LASER DESORPTION IONIZATION MASS SPECTROSCOPE

摘要

A laser desorption ionization mass spectroscope detects, through a capacitor (32), variation in the potential arising in a metal sample plate (2) upon irradiation of a laser light on a sample (3), wherein an ion amount estimation section (35) estimates the amount of ion generated from the sample (3) in accordance with the amount of potential variation. A control section (25) increases the generated ion in amount by increasing the number of times for irradiation of the laser light when the amount of ion generated for a single irradiation of the laser light is too small. Further, the control section (25) decreases the introduced ion in amount by controlling a lens voltage generator section (22) to lower the ion passage efficiency onto an ion lens (11) when the amount of generated ion is too large and an adverse influence of the space-charge effect in a quadrupole mass filter (18) may occur. Additionally, the control section (25) controls an excitation voltage generator section (23) to adjust a gain of an ion detector (19) depending on the amount of introduced ion, thereby avoiding saturation of detected output and the like. This allows the mass spectrometry to be performed with optimal sensitivity.