Removal of synthetic food dyes in aqueous solution by Octolig®

Abstract

We studied six of the seven food dyes commonly used, e.g., FD&C Blue No. 1 and No. 2, Green No. 3, Red No. 3 and No. 40, Yellow No. 5 and No. 6. Quantitative removal was achieved by passage of dyes in aqueous solutions over chromatography columns packed with Octolig®, a polyethylenediimine covalently attached to high-surface-area silica. A structural feature most of the dyes have in common are the presence of sulfonate groups attached to aromatic molecules. Prior studies and the current one indicated that the seventh food dye (Green No. 3) should also be quantitatively removed. Matrix effects were considered, but none were observed.

Keywords:

• Food dyes
• Octolig®
• chromatography
• behavioral problems
• Feingold diet

Acknowledgments

We gratefully acknowledge samples of Octolig® provided by Metre-General, Inc. by President Robert L. Alldredge (dec) and by Mr. Mark Alldredge. We are grateful to Dr. Randy Larsen for the access to the Shimadzu UV-240 IPC UV-Vis recording spectrophotometer in his laboratory. We thank Mr. John Seals, Laboratory Manager, for providing the dye samples and Ms. Marianne McDonough (University of South Florida Library Acquisitions) for providing a copy of a useful online article.