A Reverse Phase HPLC Method to Determine Six Food Dyes Using Buffered Mobile Phase.

Abstract

A reverse phase high performance liquid chromatographic (HPLC) method to determine six food dyes (Sunset Yellow (E-110), Carminic acid (E-120) Carmoisine (E-122), Amaranth (E-123), Ponceau 4R (E-124) and Erythrosine (E-127) is developed in this paper. The separation was made on a Nova-Pack C18 column using methanol -NaH₂PO₄/Na₂HPO₄ pH=7 buffer solution 0.1M as mobile phase with an elution gradient system. The detection was made with a variable UV-Vis. detector fixed at 520 nm.

The effect of mobile phase composition such as the percentage of methanol or acetonitrile, pH value and ionic strength on retention times of the dyes was investigated. In the chromatographic conditions selected, the dyes were eluted in four minutes. Two calibration graphs for each dye were established by measuring the peak area and the peak height in the chromatograms. Determination limits ranging from 0.8 to 9.2 ng were obtained when the peak area was measured.

Several commercial products containing some of these dyes were analyzed.

Key Words:

• Food Dyes
• HPLC
• Reverse Phase
• Buffered Double Phase