Quinoline Yellow WS
Quinoline yellow, Quinoline Yellow WS, C.I. 47005, or Food Yellow 13, is a yellow food dye with a maximum absorption wavelength of 416 nm.[2]p. 119 Chemically it is a mixture of disulfonates (principally), monosulfonates and trisulfonates of 2-(2-quinolyl) indan-1,3-dione.
The color Quinoline Yellow SS (Spirit Soluble), which lacks the sulfonate groups, is a related form that is insoluble in water.