牡荆素的飞行时间质谱

Time-of-flight mass spectrometry of vitexin

利用台式飞行时间质谱的中分辨本领,研究了牡荆素的电子轰击质谱的裂解规律,对裂解途径进行了完全的指认.5个主要碎片峰可以作为鉴定牡荆素的特征离子.其中2个对应于失水离子:m/z414(39%)和378(6%);另外3个分别为黄酮苄基离子m/z283(基峰),甙元离子m/z270(19%)和黄酮乙炔离子m/z294(8%).此外,3个低丰度的离子,即2个互补离子m/z165和m/z118以及黄酮乙醛离子m/z312,可以作为鉴定牡荆素的佐证.

Using moderate resolution capabilities of a desk time-of-flight （TOF） instrument, the fragmentation regularity from electron impact mass spectra of vitexin was studied. A full assignment for the proposed fragmentation pathway was presented. Five main characteristic fragment peaks were observed, which could be used for identification of vitexin. Among them, two fragments at rn/z 414 （39%） and 378 （6%） correspond to the loss-water ions; the other three fragments are the flavone benzyl ion at m/z 283 （base peak）, the aglycon ion at m/z 270 （19%） and the flavone acetylene ion at m/z 294 （8%）, respectively. In addition, three ions with small abundances could be found as evidence： two mutual-complementing ions at m/z 165 and rn/z 118, and one flavone acetaldehyde ion at rn/z 312.