Determination of anti-virus drug, ganciclovir, in human serum by HPLC withprecolumn fluorescence derivatization using phenylglyoxal

A selective and highly sensitive liquid chromatographic method for the dete rmination of ganciclovir (anti-virus drug) in human serum was described. Af ter ganciclovir and acyclovir (internal standard; IS) were extracted with s olid-phase extraction cartridge from serum, they were converted into fluore scent derivatives by reaction with phenylglyoxal in a phosphate buffer (pH 5.8) at 20 degreesC for 30 min. The derivatives were separated by reversed- phase column with a mixture of acetonitrile-1 mM phosphate buffer (pH 6.2) (18:82, v/v), and were then detected spectrofluorometrically at 512 nm with excitation at 365 nm. Extraction recoveries were 87.0 - 91.6% for ganciclo vir and 86.8 - 92.3% for IS. The detection limit for ganciclovir spiked to serum was 5 ng ml(-1) serum (306 fmol on column) at a signal-to-noise ratio of three. The accuracy and precision of this method were 7.6% and 5.0% eve n at low concentration (20 ng ml(-1)). The within- and between-day variatio ns are lower than 7.6% and 8.1 %, respectively.