Department of Chemistry, Washington State University, Pullman, Washington, USA.
J Mass Spectrom. 2022 Apr;57(4):e4825. doi: 10.1002/jms.4825.
The relationships between resolution, stability, pseudopotential well depth, acceptance aperture, and transmission for sinusoidal quadrupole mass filters are examined graphically and mathematically. Simple linear or power relationships are revealed. Comparison of these quantities plotted against resolving power show that the pseudopotential well depth correlates well with the mass filter transmission. Pseudopotential well depth is directly proportional to the product of dimensionless stability well depth and the AC voltage. This relationship extends to all quadrupoles regardless of operational zone because it is rooted in stability. Ion transmission and sensitivity scale directly with the pseudopotential well depth. Resolving power and pseudopotential well depth increase when operating in higher stability zones for all types of mass filters. Unfortunately, for fixed frequency sine wave mass filters, the increased resolving power and pseudopotential well depth are accompanied by a significant reduction of the mass range and increased in fringe field effects. For these reasons, sine mass filter operation in higher stability zones has been reported but not commercially produced. In contrast, for rectangular wave mass filter operation, there is no mass range limitation in any stability zone. The fringe field does not increase because the AC voltage is constant and does not change within a single stability zone or between them. A DC voltage is also unnecessary to access any zone. The high resolution and sensitivity of rectangular wave mass filters that can be gained by operation in higher stability zones without mass limit and limited fringe field restrictions suggest a bright and expansive future for this technology.
正弦波四极滤质器的分辨率、稳定性、赝势阱深度、接收孔径和传输之间的关系通过图形和数学方法进行了检验。揭示了简单的线性或幂律关系。将这些量与分辨率作图比较表明，赝势阱深度与质量滤波器的传输率密切相关。赝势阱深度与无量纲稳定阱深度和交流电压的乘积成正比。这种关系适用于所有四极杆，无论操作区域如何，因为它源于稳定性。离子传输和灵敏度与赝势阱深度直接相关。对于所有类型的质量滤波器，在更高的稳定性区域中操作时，分辨率和赝势阱深度都会增加。不幸的是，对于固定频率正弦波质量滤波器，增加的分辨率和赝势阱深度伴随着质量范围的显著减小和边缘场效应的增加。出于这些原因，虽然已经报道了在更高稳定性区域中进行正弦质量滤波器操作，但并未商业化生产。相比之下，对于矩形波质量滤波器操作，在任何稳定性区域中都没有质量范围的限制。边缘场不会增加，因为交流电压是恒定的，并且在单个稳定性区域内或它们之间不会改变。也不需要直流电压来访问任何区域。通过在没有质量限制和边缘场限制的情况下在更高的稳定性区域中操作，可以获得矩形波质量滤波器的高分辨率和高灵敏度，这表明该技术具有光明而广阔的未来。
