Atmospheric Pressure Ionization (API) Mass Spectrometry. Solvent-Mediated Ionization of Samples Introduced in Solution and in a Liquid Chromatograph Effluent Stream

Abstract

Atmospheric pressure ionization (API) mass spectrometry is a novel form of mass spectrometry in which ions are generated in a reaction chamber external to the low pressure region of a quadrupole mass analyzer. Samples may be introduced in solvent-free fashion (by vaporization in a stream of preheated carrier gas, or in the effluent stream from a gas chromatograph) or with solvents (by injection of solutions, or in the effluent stream from a liquid chromatograph). Solvent-mediated ionization reactions leading to positive ions were studied. A liquid chromatograph-mass spectrometer-computer (LC-MS-COM) analytical system was constructed; the entire effluent stream from the chromatograph was vaporized through the API source.