Determination of LTE4 in human urine by liquid chromatography coupled with ionspray tandem mass spectrometry.
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%).
Wu
Y
Y
Advanced BioAnalytical Services, Inc., Ithaca, New York, New York 14850, USA.
Li
L Y
LY
Henion
J D
JD
Krol
G J
GJ
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
D000975:Antioxidants; D002614:Chelating Agents; D003497:Cyclic N-Oxides; D013113:Spin Labels; D017999:Leukotriene E4; D004492:Edetic Acid; C001803:tempol