DETERMINATION OF 5-FLUOROURACIL IN HUMAN PLASMA BY A SIMPLE AND SENSITIVE REVERSED-PHASE HPLC METHOD

A simple and sensitive reversed-phase HPLC method with UV detection wa s developed and validated for the quantitation of 5-fluorouracil (5-FU ) in human plasma. After acidification and salting out, 5-FU was extra cted into ethyl acetate and back-extracted into a basic buffer. The ex tract was adjusted to neutral pH before being injected onto the HPLC c olumn. 5-FU was separated from the matrix components on a YMC ODS-AQ c olumn at 40 degrees C using an aqueous mobile phase of 10 mM potassium phosphate at pH 5.5. A linear gradient of 0-25% methanol wash eluted late peaks, maintained column performance, and increased column stabil ity. The run time was 20 min. The linear range was 25-300 ng ml(-1) (r (2) > 0.999). The limit of quantitation was 25 ng ml(-1), with a signa l-to-noise ratio of 23:1. Interday precision and accuracy of quality c ontrol samples were 6.2-8.4% relative standard deviation and -0.1-+1.9 % relative error.