Thin Layer Chromatography - Uv-visible Spectrophotometry In The Detection Of Sudan Red Applications

Sudan red, an unnatural pigment, is a kind of dyes to be used in chemical industry, and belongs to azo dyes. It is named to Sudan Ⅰ~Ⅳ according to their structure. Sudan I and Sudan Ⅱ belong to monoazo compound, while Sudan Ⅲ and Sudan Ⅳ belong to bis-azo compound. Aniline and naphthalend, may be carcinogenic substance, are produced in the degradation of Sudan deys. It has a bright color and is hard to fade;it was appended in foodstuff by some illegal factories. China and the European alliance prohibit Sudan red be appended in foodstuff. The chief ways to test Sudan red are: HPLC, LC-MS and GC-MS.All the above ways need great-type apparatus and great expens. In addition, the wide varieties of foods make the experiment conditions more harshly. So, it has very important realistic significance to build a simple method for the determination of Sudan dyes and apply to practice.This thesis, isolates and identificates Sudan red using thin layer chromatography in advance, then detectes it by UV-Vis spectrophotometry. So, this thesis build a method --TLC-UV-Vis spectrophotometry to determinate Sudan Ⅰ ~Ⅳ. This thesis has five chapters. The first chapter makes a summary of Sudan red's character, structure, preparation and determination methods. The second chapter determinates Sudan I in foods using TLC-UV-Vis spectrophotometry. The third chapter simultaneously determinates Sudan I and Sudan Ⅱ using TLC-UV-Vis spectrophotometry.The fourth chapter simultaneously determinates Sudan Ⅲ and Sudan Ⅳ using TLC-UV-Vis spectrophotometry.The fivth chapter is simultaneous determination Sudan Ⅰ, Ⅱ ,Ⅲ,Ⅳ using TLC-UV-Vis spectrophotometry. This thesis chiefly researches the choice of developing agents, the pretreatment for different samples, the improvement of the determination conditiones;builds the analysis method that can determinate Sudan red Ⅰ ~Ⅳ respectively and simultaneously. This thesis tests the affection of interference factors, determinates the linear range and detection limit of the method, tests the rat of the recovery, compares the determination result with that of the national standard method and had a satisfactory result.European Community has set and publicated the standard determination method of Sudan red.China has promulgated the national standard GB/T19681-2005 《The method for the determination of Sudan dyes in foods-High performance liquid chromatography》 ,too.Presently, it becomes a focus that determination Sudan red in foods. The wide variety of foods makes the influence very serious. The characteristic of this thesis is, on the basis of thestructure and quality of Sudan red, this thesis deployes it by TLC first, in order to seperate Sudan red from the base, removes the base influence, improves the analysis accuracy;simultaneously, determinates it by UV-Vis which is easy widespreaded, the cost is low and the operate is easy. The method embodies the advantages that simply operate, higher seperation efficiency, easy to popularize eta.