An atmospheric pressure afterglow ionization system and method of use, for mass spectrometer sample analysis systems

摘要

An system and method for use for analyzing samples in mass spectrometers using afterglow metastable species at atmospheric pressure to controllably dissociate, fragment and ionize sample is disclosed. Metastable species are created at atmospheric pressure by application of adjustable intensity and/or frequency electrical energy in one portion of a modular electric discharge chamber, then are caused to interact with sample in a distally located portion of the electric discharge chamber, termed the "afterglow" portion, to produce ionized sample molecules and ionized sample fragments etc. The system and method can be used with any source of sample but a preferred embodiment utilizes an ultrasonic nebulizer to nebulize sample solutions, such as conventional liquid chromatography system effluents, into sample solution droplets, followed by desolvation thereof to provide nebulized sample particles, prior to sample entry to the "afterglow" portion of an electric discharge chamber. Ionization of sample occures as a result of interaction with energy released by relaxing metastable species. Operation at atmospheric pressure reduces operational, contamination and maintenance problems and allows easy introduction of sample in a liquid form.