Determination of mevalonic acid in human urine by liquid chromatography with precolumn derivatization and fluorescence detection

Mevalonic acid (MVA) is a useful indicator of the rate of cholesterol biosynthesis. We have established a highly sensitive and selective method for the determination of MVA in human urine by liquid chromatography (LC) with fluorescence detection. MVA in human urine was extracted with a phenylboronic acid-bonded solid-phase extraction column and converted into mevalonolactone (MVL) by treatment with cation-exchange resin. MVL was derivatized with 2-(p-aminomethylphenyl)-N,N-dimethyl-2H-benzotriazolyl-5-amine, followed by LC separation with column switching and fluorescence detection. The assay showed a linear response for human urine spiked with MVA over the concentration range 0–400 ng ml−1. The standard deviation was <15% except for 18.9% at the control level, with relative errors of −11.9 to 13.1%. The urinary excretion levels of MVA in 26 male human volunteers were from 160 to 549 μg day−1 with a mean level of 279±20 μg day−1 (mean±SE).