Detection Methods Of Synthetic Colorants In Food

In recent years,overdoses and over-range use of synthetic colorants as well as illegal addition of industrial dyes in food have occurred frequently,which poses new challenges to food safety.Therefore,it is imperative to supervise the content of synthetic colorant and industrial dyes in food.In order to lay the foundation for the development of a simple,efficient,and rapid detection method,11 kinds of synthetic colorants allowed to be added and 15 kinds of banned industrial dyes were selected as the research objects according to the relevant standards,regulations and literature in China.What’s more,the corresponding detection methods were established,and the relevant draft standards are formulated and improved in this paper,.The main results are as follows:(1)The optimization of the solid phase extraction part of the pretreatment method in the new national standard "National Food Safety Standard for the Determination of Synthetic Colorants in Food" has been improved,and the accuracy and reliability of this standard detection method have been verified.As the current national standard "National Food Safety Standard Determination of Synthetic Colorants in Foods",the types and substrates of colorants measured are less and the purification method is not conducive to batch processing.Considering that the standard of "determination of synthetic colorants in Food Safety National Standard Food" needs to be revised according to the requirements of the National Health Commission,the paper selected two matrix(candy,chocolate)for pre-treatment method.At the same time,some parameters including the solid phase extraction column,solid phase extraction eluent concentration,and filter selection were optimizing and the optimal chromatography separation condition was established finally.The results show that the recovery rate of standard samples in the two matrices is 67.9% to 114.8% with the relative standard deviation between 0.7% and7.2%,the detection limit is 0.1 mg/kg ～ 0.8 mg/kg,and the quantification limit is 0.9 mg/kg ～2.3 mg/kg.In a nutshell,this method is accurate,reliable,and could be applied as a efficient method to determine the synthetic colorant content allowed in candy and chocolate.On this basis,the standard text of "Synthetic Colorants in Food Safety National Standard Food" was formulated and improved.(2)A high performance liquid chromatographic test method for disabling industrial dyes in four matrices(candy,chocolate,ketchup,tomato sauce)was established.According to the physicochemical properties of the 15 industrial dyes,the columns,extraction solvents,ultrasonic time,flow phase and gradient elution ratio were optimized.Finally,the best pretreatment method and chromatographic conditions were established,which could effectively separate 15 kinds of industrial dyes in 27 min.In the four substrates,the recoveries of 15 industrial dyes are between 81.0% and 110.3%,the relative standard deviations are between0.3% and 7.5%,the detection limit is 0.3 mg/kg ～ 0.9 mg/kg,and the quantitative limit is 0.8mg/kg ～ 2.4 mg/kg.The results show that the method has good reproducibility,accuracy and reliability,and can be used for daily screening and detection of industrial dyes in food.According to the research results,The physicochemical analysis methods of 15 industrial dyes in food(draft)were drawn up,which provided technical support for regulating the illegal addition of prohibited industrial dyes in food.(3)The time-of-flight mass spectrometry database of 38 kinds of industrial dyes was established,which provided scientific support for rapid screening of industrial dyes in food.There are many parameters in the industrial dye mass spectrometry database including abbreviation,CAS number,molecular formula,ionization type,retention time,parent ion,secondary mass spectrum and so on.In this paper,the primary and secondary full scan screening parameters were optimized,and the samples with standard concentration of 1 ppm were screened in order to verify the practical feasibility of the database.In order to verify this mass spectrometry database,the mass spectrum data of 20 batches of samples from large supermarkets(5 batches of candy,chocolate,ketchup and tomato sauce)were analyzed and compared.The results show that 38 kinds of industrial dyes were not detected in real samples which means that the current situation of food safety supervision in China is stable and improving.