Abstract:
AimTo analyze the response factors of different quinolone antibiotics detected by evaporative light-scattering detector(ELSD). MethodsThe response factors of five different quinolones (enoxacin, levofloxacin, ciprofloxacin, lomefloxacin and gatifloxacin) detected by ELSD were determined by using a YMC-Pack ODS-AM cloumn (150 mm×4.6 mm ID, 5 μm)as analytical column and 0.5% triethylamine(adjusting pH 2.5 with trifluoroacetic acid)-acetonitrile (48∶12) as mobile phase at a flow rate of 0.6 mL·min
-1, the temprature of the drift tube was set at 117 ℃,and the flow of carrier gas at 3.0 L·min
-1. Detector responses (
A) and the amount of injection of each substance (
M) were fitted to the logarithmic regression: log
A=
b log
M+log
A. ResultsThe linear regression equation obtained were: enoxacin:
Y=1.079 9X+2.761 1,
r2=0.999 6; levofloxacin:
Y=1.091 3X+2.723 5,
r2=0.999 7; ciprofloxacin:
Y=1.082 8X+2.752 3,
r2=0.999 4; lomefloxacin:
Y=1.089 1X+2.739 1,
r2=0.999 3; gatifloxacin:
Y=1.087 8X+2.739 2,
r2=0.999 5. The differences between them were negligible. ConclusionDifferent quinolones can give the same responses with ELSD detection. So, the HPLC-ELSD methods can be applied to the determination of new substances by using another substance as reference.