Luo Chan, Jiang Gongyu, Konenkov Nikolai V, Ding Chuanfan
Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
Eur J Mass Spectrom (Chichester). 2009;15(6):673-9. doi: 10.1255/ejms.1037.
We report the numerical investigations of quadrupole mass filters concerning stability islands created by auxiliary radio frequency (RF) voltage with high and low frequencies near q = 0.9. The islands are located along the q axis near boundary value q = 0.908 with a low a parameter. The analysis is based upon the matrix method for stability diagram calculations and ion trajectory numerical simulation. The trajectory of ion motions is generated using Runge-Kutta-Nystrom-Dormand-Prince (RK-N-DP) order integration. The ion source model with Gaussian distribution of initial positions and transverse velocities is used. In RF-only operation mode, a resolution power of about R(0.1) = 600 without peak tails is achieved with a separation time of about 50 RF cycles. Relatively high resolution power of about 2000-3000 is observed in DC+RF separation mode with a low frequency auxiliary RF signal. The boundaries of stability diagram for additional RF voltage with high frequency are strongly diffused until the separation time is increased up to n = 300 RF cycles. The strong influence of phase shifts between main drive RF voltage and small auxiliary RF voltage on transmission is also examined. In DC + RF mode, the period of transmission varies with phase shift of pi or one period of the main drive RF voltage; and in RF-only mode this period is pi/2.
我们报告了关于四极质量过滤器的数值研究，该研究涉及在q = 0.9附近通过高频和低频辅助射频（RF）电压创建的稳定岛。这些岛沿着q轴位于边界值q = 0.908附近，且a参数较低。分析基于用于稳定性图计算的矩阵方法和离子轨迹数值模拟。离子运动轨迹使用龙格 - 库塔 - 奈斯特伦德 - 多曼德 - 普林斯（RK - N - DP）阶数积分生成。使用具有初始位置和横向速度高斯分布的离子源模型。在仅RF操作模式下，在大约50个RF周期的分离时间内，实现了约R(0.1)= 600且无峰尾的分辨率。在具有低频辅助RF信号的DC + RF分离模式下，观察到约2000 - 3000的相对高分辨率。高频附加RF电压的稳定性图边界强烈扩散，直到分离时间增加到n = 300个RF周期。还研究了主驱动RF电压和小辅助RF电压之间的相移对传输的强烈影响。在DC + RF模式下，传输周期随主驱动RF电压的π相移或一个周期而变化；在仅RF模式下，该周期为π/2。
