Patent ID: 7687771
Filing Date: 2010-03-30
Classification: G01N,H01J

Abstract:
1. A mass spectrometer interface, comprising: a) at least a first ion source having an exit from which a beam of analyte ions are emitted; b) a curtain plate member and a first aperture in the curtain plate member; c) an orifice plate member having an orifice therein, said orifice plate member being spaced from said curtain plate member defining a flow passageway therebetween, the first aperture in the curtain plate member being non coaxially aligned with the orifice in the orifice plate; d) gas flow mechanism for directing a counter flow gas into said flow passageway; e) power supply for applying suitable voltages to the ion source, and the curtain plate member for electrostatic lensing of the analyte ions emitted from an ion source toward a sample entrance through the aperture in the curtain plate member; and f) wherein when analyte ions from the at least a first ion source are directed in an initial flow direction towards the first aperture located in the curtain plate member some of these analyte ions are drawn through the first aperture by an electric field between the orifice plate and the curtain plate, and wherein the analyte ions entering through the first aperture in the curtain plate towards the orifice in the orifice plate encounter a counter flow gas in the flow passageway away from the orifice in the orifice plate, and wherein a low pressure maintained in a vicinity of the sample entrance of a first vacuum stage of a mass spectrometer draws analyte ions through the orifice in the orifice plate towards the sample entrance of the mass spectrometer.