Study On The Application Of Chemiluminescence And Its Hyphenated Techniques In Analytical Chemistry

This thesis has exploited capillary electrophoresis-chemiluminescence (CE-CL) detection interface technique and separation analysis of several important pharmaceuticals using CE-CL hyphenated technique and developed a few ultrasensitive detection methods. The content of this thesis are divided into four chapters and are listed as follow:1. We classified and concluded the literatures concerned the development and application of chemiluminescence and its hyphenated techniques including flow injection chemiluminescence (FIA-CL) and CE-CL, reviewed the development progress of chemiluminescence principle, FIA-CL and CE-CL, then put forward the research aim of this thesis.2. A simple, rapid and sensitive method for the determination of benserazide was developed by flow-injection chemiluminescence based on the enhancing effect of benserazide on the chemiluminescence of luminol - potassium ferricyanide in alkaline medium. The experimental parameters, such as the sampling time and dosage of luminol, potassium ferricyanide and sodium hydroxide, were optimized by orthogonal array designs. Under the optimal conditions, the emission intensity is proportional to the concentration of benserazide in the range of 0.01-1.0μg/ml. The detection limit for benserazide (S/N=3) turned out to be 0.9 ng/ml, which was the lowest one reported, and the relative standard deviation for 11 determinations using a 0.10μg/ml benserazide containing solution was 2.4%. The method was satisfactorily applied to the determination of benserazide in spiked urine samples.3. A new type interface in capillary electrophoresis (CE) chemiluminescence (CL) apparatus has been designed, and applied for the simultaneous determination of benserazide and levodopa. The experimental results indicated that the novel interface is characteristic of simple, reliable and simplifying the CE-CL equipment. The CE-CL conditions for the simultaneous determination of benserazide and levodopa were also optimized. Under the optimal conditions, the CL intensity was linear with concentrations of levodopa in the range of 1.0 to 100.0μg/ml, and benserazide in the range of 10.0 to 1000μg/ml, respectively. The detection limits (S/N = 3) in turn were 1.85μg/ml for benserazide and 0.12μg/ml for L-dopa with relative standard deviations of less than 3%. The proposed method has been successfully applied to the determination of benserazide and levodopa in medopar tablets and spiked urine samples.4. A novel method of on-line ultrasensitive detection of nickel (II) with capillary electrophoresis post-chemiluminescence by field amplified sample injection has been developed. A new post-chemiluminescence reaction was observed when nickel (II) was mixed with the reaction mixture after the finish of chemiluminescence reaction of luminol and H₂O₂. Several parameters such as pH of buffer solution and the concentrations of running buffer, luminol and H₂O₂ were optimized. Under the optimal conditions, the detection limit for Ni²⁺ was 1.0×10^-15mol l^-1, relative standard deviations of peak area and migration time using 1.0×10^-12 mol l^-1 Ni²⁺ (n=7) were 6.23% and 2.86%, respectively. The proposed method was successfully applied for the separation of three metal ions in their mixture.