| abstract |
An improved ion source and means for collecting and focusing dispersed gas-phase ions from a remote reagent chemical ionization source (R2CIS) at atmospheric or intermediate pressure is described. The R2CIS is under electronic control and can produce positive, negative, or positive and negative reagent ions simultaneously. This remote source of reagent ions is separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the R2CIS into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming sample ionic species. The resulting sample ionic species are then introduced into a mass spectrometer, ion mobility spectrometer or other sensor capable of detecting the sample ions. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources; and improving the sensitivity of chemical detectors or probes. |