Study On Sequential Injection Coupled With Chemiluminescence For The Determination Of Dopamine And Humic Acid

Sequential Injection Coupled with Chemiluminescence(SIA-CL)is an analytical method by combining the automatic technique of the Sequential Injection Analysis with the determination method of the Chemiluminescence(CL).Therefore,the advantages of SIA-CL included the above two.For one thing,it has the merits of the CL such as the high sensitivity,the wide linear range,simple instrument and apparatus and so on;for another,it has the advantages of SIA,for example,high degree of automation,low consumption and good reproducibility,etc.Combination CL with SIA not only has retained the advantages of both,but also has formed complementary advantages.As a promising determination technique,it can be extensively used to determine the trace and ultra trace samples.In the dissertation,the sequential injection method combined with chemiluminescence detecting technique was applied for the determination of dopamine in pharmaceutical preparation and human urine and humic acid in loess,satisfactory results were obtained.Dopamine,physiological and pharmacological action of dopamine,dopamine and food safety,the determination methods of dopamine,the pretreatment of dopamine in samples were introduced in the first chapter of the dissertion.In the introduction of the determination methods of dopamine,flow injection analysis(FIA)coupled with other detection methods were presented in detail.Sequential injection with chemiluminescence to detect trace amounts of dopamine in pharmaceutical preparation and human urine was described in the second chapter.The method is based on that dopamine is oxidized by potassium permanganate with formaldehyde as an enhancer.With the optimized experimental condition,the CL intensity(I)was linearly proportional to the dopamine concentration(C,mol/L)in the range of 4.00×10-6～8.00×10-5 mol/L with the regression equation I=-13.559+1.343×107C(correlation coefficient,r=0.9970).The theoretical detection limit,calculated as the concentration that gave a three times the standard deviation of the blank signal,was 2.10×10-7 mol/L.The relative standard deviation(R.S.D.)was 3.1%for 11 determinations of 1.00×10-5 mol/L dopamine.The sampling rate was 100 samples h-1.The interferences of cations in human urine were eliminated with the aid of through cation resin micro-column.The method was applied to the determination of dopamine in pharmaceutical preparation and human urine and the recoveries were 91.3%～112.3%.In the third chapter,a simple,fast sequential injection system with chemiluminescence detection for the determination of humic acid in loess was presented,based on humic acid is oxidized by Cerium(Ⅳ)in acidic medium as rhodamine 6G is illuminant.With the optimized experimental condition,the CL intensity(Ⅰ)was linearly proportional to the humic acid concentration(C,mol/L)in the range of 0.10～46.00 mg/L with the regression equation I=36.84+58.49C(correlation coefficient,r=0.9990).The theoretical detection limit,calculated as the concentration that gave a three times the standard deviation of the blank signal,was 0.06 mg/L.The relative standard deviation(R.S.D.)was 2.1%for 11 determinations of 10.00 mg/L humic acid.The sampling rate was 120 samples h-1.The method was applied to the determination of humic acid in loess and the recoveries were 89.0%～113.3%.In the last chapter,a summary for the characteristic of sequential injection coupled with chemiluminescence detection technique was described.