Development and evaluation of an HPLC-DAD method for determination of synthetic food colorants

As a result of recent European Union regulations food colorants must be determined quantitatively, not just qualitatively as in the past. We demonstrate that a mixture of 14 synthetic food colorants (E 102, E 104, E 110, E 122, E 123, E 124, E 127 E 128, E 129, E 131, E 132, E 133, E 142, and E 151) can best be resolved by use of a Purospher RP18e column (125 mm x 4 mm i.c., 5 mum particle) and a gradient prepared from 100 mm acetate buffer (pH 70) and acetonitrile. Diode-array detection was used to monitor the colorants; limits of detection ranged from 0.02 ng (E 142) to 2.05 ng (E 132) at a signal-to-noise ratio of 3.