Probe-based electrospray adapter for thermospray equipped quadrupole based LC/MS systems

Claim 1

In a thermospray equipped LC/MS analyzer having an ion source body member with a first means defining a passageway therethrough, said passageway having an inlet end and an outlet end oriented at spaced locations on said body member, second means defining an inlet orifice in an internal wall of said passageway, said inlet orifice providing ion communication between the passageway and a first chamber containing the analyzer, vacuum source means connected to said outlet end of said passageway and said first chamber, said second means including a skimmer cone encircling said inlet orifice for focusing the ions entering the inlet orifice and the analyzer, third means defining an opening through the wall of the body member and opening into said passageway for providing communication between an area outside of said housing member and said passageway, said opening being generally axially aligned with the inlet orifice, and an electrospray means for spraying charged micron size droplets of a solution of molecules of interest, the improvement wherein: an elongated probe means is provided and includes an elongated and hollow second chamber opened at one end to atmosphere and closed at the other end by a first partition; fourth means defining a first hole through said first partition; a second partition in said second chamber spaced from said first partition and defining a third chamber therebetween; an elongated and hollow probe shaft connected to and extending from said first partition on a side thereof remote from said open end, a central axis of said probe shaft being coaxial with a central axis of said first hole; an elongated and hollow drift tube and first heater means for regulating the temperature of said drift tube mounted inside said probe shaft, an inlet end of said drift tube extending through said first hole in said first partition and terminating in said third chamber, an outlet end of said drift tube extending a finite distance beyond an end of said probe shaft remote from said first partition; adjustment means for selectively adjusting the spacing between said first and second partitions; fifth means defining a second hole in said second partition coaxially aligned with said first hole, the relative spacing between said first and second partitions determining a spacing between said inlet end of said drift tube and said second hole; dry gas passageway means for facilitating a supply of dry gas to said third chamber and said second hole; second heater means for controlling the temperature of said second chamber, and plug means for closing said inlet end of said passageway in said body member; whereby the outlet end of said drift tube is connected to said third means, and whereby the spray of charged droplets into said first chamber will be drawn toward said second partition and through said second hole therethrough and thence into said inlet end of said drift tube for subsequent delivery to said passageway in said body member and thence said inlet orifice to said analyzer.