Quinoline yellow is a synthetic yellow dye primarily used in the following applications:
1. **Food Coloring**: It is used as a food additive (E104 in Europe) to provide a yellow or greenish-yellow hue in a variety of products such as candies, soft drinks, desserts, and snacks.
2. **Cosmetics**: Quinoline yellow is used in certain cosmetic products like shampoos, soaps, and lotions to impart a bright yellow color.
3. **Pharmaceuticals**: It is used to color medicines, particularly in tablets and capsules.
4. **Textile and Ink Industry**: It serves as a dye in textiles and inks to produce a vibrant yellow color.
5. **Laboratory Uses**: In some cases, it is used as a staining agent or as a marker in biochemical studies.
However, its use in food has been restricted in certain countries