Determination of mevalonic acid in human urine as mevalonic acid lactone by gas chromatography-mass spectrometry.

Mevalonic acid in urine is converted to its lactone form by incubation overnight at acidic pH, extracted and analysed by GC-MS. The lower limit of quantitation of 7.5 ng/ml provides adequate sensitivity to measure changes in urinary excretion of MVA following administration of drugs which affect cholesterol synthesis. The assay is linear up to 300 ng/ml and has acceptable precision (<15%) and accuracy (<+/-20%) across the calibration range.