitative Analysis of Diallyl Sulfides in Garlic Powder with Ag(Ⅰ) Induced Ionization by Liquid Chromatography Mass Spectrometry

烯丙基硫化物由于弱极性不电离,本实验利用Ag+柱后诱导电离对大蒜粉剂中的含硫化合物进行质谱定性,并以二烯丙基三硫醚为参比,对各种二烯丙基含硫化合物进行定量测定。采用甲醇-水梯度洗脱,色谱柱为W aters Symm etry C18(3.9 mm×150 mm,5μm)柱,流动相流速为0.5 mL/m in,30 m in实现良好分离。将1 mmol/L AgNO3衍生试剂以5μL/m in流速注入柱后管路,毛细管电压3 kV,正离子电离方式质谱检测。结果表明,含硫化合物的色谱行为符合“硫数规律”(lgk′=0.4276+0.0364n,r=0.9910);利用该类化合物摩尔吸光系数与二烯丙基三硫醚相近的原理,进行大蒜粉剂中含硫化合物定量分析,比硫酸钡重量法和银量定硫法更合理。

Diallyl sulfides have no response because of their weak polarities and difficult ionization in liquid chromatography-electrospray ionization-liquid chromatography （LC-ESI-MS）. In this study, diallyl sulfides in garlic powder were identified via the introduction of Ag（Ⅰ） induced-ionization. Meanwhile, above compounds were quantified by diallyl trisulfide （DATS） as reference. A gradient program was employed and methanol-water was used as mobile phase. The chromatographic analysis was carried out on a Waters Symmetry CIS column（3.9 mm × 150 mm,Sμm） with a flow rate of 0.5 mL/min. Under above conditions, all diallyl sulfides were separated within 30 rain. The derivative reagent of 1 mmol/L AgNO3 was injected to post-column at 5 μL/min flow rate. The ESI^＋ was used to monitor ions with 3 kV capillary voltage. The results showed that the ＂Rule of sulfur groups＂ （1gk′ = 0.4276 ＋0.0364n, r =0.9910） was observed. Based on the principle of similar molar absorption coefficients for diallyl sulfides, these compounds in garlic powder were determined by comparing with DATS, which has obvious advantage over barium sulfate gravimetric and argentometric methods.