qhum
第2楼2006/09/10
谈到质谱仪中的激光,那讨论的只能是MALDI(matrix-assisted laser desorption /ionization) mass spectrometer. If you have just a commercial instrument, you may not know exactly where the laser comes from. In the following, I will give you some ideas about the laser in the MALDI MS.
1. The most commonly used laser in MALDI now is N2 laser. wave length=337nm. less then 50 Hz. This kind of laser is very economic. It can last for about one year at least. If you feel there is no much energy in your laser, it's much easier to change the cartridge of the laser. You don't need to buy a new laser.
2. Another other type of laser in the UV range is Nd:YAG laser. wavelength=355 nm. Its frequency is much higher than N2 laser. It can goes up to 10 kHz.
3. For the laser working in IR range. It is normally CO2 laser. The wavelength is around 2 um.
You should keep in mind that for the UV and IR laser, they use different matrices.