Zhang Junmei, Brodbelt Jennifer S
Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, USA.
J Mass Spectrom. 2003 May;38(5):555-72. doi: 10.1002/jms.472.
A series of chalcones were characterized by electrospray ionization tandem mass spectrometry (MS(n)). Several ionization modes were evaluated, including protonation, deprotonation and metal complexation, with metal complexation being the most efficient. Collision-activated dissociation (CAD) was used to characterize the structures, and losses commonly observed include H(2), H(2)O, CO and CO(2), in addition to methyl radicals for the methoxy-containing chalcones. CAD of the metal complexes, especially Co(II) (chalcone-H) 2,2'-bipyridine, allowed the most effective differentiation of the isomeric chalcones with several diagnostic fragment ions appearing upon activation of the metal complexes. MS(n) experiments were performed to support identification of some fragment ions and to verify the proposed fragmentation pathways. In several cases, MS(n) indicated that specific neutral losses occurred by stepwise pathways, such as the neutral loss of 44 u as CH3* and HCO*, or CH(4) and CO, in addition to CO(2).
一系列查尔酮通过电喷雾电离串联质谱法（MS(n)）进行了表征。评估了几种电离模式，包括质子化、去质子化和金属络合，其中金属络合最为有效。采用碰撞诱导解离（CAD）对结构进行表征，除了含甲氧基查尔酮会损失甲基自由基外，常见的损失包括H(2)、H(2)O、CO和CO(2)。金属络合物的CAD，特别是Co(II) (查尔酮-H) 2,2'-联吡啶，能最有效地区分异构体查尔酮，金属络合物活化后会出现几个诊断性碎片离子。进行了MS(n)实验以支持某些碎片离子的鉴定并验证所提出的碎裂途径。在几种情况下，MS(n)表明特定的中性损失通过逐步途径发生，例如除了CO(2)外，还会以CH3和HCO或CH(4)和CO的形式中性损失44 u。
