Doroshenko V M, Cotter R J
Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Rapid Commun Mass Spectrom. 1996;10(15):1921-6. doi: 10.1002/rcm.1290101502.
Experiments on the influence of locking the AC and RF frequency phases on the mass resolution and line position in the mass spectra from a quadrupole ion trap mass spectrometer were carried out at low ejection values of beta z to investigate the possibility of using this effect for high mass analysis. At a typical mass scan rate of 1000 u/s the improvement for the mass resolution in these experiments did not exceed 10-20% at beta z = 0.25 compared with 200-250% at beta z = 0.5. However, without phase locking, the mass resolution at beta z = 0.25 was about two times higher than that at beta z = 0.5. Thus, the absolute values for the mass resolution observed without phase-locked AC and RF frequencies at beta z = 0.25 were about the same as at beta z = 0.5 with phase locking. This observation was explained by a significant negative contribution to the mass resolution of the ion microoscillations along the trajectory at the fundamental RF frequency which is different for the cases of beta z = 0.25 and beta z = 0.5.
在βz的低喷射值下，进行了关于锁定交流（AC）和射频（RF）频率相位对四极杆离子阱质谱仪质谱图中质量分辨率和谱线位置影响的实验，以研究利用这种效应进行高质量分析的可能性。在典型的1000 u/s质量扫描速率下，与βz = 0.5时提高200 - 250%相比，在这些实验中，βz = 0.25时质量分辨率的提高不超过10 - 20%。然而，在没有相位锁定的情况下，βz = 0.25时的质量分辨率比βz = 0.5时高约两倍。因此，在βz = 0.25时未锁定AC和RF频率所观察到的质量分辨率绝对值，与βz = 0.5时锁定相位的情况大致相同。这一观察结果的解释是，对于βz = 0.25和βz = 0.5的情况，沿轨迹以基频RF频率的离子微振荡对质量分辨率有显著的负贡献，且这种贡献有所不同。
