Quick Determination of Levofloxacin in Human Plasma by Solid Phase Extraction and RP-HPLC with Fluorometry

OBJECTIVE To set up a new method to quickly determine Levofloxacin in human plasma by SPE and RP-HPLC with fluorescence detection.METHODS To extract the Levofloxacin in human plasma by SPE with C18 SPE column,then to determine the quantities of the Levofloxacin by RP-HPLC.The chromatography column used was a ODS-BP column(5 μm,250 mm×4.6 mm).And the mobile phase was made up of the water solution(including L-isoleucine(1.31 g·L-1) and CuSO4(0.80 g·L-1) and methanol(80:20).The excitation and emission wavelengths were 280 nm and 504 nm.The flow rate was 0.8 mL·min-1.RESULTS The linear range of the method was 1.0 ~20 μg·mL-1,and r value was 0.9976;the detection limits was 1 ng·mL-1(S:N=3:1);and the extraction recovery and the method recovery were 89.12% and 109.47% respectively;the within-day RSD was 3.2%;the between-day RSD was1.4%.CONCLUSION The method is simple in the pretreatment of the bio-samples;it's sensitive and precise.And it can be applied to rapid determinations of Levofloxacin.