Rapid quantitative analysis of 8-iso-prostaglandin-F(2alpha) using liquid chromatography-tandem mass spectrometry and comparison with an enzyme immunoassay method

Abstract

A rapid liquid chromatography-tandem mass spectrometry (LC-MS-MS) assay was developed for the measurement of urinary 8-iso prostaglandin F2α (8-iso-PGF2α), a biomarker of lipid peroxidation. Since urine contains numerous F2 prostaglandin isomers, each of identical mass and similar mass spectrometric fragmentation patterns, chromatographic separation of 8-iso-PGF2α from its isomers is necessary for its quantitative analysis using tandem mass spectrometry. We were able to achieve this separation using an isocratic LC method with a run time under nine minutes which is at least three-fold faster than previous methods—while maintaining sensitivity, accuracy, precision and reliability. The limits of detection and quantitation were 53 and 178 pg/mL urine, respectively. We compared our method with a commercially available affinity purification and enzyme immunoassay kit and found both assays in agreement. Despite the high sensitivity of the enzyme immunoassay method, it is more expensive and has a narrower dynamic range than LC-MS-MS. Our method was optimized for rapid measurement of 8-iso-PGF2α in urine, and it is ideally suited for clinical sample analysis.