Liquid chromatography–tandem mass spectrometric quantification of the dehydration product of tetranor PGE-M, the major urinary metabolite of prostaglandin E2 in human urine

A LC–MS/MS method has been developed to analyze tetranor PGE-M, the major urinary metabolite of PGE2, that involves the acid-catalyzed dehydration of tetranor PGE-M and its deuterated (d6) analog followed by LC–MS/MS measurement of the dehydrated tetranor PGE-M product (tetranor PGA-M). We also report a method for quantification of creatinine in urine by LC–MS/MS to normalize tetranor PGE-M concentrations with that of urinary creatinine. These methods were used to study the effect of aspirin on urinary tetranor PGE-M levels in healthy male volunteers. Aspirin did not affect urinary creatinine concentrations but decreased urinary tetranor PGE-M concentrations by approximately 44%.