Capillary Liquid Chromatography-mass Spectrometry Research Articles

Capillary liquid chromatography-mass spectrometry and micellar electrokinetic chromatography as complementary techniques in environmental analysis

Applications of capillary electrophoresis (CE) and capillary liquid chromatography (LC) to environmental analysis have been limited. In this work we present applications of micellar electrokinetic chromatography (MEKC) to the analysis of environmental matrices for synthetic dyes. Separations obtained by capillary LC are compared with those obtained under MEKC for seven selected dyes. Both techniques are capable of resolving the subject compounds at high efficiency. Recovery data for spiked water and soil matrices were obtained for four dyes using solid-phase extraction cartridges and disks with determination by MEKC-UV detection. Both pH adjustment via acid and ion-pairing via a cationic surfactant were investigated for isolating dyes. Capillary LC detection was by continuous-flow liquid secondary ion mass spectrometry (CF-LSI-MS) whereas MEKC used UV detection (214 nm). Application of peak-profiling at high mass resolution is illustrated with the capillary LC-MS technique. Interfacing capillary LC under CF-LSI-MS using the coaxial arrangement is easier than interfacing CE with this arrangement. MEKC provides a powerful screening and determinative technique, while capillary LC-MS provides a confirmatory tool.

Nanoscale separations: Capillary liquid chromatography-mass spectrometry and capillary zone electrophoresis-mass spectrometry for the determination of peptides and proteins

Nanoscale separation techniques, such as packed capillary liquid chromatography and capillary zone electrophoresis in which the column effluent flow-rates are in the nanoliter per minute range rather than microliter per minute range, have been successfully interfaced with continuous-flow fast atom bombardment and electrospray ionization. Applications of these techniques to the separation and determination of peptide mixtures, protein digests and protein mixtures are presented.

New interfacing techniques for capillary high-performance liquid chromatography-mass spectrometry

New interfacing techniques for direct coupling of liquid chromatography and fast atom bombardment mass spectrometry have recently been developed. The state of the art of capillary high-performance liquid chromatography-fast atom bombardment mass spectrometry and its application are discussed.

Packed capillary liquid chromatography-mass spectrometry using both direct-coupling and moving-belt interfaces

Packed fused-silica columns of 0.25-mm I.D. have been interfaced to a quadrupole mass spectrometer by direct coupling and to a magnetic mass spectrometer with a moving-belt interface. Electron impact (EI) and chemical ionization (CI) spectra were obtained by both techniques. Using the direct-coupling interface, we have successfully analyzed and obtained molecular ions for a number of compounds that are too thermally labile for analysis by gas chromatography-mass spectrometry. However, extremely thermally labile compounds, such as sulfonylureas, did not give MH+ ions in their CI spectra due to thermal degradation in the capillary interface line. With the moving-belt interface, MH+ ions were obtained for sulfonylureas in the CI mode. Better quality chromatograms and spectra, and better EI sensitivity were obtained with the moving-belt interface than by direct coupling.