Spectrophotometry for Colourant

I have been looking for a paper that by using spectrophotometry method, we can determine rate of reaction of colourant. I could not find any paper. I was wondering if any body could help me.




I'm not sure I have answer to your question maybe, if you consider natural colorant too, these are the articles that go more close to what you want:


[Prediction of phenolic compounds in red wine fermentations by visible and near infrared spectroscopy](http://www.sciencedirect.com/science/article/pii/S0003267003011541?np=y)


[Spectroscopic, stability and radical-scavenging properties of a novel pigment from gardenia](http://www.sciencedirect.com/science/article/pii/S0308814607010278)


Try to have a look a these too:


[Mimani, T., and Samrat Ghosh. "Combustion synthesis of cobalt pigments: Blue and pink." Current Science 78.7 (2000): 892-896.](http://eprints.iisc.ernet.in/1722/1/Combustion.pdf)


[Bernardi, M. I. B., et al. "Comparison of blue pigments prepared by two different methods." Journal of the European Ceramic Society 22.16 (2002): 2911-2919.](http://thaiceramicsociety.com/download/Comparison_of_blue_pigment_in_2_method.pdf)


[Visinescu, Diana, et al. "The environmentally benign synthesis of nanosized Co< sub> x Zn< sub> 1− x Al< sub> 2 O< sub> 4 blue pigments." Dyes and Pigments 87.2 (2010): 125-131.](http://old.icf.ro/PN_II/ECOPIG/CoxZn1-xal2O4.pdf)


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