For preparing fluorinated quinolone antibiotic medicine locally used in stomatology, simultaneous determination of norfloxacin, ciprofloxacin, and enoxacin was carried out by multiphase ion chromatography with fluorescence detection. Quinolone antibiotics were separated by Dionex OmniPac PAX-500 column with an eluent of 15 mmol/L H2SO4 and 35% methanol （v/v） at a flow-rate of 1.0 ml/min and detected with fluorescence with excitation and emission wave lengths of 347 ran and 420 ran respectively. The detection limits （S/N=3） of norfloxacin, ciprofloxacin and enoxacin were 50, 105 and 80 ng/ml respectively. The relative standard deviations of retention time, peak area and peak height were less than 1.1% and good linear relationship resulted. The developed method was applied to pharmaceutical formulations and biological fluids.
ZHANG Yan-zhenZHANG Zheng-yiZHOU Yan-chunLIU LiZHU Yan
In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.
Yun Chang FanZheng Liang HuMei Lan ChenChao Shen TuYan Zhu
Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chroma-tography (IC) method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate (anticariogenic agents), sorbate (a preservative), and saccharin (an artificial sweetener) in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns, and suppressed conductivity detection. Optimized analytical conditions were further evaluated for accuracy. The relative standard deviations (RSDs) of the inter-day's retention time and peak area of all species were less than 0.938% and 8.731%, respectively, while RSDs of 5-day retention time and peak area were less than 1.265% and 8.934%, respectively. The correlation coefficients for targeted analytes ranged from 0.999 7 to 1.000 0. The spiked recoveries for the anions were 90%~102.5%. We concluded that the method can be applied for comprehensive evaluation of commercial gargles.
