Studies On The Methods Of Determination Of Tetracycline And 4－Qinnolones

This thesis has studyed the analytical methods of Tetracycline hydrochloride,lomefloxacin hydrochloride,norfloxacin and Peifloxacin mesylate. The methods have been applied to assay the samples and satisfactory results were obtained. It includes five parts as follows:Part 1: Review. A review of the published analytical methods for determination of Tetracycline and 4-qinnolones is given.Part 2: Determination of Tetracycline in Pharmaceutical Tablets By Differential Spectrophotmetry. An accurate, rapid and very simple differential spectrophotometric method for the assay of tetracycline has been developed. The method is based on the complexation reaction of Co(Ⅱ)with tetracycline at pH 11.5. Beer's law is obeyed in the concentration ranges 0.80～25mg/L for tetracycline, the maximum absorbance is 405nm,ε=1.33×104. The method gives recovery of 97.8～101.5%. It can be successfully applied to the assay of tetracycline drug formulations.Part 3: Extraction spectrophotometric determination of lomefloxacin. Extraction spectrophotometric method for determination of lomefloxacin is proposed, which is based on its extraction into chloroform as ion pairs with bromocresol green(BMG) at pH3.6.The ionic associate has maximum absorption at 415nm.The calibration graphs generated was liner over the range 1～15mg/L for lomefloxacin (r=0.9997).ε=2.5×104,the detection limit is 0.014mg/L, the recovery of method is 98.9～101.6%.The proposed method has been successfully applied to analysis of lomefloxacin in pharmaceutical formulations.Part 4: Flow Injection Spectrophotometry for the Determination of Peifloxacin Mesylate in Tablets. A flow spectrophotometric method for the determination of the antibiotic peifloxacin mesylate in drug formulation was developed. It based on the complexation reaction of Iron (Ⅲ) and peifloxacin mesylate in the 0.021mol/L sulfuric acid medium, which produce a colored complex absorbing at 440nm. The modified simplex method was utilized to establish the most efficient condition of the system.The optimum conditions attained were 0.021mol/L sulfuric acid,0.01124mol/L iron(111), flow rate 2.75mL/min,sample size 175μL. Beer's law is obeyed in the concentration ranges 20-200mg/L for peifloxacin mesylate, and a sampling frequency of 90 h-1 was attained. The recovery of the method is 97.9~101.2%, the detection limits was 4mg/L. The method has been satisfactorily used to the assay of peifloxacin mesylate Tablets. part 5: Determination of Norfloxacin by Flow injection 0n-line filtration-dilution indirect AAS. A simple, rapid and high selective method for the assay of norfloxacin has been developed. It based on the reaction of the tribasic complex of norfloxacin,Cu2+ and 5-sulfosalicylic acids. Beer's law is obeyed in the concentration ranges 0.1~0.8mg/ml for norfloxacin. The recovery of the method is 97.9~102.4%. The RSD is less than 1.7%. The method has been satisfactorily used to the assay of norfloxacin capsule.