Triple quadrupole mass spectrometer

摘要

The present triple quadrupole mass spectrometer determines the relationship between a parameter, such as the mass-to-charge ratio of a precursor ion or that of a product ion, and the optimal collision-gas pressure giving the highest signal intensity in an MRM measurement, derives an approximate equation expressing that relationship, and stores the information representing the equation in an optimum collision-gas pressure calculation information storage section. When a measurement is to be performed, an analysis operator enters the mass-to-charge ratio of a precursor ion or product ion of a target compound. Based on the approximate equation read from the storage section, an optimum collision-gas pressure calculator determines the optimum collision-gas pressure for the specified precursor ion or product ion, and sets this pressure as a measurement condition for the apparatus.

主权项

1. A triple quadrupole mass spectrometer having: a front quadrupole mass filter for selecting, as a precursor ion, an ion having a specific mass-to-charge ratio from among various ions; a collision cell for dissociating the precursor ion by making this ion collide with a predetermined collision gas; a rear quadrupole mass filter for selecting an ion having a specific mass-to-charge ratio from among various product ions produced by the dissociation; and a detector for detecting the selected product ion, the triple quadrupole mass spectrometer comprising:
a) a prior information storage section in which information showing a relationship between an optimum collision-gas pressure giving a highest or nearly highest level of detection sensitivity and at least one parameter is previously stored, the one parameter selected from a group consisting of a mass-to-charge ratio of the precursor ion, a mass-to-charge ratio of the product ion, a sum of the mass-to-charge ratio of the precursor ion and the mass-to-charge ratio of the product ion, as well as a collision energy; and b) an optimum gas pressure calculator for calculating, based on the information stored in the prior information storage section, the optimum collision-gas pressure corresponding to a measurement condition when at least one of following parameters is set as the measurement condition: the mass-to-charge ratio of the precursor ion originating from a compound to be analyzed, the mass-to-charge ratio of the product ion, and the collision energy in a measurement.