Fluorescence Approaches For Rapid Determination Of Benzimidazole Fungicides In Food

Red wine has been one of the most popularly consumed drinks in the world. However, pesticides are commonly used to treat pests and diseases of grapes in vineyard, which may cause pesticide residues in grapes and thus may induce the residues in wine through the wine-making process. As a result, pesticide residue is quite a potential health threat to people through wine consumption. The main methods used for analysis of benzimidazole fungicides are based on chromatography methods, which often consume large volumes of toxic organic solvent in the pre-treatment process and are extremely time-costing and labor-consuming. These disadvantages restrict its application in the rapid determination of benzimidazole fungicides in wine samples. Therefore, it is of great significance to propose a rapid and sensitive method for evaluating and screening benzimidazole fungicides in wine, especially thiabendazole, one of the most used benzimidazole fungicides. Spectrofluorometry is particularly suitable for analysis of benzimidazole fungicide due to its native fluorescence. Based on its obvious synergetic effect between synchronous fluorescence method and derivative technique or chemometrics methods, a rapid, simple, sensitive fluorescent method has been proposed for analysis of benzimidazole fungicides in red wine samples. The dissertation is composed of following parts.In the first chapter, the literature was summarized. The development of analytical technologies for pesticides residue was described. The current situation of analytical research for analysis of benzimidazole fungicides was summarized, including sample pre-treatment and analytical methods. The present situation of analytical study for analysis of benzimidazole fungicides residue in grape and wine was also described in details. Then, the theoretical foundation of synchronous fluorescence method and its analytical application, the incorporation between synchronous fluorescence method and derivative technique and its application in analytical chemistry were elaborated. The progress and trait of the incorporation between fluorescence method and chemometrics was introduced in details. Finally, the plans for the dissertation were put forward.In the second chapter, based on the obvious synergistic effect between synchronous fluorescence method and derivative technique, including simplification of spectra, reduction of light scatter interference and the improvement of selectivity and sensitivity, a rapid, simple, sensitive second-order derivative constant-wavelength synchronous fluorescence method for analysis of thiabendazole in wine was proposed. The simple sample treatment was achieved by using ultrasonic extraction method and microwave assisted extraction method respectively, which could greatly simplify the sample pretreatment process and shorten the total analysis time without resorting to complicated purification and pre-separation processes.In the three chapter, two fluorimetric methods were proposed for the simultaneous and rapid analysis of thiabendazole and fuberidazole in red wine samples, which were second-order derivative constant-energy synchronous fluorescence spectroscope coupled with partial least square regression and three-dimensional fluorescence spectrometry combined with trilinear decomposition algorithm such as alternating trilinear decomposition algorithm (ATLD) and parallel factor analysis algorithm (PARAFAC). The incorporation of fluorescence method and chemometrics method could effectively solve the spectral overlapping problem and achieve the simultaneously quantitative analysis of thiabendazole and fuberidazole. The tedious pre-treatment process was avoided by using "mathematical separation" instead of "physical or chemical separation".