| Objective A validated HPLC method was established to analyze the gatifloxacin concentration in serum and urine.Methods Acetonitrile :0.01M monopotassium phosphate:0.01M heptanesulfonate sodium salt:triethylamine(32:34:34:1,V/V) as the mobile phase .The serum sample were pretreated with 10% trichlroacetate for removing protein,SB-C8 column as the fix phase to detect serum sample, internal standard was amodiaquin.The urine sample were pretreated with 5N NaOH and 800μl methanol to dilute and deposit impurity,SB-C18 column as the fix phase to detect urine sample., internal standard was niperotidine. Results The retention time of internal standard in serum was 5.2min , while 6.6min in urine.The retention time of gatifloxacin in serum and urine was 5.7min and 8.8min respectively.The detection limit of serum and urine were 0.05μg /ml and 0.79 μg/ml respectively.The serum and urine concentration were in well linearity in the ranges of 0.0788μg /ml～7.88μg /ml and 1.97μg/ml～394μg/ml with correlation coefficients 0.9995 and 0.9999,respectively.The relative recoveries of gatifloxacin in serum were 92.11%±10.44%,100.38%±1.42%,101.63%±1.82%,and absolute recoveries were 81.7%,75.83%,68.07%, respectively. The relative recoveries of gatifloxacin in urine were 108.5±1.93%,87.63%±0.47%,99.9%±0.2%, and absolute recoveries were 90.13%,94.07%,90.41%, respectively.The within-day derivation (RSD) in serum and urine assay were less than 11.34% and 1.78%.The between-day RSD in serum and urine assay were less than 9.35% and 1.35%.Conclusions The HPLC is a precise and simple method with high sensitivity to detect gatifloxacin concentration in serum and urine, and can be used to investigate the pharmacokinetics of gatifloxacin. |
