DETERMINATION OF SYNTHETIC FOOD DYES BY CAPILLARY ELECTROPHORESIS

A method for the determination of synthetic tar dyes used as food addi tives using capillary electrophoresis with photodiode-array detection was investigated. The dyes Erythrosine (R-3), Phloxine (R-104), Rose B engal (R-105), Acid Red (R-106), Amaranth (R-2), New Coccine (R-102) a nd Allura Red AC (R-40) were separated on a capillary column (50 cm x 75 mu m I.D.) and identified from the absorbance spectra of each peak. The electrophoresis buffer used was a mixture of 25 mM sodium phospha te buffer and 25 mM sodium berate buffer (1:1) (pH 8.0) containing 10 mM sodium dodecyl sulfate (SDS). Substitution of beta-cyclodextrin for SDS in the electrolyte buffer was effective for the separation of R-2 and R-102. This modified method could be employed as an additional as say method for these two dyes.