四极质谱计由四根平行的双曲面(或圆柱形)电极组成,对称的两组电极上施加的电压包含一个固定的直流成分 u 和一个射频成分 Vcosωt。一个射进这种四极场的正离子将在极性相反的两对电极间产生振荡,在一特定条件下,只有某种质荷比的离子能够以稳定的振荡通过四极场,而大于或小于这个质荷比的离子将碰 The quadrupole mass spectrometer consists of four parallel hyperboloid (or cylindrical) electrodes. The voltage applied to the symmetrical two sets of electrodes includes a fixed dc component u and a radio frequency component Vcosωt. A positive ion impinging on this quadrupole field will oscillate between two pairs of electrodes of opposite polarity. Under certain conditions, only ions of a certain mass-to-charge ratio will be able to pass through the quadrupole field with stable oscillation and be greater than Or ions smaller than this mass-to-charge ratio will touch