| The atomic absorption spectrometry is a traditional analytical method.Flame atomic absorption spectrometry (FAAS), which is frequently used for thedetermination of metal ions because of relatively high sensitivity and selectivity, is lessused for indirect determination of organic species. This thesis has studied the analyticalmethod of determination of levofloxacin, gatifloxacin by flow injection on-line solidphase extraction flame atomic absorption spectrometry. The method has been applied tothe analysis of pharmaceutical samples with satisfactory results.There are two parts in this thesis: review and study reports.Part One: reviewThe application and progress of indirect flame atomic absorption spectrometry(FAAS) is reviewed, including analysis principle, application of indirect AAS inpharmaceutical analysis, application and development of FIA-AAS indirect method andprogress of AAS coupling technique.Part Two: study reports1. Flow Injection On-line Solid Phase Extraction Flame Atomic AbsorptionSpectrometry for Indirect Analysis of Levofloxacin.A novel approach for the indirect analysis of levofloxacin was developed withflame atomic absorption spectrometry (FAAS) coupled to flow injection (FI) on-linesolid-phase extraction (SPE). The method is based on the adsorbing preconcentrationand separation of levofloxacin as an ion-pair complex of levofloxacin-Fe(Ⅲ)-ClO4 on aC18 extraction column and FAAS detection of Fe(Ⅲ) in the ion-pair complex elutedsubsequently with ethanol. The effects of various experimental conditions wereinvestigated. At a 60 s adsorption time and 8.0 mL.min-1 sample consumption rate, thecalibration curve was linear over the range of 0.2-10.0μg.mL-1 with with a linear correlation of 0.9980. The detection limit was 0.08μg·mL-1. The precision (%RSD) for11 replicate measurements of 5.0μg·mL-1 levofloxacin was 1.6%. The proposedmethod was applied to the analysis of levofloxacin in pharmaceutical formulations withsatisfactory results.2. On-line ion-pair solid phase extraction flow injection flame atomic absorptionspectrometry for indirect determination of gatifloxacin.A flow injection flame atomic absorption spectrometry (FAAS) with on-lineion-pair solid phase extraction (IP SPE) was developed for indirect determination ofgatifloxacin. In a flow injection system, gatifloxacin reacted first with ferric to form a2:1 complex cation, then the cation reacted with ClO4- to form a neutral ion-paircomplex of gatifloxacin-Fe (Ⅲ)-ClO4 and adsorbed on C18 solid phase extractioncolumn, while excessive ferric was washed with H2O to waste. The ion-pair complexadsorbed was eluted with the mixture of ethanol, water and acetonitrile (48:32:20, v/v/v)and Fe (Ⅲ) in the complex was determined with FAAS. The optimization of variousexperimental conditions was investigated. When the reaction and extraction time was 60s, the calibration curve was linear in the range from 0.05 to12.50μg.mL-1 with a relativestandard deviations of 2.0% (n=11, c=5.0μg·mL-1), and the detection limit was 0.02μg.mL-1 of gatifloxacin. The analytical frequency was 24 per hour. The method wasvalidated by analysis of gatifloxacin in capsules and tablets, and the results agreed wellwith those obtained by the UV method. The recoveries obtained were 95%-106%.
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