| Trace basic orange (BO), manganese (Mn) and zinc (Zn) are all important hygienic detection items. BO is a kind of alkaline industry dye with arylamine groups, it is mainly employed to make textile fabric, leather and wood products dyed. Such colorant is recognized to be a carcinogen and is not permitted to use as food additives. However, it is used to dye yellow croakers and bean products in market, owing to that BO can adsorb proteins firmly under neutral or alkaline conditions. The intake of excessive BO can influence body health seriously. Mn can accumulate in central nervous system in human metabolic process, which can result in chronic poisoning. Furthermore, it may cause Parkinsonian syndrome in certain serious condition. Zn is called as bioelement. Short of zinic will affect the synthesis of DNA, RNA and proteins in hunman body, which causes growth retardation, dementia and so on. Therefore, it is of great importance to reinforce the hyginenic detection of trace BO, Mn and Zn.In the chapter 2, two novel methods for determination of trace BO have been developed based on the technology of resonance light scattering and high performance liquid chromatography (HPLC).①In the near neutral medium and in the presence of PVA, BO can react with I3- to form an ion-association complex, which results in the great enhancement of resonance Rayleigh scattering (RRS). The enhancement of RRS intensity was linear to the mass concentration of BO ranging from 7.58×10-3 to 1.20μg/mL with the detection limit of 2.36ng/mL (r=0.9997). In this work, the spectral characteristics and the optimum conditions of the reaction have been investigated;②A DiamonsilTMC18 column and two kinds of mobile phases were used in this paper. Methanol-0.1% formic acid was adopted to detect BO withλ= 454nm and methanol-20mmol/L ammonium acetate was used for the simultaneous determination of BO and tartrazine withλ= 428nm. Under the former condition, the linear range of BO was 0.02~45μg/mL with the detection limit (DL) of 0.008μg/mL (r=0.9999). Under the latter condition, BO and tartrazine were separated completely in 3 minutes with RS=2.93. The calibration curves for BO and tartrazine were in good linearity in the range of 0.5~100μg/mL and 0.5~200μg/mL with DL = 0.10,0.12μg/mL, respectively.In the chapter 3, using fluorescence resonance energy transfer (FRET) technique to set up new assays for determination of trace manganese and zinc.①In the buffer solution of NH3·H2O-NH4Cl at pH9.5, Mn2+ and PAN reacted to form complex. In dehydrated alcohol, the fluorescence intensity of Rh6G was diminished greatly due to the energy transfer from Rh6G to complex PAN-Mn2+. Under the optimum experimented conditions, the linear range was 12~600ng/mL(r=0.9998) and the detection limit was 3.55ng/mL;②An effective energy transfer could occur between Eosin Y (EY) and PAN-Mn2+ complex in the presence of emulsifying agent OP, which led to the great decrease of fluorescence intensity of EY. In this work, the spectral characteristics of tested system and the optimum conditions of energy transfer were investigated. The fluorescence quenching intensity was directly proportional to the concentration of Mn2+ in the range of 8.2~600ng/mL with the detection limit of 2.45ng/mL(r=0.9999);③The fluorescence intensity of Rh6G fell down when adding the Zn2+ into the tested system, and the fluorescence quenching value has a good linear relation with the added Zn2+ in the range of 13~600ng/mL. A new method was developed to determine Zn2+ in solution and the detection limit was 3.55ng/mL. The three fluorescence energy transfer systems all possess the advantages of simple operation, rapid analysis speed and high sensitivity. They can be applied to determine trace Mn2+and Zn2+with successful result.
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