Rapid quantitative analysis of 8-iso-prostaglandin-F2α using liquid chromatography-tandem mass spectrometry and comparison with an enzyme immunoassay method

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. Because urine contains numerous F2 prostaglandin isomers, each with identical mass and similar mass spectrometric fragmentation patterns, chromatographic separation of 8-iso-PGF2α from its isomers is necessary for its quantitative analysis using MS/MS. We were able to achieve this separation using an isocratic LC method with a run time of less than 9 min, which is at least threefold 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 to be 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.