3. Conclusions
The adverse effects of azo dyes used for coloring food products have lead to the development of highly sensitive and selective analytical methods for their determination in various food matrices. Sample preparation involves the use of a variety of extraction techniques such as membrane filtration, liquid–liquid and solid phase extraction techniques due to the highly complex composition of food. The sample treatment is an important step and must be carefully developed in order to avoid the matrix interferences and also compatible with the type of food analyzed.