Satoh Takaya, Sato Takafumi, Tamura Jun
JEOL Ltd., Tokyo, Japan.
J Am Soc Mass Spectrom. 2007 Jul;18(7):1318-23. doi: 10.1016/j.jasms.2007.04.010. Epub 2007 Apr 24.
A novel MALDI-TOF mass spectrometer that utilizes a spiral ion trajectory was developed. In this mass spectrometer, the ions sequentially passed through four toroidal electrostatic sectors and revolved along a figure-eight-shaped orbit on a particular projection plane. Each toroidal electrostatic sector had eight stories, and during multiple revolutions, the ion trajectory shifted perpendicular to the projection plane in every cycle, thereby generating a spiral trajectory. The flight path length of one cycle was 2.1 m; therefore, when the ions completed eight cycles, the total flight path length was 17 m. By adopting an ion optical system that had a flight path length five times longer than that in the commonly used reflectron ion optical system, the mass dependence on the mass resolving power was reduced, while improving the mass accuracy of the mass measurements. The basic performance of the system was tested by using standard peptides or the tryptic digest of bovine serum albumin. A mass resolving power of 80,000 (full width at half maximum) was achieved at m/z = 2564 (ACTH18-39). An improved mass accuracy less than 2 ppm was realized over a wide m/z range of 500 to 3000 by correction using one or two internal standard substances.
开发了一种利用螺旋离子轨迹的新型基质辅助激光解吸电离飞行时间质谱仪。在该质谱仪中，离子依次穿过四个环形静电扇区，并在特定投影平面上沿八字形轨道旋转。每个环形静电扇区有八层，在多次旋转过程中，离子轨迹在每个周期垂直于投影平面移动，从而产生螺旋轨迹。一个周期的飞行路径长度为2.1米；因此，当离子完成八个周期时，总飞行路径长度为17米。通过采用飞行路径长度比常用反射式离子光学系统长五倍的离子光学系统，减少了质量对质量分辨率的依赖性，同时提高了质量测量的质量精度。使用标准肽或牛血清白蛋白的胰蛋白酶消化物对系统的基本性能进行了测试。在m/z = 2564（促肾上腺皮质激素18 - 39）时，实现了80,000（半高宽）的质量分辨率。通过使用一种或两种内标物质进行校正，在500至3000的宽m/z范围内实现了小于2 ppm的改进质量精度。
