Grossert J Stuart, Cook Matthew C, White Robert L
Department of Chemistry, Dalhousie University, Halifax, NS, Canada B3H 4J3.
Rapid Commun Mass Spectrom. 2006;20(10):1511-6. doi: 10.1002/rcm.2506.
In contrast to the well-described McLafferty rearrangement in odd-electron cations, relatively little has been reported on comparable rearrangements in even-electron ions, especially negative ions. This work reports a systematic study using tandem mass spectrometry (MS/MS) fragment ion spectra of carboxylate anions having a suitably acidic proton in the gamma position. The rearrangement process was studied in both ion trap and triple quadrupole mass spectrometers; characteristic enolate anions and stable neutral products were formed at low collision energies. The process has diagnostic and analytical potential in, for example, the analysis of peptides having C-terminal serine residues and of 3-hydroxy- or 3-aminocarboxylic acids in complex mixtures.
与在奇电子阳离子中已得到充分描述的麦克拉弗蒂重排不同，关于偶电子离子，特别是负离子中类似重排的报道相对较少。这项工作报道了一项系统研究，该研究使用串联质谱（MS/MS）对在γ位具有适当酸性质子的羧酸根阴离子的碎片离子光谱进行分析。在离子阱和三重四极杆质谱仪中都研究了重排过程；在低碰撞能量下形成了特征性的烯醇负离子和稳定的中性产物。该过程在例如分析具有C端丝氨酸残基的肽以及复杂混合物中的3-羟基或3-氨基羧酸方面具有诊断和分析潜力。
