| 摘要 |
An electrospray and/or APCI mass spectrometer has an evacuated chamber 8, a sampling region 7 where the pressure is greater than in said evacuated chamber 8, a sampling orifice 5 communicating between said sampling region 7 and said evacuated chamber 8, and a mass analyzer which. receives at least some charged particles along a first axis 37 through said sampling orifice 5 from said sampling region 7 into said evacuated chamber 8. A plurality of charged-particle jet generation means 1, 38-40 each of which is supplied with a fluid to be analyzed each generate a jet aligned with a jet axis 3; 45; 46; 47, of charged particles derived from said fluid, and are disposed so that each charged-particle jet generation means 1; 38-40 has a different jet axis 3; 45; 46; 47 and so that all said jet axes 3, 45-47 intersect said first axis 37 within said sampling region 7. Jet selecting means 4 comprising a hollow member 36 is disposed so that the intersections of said jet axis 3; 45; 46; 47 and said first axis 37 are within its interior, said hollow member 36 having at least a first aperture 49 alignable with said jet axis 3; 45; 46; 47 through which at least some charged particles comprised in a said charged-particle jet may enter the interior of said hollow member 36 and travel to said first axis 37. There is also means for aligning said first aperture 49 in said hollow member 36 with each said jet axis 3; 45; 46; 47 in turn, thereby allowing in turn at least some charged particles comprised in each said jet to enter the interior of said hollow member 36 to pass through said sampling orifice 5 to said evacuated chamber 8, and subsequently to be mass analyzed by said mass analyzer.
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