QUANTITATIVE-DETERMINATION OF AZORUBINE W ITH TETRABUTYLAMMONIUM BROMIDE

This paper describes a new method for the quantitative determination o f the sulfonated azo dye azorubine. The quaternary ammonium compound t etrabutylammonium bromide and azorubine form stoichiometrically compos ed ion pairs, which can be extracted quantitatively from an aqueous ph ase. As standardization of the dye content of a chemical reference sub stance of azorubine involves problems, a linear calibration was carrie d out for tetrabutylammoniumbromide. Afterwards the azorubine test sol ution was extracted and its content was calculated refering to the mol ar composition of the ion pair.