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Indigo Carmine in a Food Dye: Spectroscopic Characterization and Determining Its Micro-Concentration through the Clock Reaction

Authors :
Maja C. Pagnacco
Jelena P. Maksimović
Nenad T. Nikolić
Danica V. Bajuk Bogdanović
Milan M. Kragović
Marija D. Stojmenović
Stevan N. Blagojević
Jelena V. Senćanski
Source :
Molecules; Volume 27; Issue 15; Pages: 4853, Molecules
Publication Year :
2022
Publisher :
Multidisciplinary Digital Publishing Institute, 2022.

Abstract

Indigo carmine is a commonly used industrial blue dye. To determine its concentration in a commercially available food dye composed of a mixture of indigo carmine and D-glucose, this paper characterizes it through (ATR, KBr) FTIR micro-Raman as well as UV/Vis and clock: Briggs–Rauscher (BR) oscillatory reaction methods. The indigo carmine was detected in the bulk food dye only by applying micro-Raman spectroscopy, indicating a low percentage of the indigo carmine present. This research provides an improvement in the deviations from the experimental Raman spectrum as calculated by the B97D/cc-pVTZ level of theory one, resulting in a better geometrical optimization of the indigo carmine molecule compared to data within the literature. The analytical curves used to determine indigo carmine concentrations (and quantities) in an aqueous solution of food dye were applied by means of UV/Vis and BR methods. BR yielded significantly better analytical parameters: 100 times lower LOD and LOQ compared to commonly used UV/Vis. The remarkable sensitivity of the BR reaction towards indigo carmine suggests that not only does indigo carmine react in an oscillatory reaction but also its decomposition products, meaning that the multiple oxidation reactions have an important role in the BR’s indigo carmine mechanism. The novelty of this research is the investigation of indigo carmine using a clock BR reaction, opening new possibilities to determine indigo carmine in other complex samples (pharmaceutical, food, etc.).

Details

Language :
English
ISSN :
14203049
Database :
OpenAIRE
Journal :
Molecules; Volume 27; Issue 15; Pages: 4853
Accession number :
edsair.doi.dedup.....4ebf494c091d9d76b0aed7f0a353c093
Full Text :
https://doi.org/10.3390/molecules27154853