Ionization method and apparatus including applying converged shock waves to a spray

摘要

A sample solution containing a sample component is sprayed onto an atmosphere at atmospheric approximately pressure while being applied with electric charge from the tip of a nozzle (1). A sample molecule is released as an ion in a process where charged minute liquid droplets collide with an atmospheric gas and are broken apart, and a solvent is vaporized from the respective liquid droplets. A reflectron (7) in the shape of a half-cut spheroid is arranged in such a manner that a second focal point (F2) is positioned in front of an ion-introducing portion (4) in the spray flow. A discharge electrode (8) is disposed in a position at a first focal point (F1) of the reflectron (7). When pulsed high voltage is applied to the discharge electrode (8), an electric discharge occurs, causing shock waves to be generated. The shock waves reflected on the reflectron (7) are converged on the second focal point (F2). Due to the converged shock waves, the vicinity of the second focal point (F2) rises to a high temperature, and a large pressure is also applied thereto. Therefore, vaporization of a solvent from the respective liquid droplets is further accelerated, allowing an ion to be easily generated. In addition, direct ionization can be expected. This makes it possible to improve ion generation efficiency.

主权项

1. An ionization method for ionizing a sample component for mass spectrometry, comprising the steps of:
spraying with a spraying unit a sample solution containing a sample component to develop a spray flow including a minute droplet; and applying converged shock waves with a shock wave generating member apart from the spraying unit for applying converged shock wave to the spray flow at a position immediately in front of an ion-introducing device in communication with a later stage, thereby accelerating vaporization of a solvent in the minute droplet so as to promote ion generation, wherein the shock wave generating member comprises a discharge source; a discharge electrode connected to the discharge source, for generating electric discharge to produce shock waves; and a reflector for reflecting and converging the shock waves produced by the discharge electrode, where the shock waves are converged at the position immediately in front of the ion-introducing device.