Subpicogram detection system for gas phase analysis based upon atmospheric pressure ionization (API) mass spectrometry

Abstract

Finally, the validity of employing "half-intensity" integrations is tested. When full resolution of a profile is lacking but the central portion of the profile is not affected by interferences which occur on only one side of the profile, then the profile is scanned from its free side and the intensity integration is performed only for the free half of the profile, that is, up to the peak-height channel. A user option programs profiles for half-intensity integration at the time of acquisition. The results in Table V indicate excellent precision for 9Be, an isotope for which all lines were computed by half-intensity integration. Also, the effect of mixing half-intensity and full-intensity calculations has not harmed the precision for integrated intensity vs. peak-height intensity for those isotopes so indicated in Table V.

Orbitrap mass spectrometry: Instrumentation, ion motion and applications

“…Atmospheric pressure ionization (API) (Bruins, 1991;Carroll et al, 1974;Horning et al, 1973) sources such as ESI (Dole, Mack, & Hines, 1968;Fenn et al, 1989;Whitehouse et al, 1985;Yamashita & Fenn, 1984a,b) and atmospheric pressure chemical ionization (APCI) (Carroll et al, 1975;Horning et al, 1974a,b) coupled with mass spectrometers, especially high performance FIGURE 12. Schematic of an early prototype instrument that uses electrostatic acceleration lenses to inject ions produced by LD into the orbitrap.…”

Direct detection of benzene, toluene, and ethylbenzene at trace levels in ambient air by atmospheric pressure chemical ionization using a handheld mass spectrometer

“…Direct detection of benzene at sub-PEL levels was successful using APCI as shown in Figure 1b. Under APCI conditions, neutral benzene undergoes simple charge transfer with reagent ions (ionized components of air) to produce the molecular ion (m/z) [32]. The LOD for benzene was determined to be 0.2 ppb (Table 1).…”

Desorption Flame-Induced Atmospheric Pressure Chemical Ionization Mass Spectrometry for Rapid Real-World Sample Analysis

“…[4][5][6] To generate primary ions and metastable species for APCI processes, several approaches have been developed. 1,[7][8][9][10][11][12][13][14] e electric discharge-based technique is the most used APCI method, where various reactive species are generated in an electric discharging region under ambient conditions. 1,[8][9][10][11][12] In a corona discharge ionization source, a high DC voltage is applied to a stainless steel needle to induce electric discharge at the needle tip.…”