Basic Red 18 is a cationic azo dye used for coloring textiles. The chromophore is the cation, which contains many functional groups, but most prominently the quaternary ammonium center.
Like many dyes, methods for the removal of Basic Red 18 from waste streams has received much attention.[2]
References
^Klaus Hunger; Peter Mischke; Wolfgang Rieper; et al. (2005). "Azo Dyes". Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_245. ISBN3527306730..
^B.Noroozi; G. A.Sorial; H.Bahrami; M.Arami (2008). "Adsorption of binary mixtures of cationic dyes". Dyes and Pigments. 76 (3): 784–791. doi:10.1016/j.dyepig.2007.02.003.