Simplified high performance liquid chromatographic quantitation of antipyrine

Antipyrine is used as an index of hepatic drug metabolism. The authors devise a simple and rapid high performance liquid chromatography method to quantitate antipyrine in serum with small volume (50 microliters). Minimal sample preparation is needed and the assay is sensitive to concentrations of 0.2 micrograms/ml. Mobile phase consists of 35% methanol in 67 mM phosphate buffer pH 3.5 with antipyrine detected by monitoring the eluate at 225 and 254 nm. Within-run and run-to-run coefficients of variation are less than or equal to 2.8 and 4.6%, respectively. Recoveries from serum average 100.8%. It is concluded that this technique for antipyrine is simple, rapid, and well characterized.