| This paper presents a series of sensitive FI method utilizing a chemiluminescence(CL) system of cerium (IV) with rhodamine B in sulfuric acid for the determination of ascorbic acid in vegetables and for the quantification of ultramicro calf thymus DNA. and herring sperm DNA in synthetic samples. The present work aims to develop the detection methods forthese substances and to spread the use of the CL technique. This paper consists of two parts.Part One A review on CL analysis and on the development of the determination of ascorbic acid and DNA.Chapter One A review on CL analysisThis chapter introduces the basic principles and the instrumentation of CL analysis. Mainly it summarizes the common CL system and their analytical applications, and vistas the newly developing techniques and further trends of CL method.Chapter Two The development of DNA quantificationIn this chapter, the methods for DNA determination such as spectrophotometry, fluorometry, resonance light scattering methods and CL methods are reviewed, and 62 references are cited.Chapter Three The development of the determination of ascorbic acidall kinds of methods including spectrophotometry, fluorometry, electrochemical methods, kinetic methods and CL methods for the determination of ascorbic acid in recent years are reviewed, and 55 references are cited.Part Two The application of the rhodamine B-Ce(IV) CL systemIn this part, some research reports were given. The contents of ascorbic acid in vegetables and DNA (including calf thymus DNA and herring sperm DNA) in synthetic samples were determined by flow-injection(FI) methods utilizing a CL system of cerium (IV) with rhodamine B in sulfuric acid. The detailed works are as follows:Chapter One Studies on the ultra-trace determination of DNA by FI-CL assay using Ce(IV) -rhodamine B systemIn this section, two novel CL methods for the determination of ultra-trace calf thymus DNA and herring sperm DNA were presented, based on the CL reaction of rhodamine B with Ce(IV) in sulfuric acid. The proposed methods have advantages of simplicity, rapidity, reproducibility, and especially the relatively low detection limits. The possible mechanism has also been discussed respectively. 1 FI-CL assay for thermally denatured DNAA high sensitive FI-CL method for determination of calf thymus DNA and herring sperm DNA has been developed. The method based on the CL reaction of rhodamine B-cerium (IV)-thermally denatured DNAs in sulfuric acid media. The proposed procedure allows quantitation of DNAs in the concentration range of 2.6x10-5-0.26 ug ml-1 for calf thymus DNA and 5.0xl0-8-5.0xl0-5 ug ml-1 for herring sperm DNA with correlation coefficients 0.9998 and 0.9996, respectively. The detection limits (3a) are 6.5x10-6 ug ml-1 for calf thymus DNA and 4.3x10-8 ug ml" for herring sperm DNA, accordingly. The possible CL mechanism in the system is discussed as well. 2 FI-CL assay for activated DNA by imidazole-HCl buffer solutionIn this section, a new FI-CL method for determination of calf thymus DNA and herring sperm DNA in an acidic medium were developed. Imidazole-HCl buffer solution was firstly applied to activate DNA in CL methods. In 0.8 mol/L sulfuric acid media, the CL of rhodamine B-Ce (IV) system is enhanced by DNA, which activated previously by imidazole-HCl buffer solution (pH 7.0). The enhanced intensity of CL is in proportion to log DNA in the range 1.0xl0-8-0.1 ug ml"1 for herring sperm DNA and 2.0x10-6-0.2 ug ml-1 for calf thymus DNA with the detection limits of 8.3 x10-9 ug ml-1 for herring sperm DNA and 3.5x10-7ug ml-1 for calf thymus DNA, respectively. The relative standard deviation (R.S.D) for 1.0x10-4 ug ml-1 herring sperm DNA was 0.99% and for 2.0x10-3ug ml-1 calf thymus DNA was 1.1% (n=11). Using the optimized system, DNA contents in six synthetic samples has been determined with recoveries of 99.5%-109.0%.Chapter Two Flow-injection chemiluminescence determination of ascorbic acid by use of the Ce(IV) -rhodamine B systemIn this work, a highly se...
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