The Toxicity Of Rhodamine B And Establishment Of Its Rapid Detection Method In Food Products

Rhodamine B is an alkaline industrial dye and can produces toxic impurities, such as phenol, aniline and ether in the synthesis process. Rhodamine B has been proved to cause cancer to animals and headaches, vomiting, limb pain and other symptoms by penetrating human skin. However, it has bright color, color stability, low price characteristics, some unscrupulous businessmen often illegally use it as a food coloring agent (pepper-based products), which seriously harms consumers health. This paper proved the hazards of Rhodamine B and established its rapid detection methods, which can provide effective technical support for detect residues of Rhodamine B in food.This thesis was divided into two parts. The first part proved the hazards of Rhodamine B through determining the effect of Rhodamine B on cell viability of normal hepatocytes cells L02 by MTT assay. The second part established rapid detection methods of Rhodamine B in food, including instrument detection and intuitive detection method, respectively.For instrument detection method, conditions of Rhodamine B were firstly determined by Ultra Performance Liquid Chromatography. Chili sauce, chili oil, hot pot seasoning, tomato sauce and Dongting Layu five samples were treated with an alkaline dye kit and their recovery rates were detected, thus obtaining preliminary range of pre-treatment conditions. Furthermore orthogonal experiment method was to screen and verify the optimum conditions. For intuitive detection method, chili oil, hot pot seasoning and tomato sauce three samples were selected to determine the minimum detecting limit by comparing shades of color between spiked samples and blank samples. Therefore, the intuitive and efficient method suitable for rapid detection of the field was established.Experimental results showed that Rhodamine B severely inhibited the proliferation of normal hepatocytes L02. So it is very important to establish rapid detection methods of Rhodamine B. For instrument detection method, the extraction conditions of food with less oil (tomato sauce) were established to obtain 1% acetic acid/acetonitrile as extraction agent 1 with 5 g of sample mass. On the basis of above, optimization conditions were obtained that the ratio of solid phase extraction column packingC18:LHB was 1:1, an extraction agent was 0.5% acetic acid/acetonitrile and the sample mass was 7 g. Under optimal conditions, we respectively added 5 μg/kg, 10 μg/kg and 20 μg/kg of three levels of Rhodamine B into food, the recovery rates were detected between 82.19%～88.09% and the relative standard deviations (RSD) were between 1.22%～1.33%.The optimum extraction conditions for samples with more oil were established, too. The optimal conditions were tested to be 1.5% acetic acid / acetonitrile as extraction solvent 1,6 g magnesium sulfate and 1.5 g sodium acetate as extraction agent 2, and 100 mg MgSO4 as dispersive solid phase extraction material. With chili oil as experimental subjects, the recovery rates were between 80.52%～87.63% and the relative standard deviations (RSD) were between 1.03%～1.9%. The detection limit of instrument detection was 0.4 μg/kg and the quantification limit was 1.3 μg/kg. For intuitive visual method, the lowest detection limit was 100 μg/kg by self-packed column.In the research, Rhodamine B is toxic, which seriously harms to human health. The rapid detection methods for Rhodamine B in food were established by instrument detection and intuitive detection methods. They are simple, rapid, reproducible, lower limit of detection and can detect Rhodamine B in food quantitatively and qualitatively.