Leukotriene biosynthesis: direct chemical ionization mass spectrometry of underivatized arachidonic acid metabolites.
Gut-J; Trudel-JR; Jamieson-GC
Biomed Environ Mass Spectrom 1988 May; 15(9):509-516
The usefulness of direct chemical ionization (DCI) mass spectrometry for obtaining simultaneous information on both the molecular ion and diagnostic fragment ions of underivatized arachidonic-acid, 5- hydroperoxyeicosatetraenoic-acid, 15-hydroperoxyeicosatetraenoic- acid, leukotriene-B4 (LTB4), and of leukotriene-A4 (LTA4) free acid was described. In this technique, sample compounds were coated onto polyimide coated fused silica fiber and vaporized in the plume of the reagent gas plasma of a chemical ionization source without external heating of the probe. Both ammonia and isobutane DCI spectra were obtained for each compound. A volatile alkaline eluent system was developed that allowed reversed phase high performance liquid chromatography of LTA4 to be followed rapidly by DCI mass spectrometry. The conversion of LTA4 to LTB4 was confirmed using these techniques during incubation with human liver microsomes. Selected ion monitoring of preselected ion fragments in the spectrum increased the selectivity of this technique and improved quantification in the range of 100 nanograms to 10 picograms. The authors conclude that high performance liquid chromatography followed by DCI mass spectrometry is a useful tool for the analysis of oxygenated arachidonic-acid metabolites because the method allows a mass spectral analysis without time consuming methylation and silylation procedures, and because it is not restricted to eluent systems compatible with thermospray interfaces.
NIOSH-Publication; NIOSH-Grant; Grants-other; Analytical-methods; Chemical-analysis; Analytical-chemistry; Spectrographic-analysis; Hypersensitivity
Anesthesia Stanford University Department of Anesthesia Stanford, Calif 94305
Other Occupational Concerns; Grants-other
Biomedical and Environmental Mass Spectrometry
Stanford University, Stanford, California