Patent ID: 7755036
Filing Date: 2010-07-13
Classification: H01J

Abstract:
1. A tandem time-of-flight mass spectrometer comprising: an ion source for ionizing a sample; acceleration means for accelerating the created ions in a pulsed manner; a first time-of-flight mass spectrometer (TOF-MS) of a spiral trajectory type composed of plural electric sectors, the first TOF-MS causing the accelerated ions to travel spirally; an ion gate placed within the first TOF-MS and selecting only ions having certain mass-to-charge ratios; a collision cell disposed downstream of the ion gate and filled with a gas to fragment the selected ions; a second time-of-flight mass spectrometer (TOF-MS) of a reflectron type, the second TOF-MS being disposed downstream of the collision cell, the second TOF-MS analyzing masses of the fragmented ions; and a detector for detecting ions passed through the second TOF-MS, wherein the first TOF-MS satisfies spatial focusing conditions for a direction of flight and for a plane orthogonal to the direction of flight whenever the ions make a turn in the spiral trajectory; and wherein the ion gate is placed in the spiral trajectory of the first TOF-MS and the ions selected by said ion gate pass the electric sectors disposed downstream of the ion gate and enter said collision cell.