Study On Electrochemistry And Capillary Electrophoresis Of Some β₂ Agonists And Effective Components Of Traditional Chinese Medicine

In this thesis, we have mainly studied on three kinds of β2－agonists, such as clenbuterol, cimaterol and sabutamol, for their simultaneous determination by capillary electrophoresis with amperometric detection(CZE-AD) and their electrochemical properties. We also develop a method for simultaneous determination of honokiol and magnolol in a traditional Chinese medicine, Huo Xiang Zheng Qi Shui, by CZE-AD. In section 1, the progress of the analytical methods for β2－agonists residues and Chinese traditional medicine was reviewed.In section 2, the electrochemical behavior of clenbuterol was investigated by cyclic voltammetry, linear sweep voltammetry chronocoulometry and bulk electrolysis with coulometry on a glassy carbon electrode. A simple, quick and sensitive method for detection of clenbuterol by Osteryoung Square Wave Stripping Voltammetry was developed. The method was applied to the assay of clenbuterol in rabbit serum and urine with satisfactory results.In section 3 and section 4, the electrochemical behavior of cimaterol and sabutamol on a Nafion modified electrode was investigated. A high selective and sensitive differential pulse voltammetry method for determination of cimaterol and a simple, quick and sensitive method for detection of sabutamol by Osteryoung Square Wave Stripping Voltammetry were developed, with a low detection limit in the sub nM range. This method was applied to the assay of cimaterol and sabutamol in rabbit serum and urine with good results. The ion-exchange selectivity coefficient, the apparent diffusion coefficient and the distribution coefficient were determined based on the data from experiments of chronocoulometry, bulk electrolysis with coulometry etc. Since capillary electrophoresis with amperometric detection has great superiority for separation and determination of electrochemical active substances, this method was applied to separation and determination of clenbuterol, cimaterol and sabutamol in section 5. Under the optimum conditions, above three analytes were separated completely within 16 min. The method has been employed for the determination of clenbuterol, cimaterol and sabutamol in rabbit urine and feed by standard addition with satisfactory results.In section 6, based on the investigation of the electrochemical characteristics of honokiol and magnolol, a method for simultaneous separation and detection of honokiol and magnolol in the traditional Chinese medicine, Huo Xiang Zheng Qi Shui, by capillary electrophoresis with amperometric detection was developed. Under the optimum conditions, the analytes were separated completely within 6 min, and the good results for the real samples were obtained.