Single port thermospray ion source with coaxial vapor flow

An ion source comprising,

• a housing having a sample vapor port and having a vapor spray chamber in communication with said sample vapor port to receive a vapor flow via said vapor port,
• means for ionizing molecules within said vapor spray chamber, and
• ion extraction means in communication with said spray chamber for receiving ions from said vapor spray chamber,
• said housing having an exhaust path defined therein, said exhaust path having an inlet downstream of said ion extraction means and further having an outlet to said sample vapor port, said housing being sealed opposite to said vapor port.

An apparatus for providing an ion vapor to be analyzed comprising,

• means for vaporizing a liquid sample, said vaporizing means having a tubular outlet portion,
• an ion source having a port and means for seating said outlet portion of said vaporizing means to said ion source via said port, the area of said port being greater than the cross-sectional area of said tubular outlet portion, said ion source further having a spray region at a release end of said tubular outlet portion and having a vapor return path originating at said spray region opposite to said release end and extending to said port adjacent to said tubular outlet portion for flow thereabout, said ion source being sealed opposite to said port,
• an exhaust tube disposed in substantially coaxial alignment with said tubular outlet portion and coupled to said port,
• first vacuum means in fluid communication with said exhaust tube for drawing vapor from said spray chamber through said vapor return path and said port to provide a coaxial relationship of vapor flow through said tube with said outlet portion of said vaporizing means, and
• second vacuum means for drawing a minor portion of vapor from said spray region for mass analysis.