Doroshenko V M, Cotter R J
Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Anal Chem. 1996 Feb 1;68(3):463-72. doi: 10.1021/ac950954l.
A pulsed valve was used for studying the effects of introducing heavy gases at different stages of operation of a quadrupole ion trap and for increasing the efficiency of collision-induced dissociation (CID) of peptide ions at low values of the Mathieu parametere qz. When amounts of heavy gases comparable to that of the helium buffer gas were introduced during the ion trapping, ion isolation, and mass spectral recording stages, the effects on performance were generally small or negative. However, injection of heavy gases during CID provided considerable improvement in fragmentation efficiency that depended upon the particular gas used, its mass and pressure, and the amplitude of the excitation voltage. Efficient peptide fragmentation could be demonstrated for values of qz as low as 0.05, which permitted trapping of low-mass product ions and (in many cases) full recovery of the amino acid sequence. In this report, examples are provided of monoisotopic tandem mass spectra of peptide ions with masses up to 1570 Da.
使用脉冲阀来研究在四极离子阱操作的不同阶段引入重气体的效果，以及在低马蒂厄参数qz值下提高肽离子碰撞诱导解离（CID）的效率。当在离子捕获、离子分离和质谱记录阶段引入与氦缓冲气体量相当的重气体时，对性能的影响通常较小或为负面。然而，在CID期间注入重气体可显著提高碎片化效率，这取决于所使用的特定气体、其质量和压力以及激发电压的幅度。对于低至0.05的qz值，可以证明有效的肽碎片化，这允许捕获低质量产物离子并（在许多情况下）完全恢复氨基酸序列。在本报告中，提供了质量高达1570 Da的肽离子的单同位素串联质谱示例。
