Continuous flow fast atom bombardment with packed microcolumns: A comparison of precolumn versus coaxial matrix delivery

Abstract

The effect of adding glycerol to the mobile phase on the chromatographic separation of peptides has been investigated using a continuous flow fast atom bombardment (CFFAB) interface coupled with commercial packed microcolumns (25 cm × 320 μm.i.d.). In a comparative study using a UV detector, it was found that chromatographic peak broadening progressively increased with increasing percentage of glycerol in the mobile phase. In the liquid chromatographic FAB mass spectrometric analysis, this effect is compounded by the dynamic mixing of the column effluent on the probe. Improvements of 25-155% in the overall separation efficiencies were obtained by introducing the matrix independently to the probe tip via a coaxial arrangement. Application of this coaxial CFFAB is demonstrated by the analysis of peptide mixtures and tryptic digests.

Microcolumn liquid chromatography: instrumentation, detection and applications

“…This matrix generally consists of an aqueous glycerol solution. The matrix solution can be either coaxially added to the post-column effluent [243,244] via an addition tee [245,246]. Alternatively, the glycerol matrix can be added to the mobile phase [247,248].…”

Detection of new spider toxins from a Nephilengys borbonica venom gland using on-line μ-column HPLC continuous flow (FRIT) FAB LC/MS and MS/MS

“…Packed m-column HPLC could be coupled with a mass spectrometer using FRIT-FAB interface without postcolumn splitting because of its low flow rate [Kassel et al, 1991a,b]. Pleasance and co-workers reported the effect of matrix additions to the mobile phase on the chromatographic separation and designed the post column FAB matrix addition system [Pleasance et al, 1990] that could maintain the polarity and viscosity of the mobile phase and permit the use of a UV detector before the introduction of samples into the mass spectrometer, thus avoiding the UV signals of the employed matrix. FAB mass spectra of spider toxins showed a characteristic (M1H) 1 ion, but lacked sufficiently intense fragment ions required for structure analysis.…”

Atmospheric pressure ion-sampling system for liquid chromatography/mass spectrometry analyses on a benchtop mass spectrometer

“…Although GC/MS is now taken for granted and commercially available, on-line condensed-phase separations such as liquid chroma-Although there are several viable LC/MS approaches to consider, we prefer the flexibility provided by atmospheric pressure ionization (API). In contrast, continuous-flow fast atom bombardment (CFAB) has gained popularity as an interface for LC/MS (3) as well as capillary electrophoresis/mass spectrometry (CE/MS) (4). Although particle beam LC/MS utilizes a standard electron ionization (El) or chemical ionization (Cl) source, both thermospray and CFAB require a separate ion source.…”