Study On Sequential Injection Coupled With Chemiluminescence For The Determination Of The Content Of Inorganic Metal Elements

With the rapid development of society,the content of inorganic metal elements has been paid more and more attention in clinical medicine,food science,biological analysis,enviro-mental protection and so on.There are more than 90 elements in the composition of organi-sms,and among them only 26 kinds are recognized as the elements of life.Among the 26 elements,11 kinds are macro elements,including some metal elements such as calcium,magnesium,sodium and potassium;15 kinds are trace elements,such as iodine,manganese,vanadium.The macro elements and trace elements are both indispensable to life in the process of growth,development and reproduction,and will affect the normal activity of life,so there is a great significance on the determination of their content.As a branch of flow injection analysis(FIA),sequential injection analysis(SIA)has got rapid development on the basis of FIA.Because of its high degree of automation,less reagent consumption and good repeatability,SIA has been widely applied in many fields as a kind of solution processing and analysis method.Chemiluminescence(CL)analysis is a detection method based on the light emission produced from the chemical reactions,and when it is coupled with sequential injection,the reagents can be mixed online and the light signal can be catched in time,with the characteristic of rapid analysis,high sensitivity and reproducibility,and wide linear range.In this paper,the sequential injection coupled with chemiluminescence detection technique was proposed to determine some inorganic metal elements content in milk,serum and water samples,with satisfactory results.In the first chapter,the source and distribution of the life macro elements calcium,its biological effects and related diseases were introduced.Besides,the recent development of flow injection coupled technology for determination of calcium content was reviewed,including in combination with fluorescence spectrometry,electrochemical analysis,ultraviolet-visible absorption spectrometry,atomic absorption spectrometry,chcemiluminesc-ence and other analysis methods.In the second chapter,a novel sequential injection coupled with chemiluminescence for the determination of calcium in milk and serum was described.It was found that strong CL signal was generated when potassium permanganate was mixed with acid chrome blue K in alkaline medium,and the signal got stronger when calcium was added.The relative CL inten-sity was linearly related to the concentration of calcium.Under the optimum experimental conditions,the linear range for determination of calcium was from 6.00x10-7 to 3.00×10-5 mol/L(r=0.9987,N=7);The relative standard deviation for eleven repeated measurements for 1.00x1O-5 mol/L and 2.00×10-5 mol/L calcium chloride standard solution were 0.94%and 0.55%respectively,and the detection limit was 4.00x10-7 mol/L.The proposed method has been applied for the determination of calcium in different milk and human serum samples with satisfactory results,and the recovery ranged from 91.7%to 112.9%.The possible mechanism of CL reaction was discussed by scanning the luminescence kinetics curve,ultraviolet-visible absorption spectra and fluorescence spectra.In the third chapter,a sensitive sequential injection coupled with chemiluminescence for the determination of cadmium in water samples was developed.It was based on the enhancive effect of cadmium(II)on the chemiluminescence reaction in the luminol-Co(II)system,the increment of chemiluminescence intensity was liner with the concentration of cadmium(II).Under the optimum experimental conditions,the linear range for determination of cadmium was from 5.00x10-11 to 5.00×10-9 mol/L(r=0.9983,N=6);The relative standard deviation for eleven repeated measurements for 5.00×10-10 mol/L cadmium standard solution was 0.64%,and the detection limit was 1.40x10-11 mol/L.The proposed method has been applied for the determination of cadmium(II)in three kinds of water samples and environmental standard sample of cadmium(II)with satisfactory results,and the recovery ranged from 82.5%to 109.7%.The possible mechanism of CL reaction was also discussed.In the last chapter,the proposed sequential injection technique coupled with chemilumi-nescence for the determination of inorganic metal elements calcium and cadmium was summarized.