title: Determination of LTE4 in human urine by liquid chromatography coupled with ionspray tandem mass spectrometry.
abstract: A sensitive and specific high-performance liquid chromatographic/ionspray tandem mass spectrometric (LC/ionspray MS/MS) method was developed and validated to quantitate leukotriene E4 (LTE4) in human urine. This method involves solid-phase extraction with Empore membrane disks to isolate LTE4 and its internal standard, LTE4-d3, from the urine stabilized with antioxidant and metal ion chelating agent. The reconstituted extracts were analyzed by LC/ionspray MS/MS in the selected reaction monitoring (SRM) mode. The assay has a lower level of quantitation (LOQ) of 50 pg ml-1 for LTE4 based on 5 ml aliquots of urine. The calibration graphs were linear from 50 pg ml-1 to 10 ng ml-1 for LTE4 extracted from urine. The inter- and intra-assay precision (RSD) and accuracy (DEV) did not exceed 11% and 8% at any level of the calibration standards and quality control (QC) samples, respectively. The recovery of LTE4 using the Empore disk solid-phase extraction technology was independent of LTE4 concentration in human urine. The overall extraction recovery for LTE4 was 72% (RSD = 2.14%).
authors.affiliation: Advanced BioAnalytical Services, Inc., Ithaca, New York, New York 14850, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: L Y
authors.initials: LY
authors.lastname: Li
authors.forename: J D
authors.initials: JD
authors.lastname: Henion
authors.forename: G J
authors.initials: GJ
authors.lastname: Krol
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002138:Calibration; D002614:Chelating Agents / Q000737:chemistry; D002853:Chromatography, Liquid; D003497:Cyclic N-Oxides / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D006801:Humans; D017999:Leukotriene E4 / Q000652:urine*; D008297:Male; D013058:Mass Spectrometry; D011786:Quality Control; D015203:Reproducibility of Results; D013113:Spin Labels
chemical_list: D000975:Antioxidants; D002614:Chelating Agents; D003497:Cyclic N-Oxides; D013113:Spin Labels; D017999:Leukotriene E4; D004492:Edetic Acid; C001803:tempol