Many analytical techniques have been developed for the identification
and quantification of various synthetic food colorants, such as spectrometry thin-layer chromatography (TLC), adsorptive voltammetry, and differential pulse chromatography.However, all of them present major drawbacks
as they require time-consuming extensive pretreatment of
the samples or/and cannot be applied to complex colorant mixtures.
To overcome these limitations, the use of capillary electrophoresis
(CE) and ion chromatography (IC) techniques has been
proposed as an alternative. However, the small injection volumes
utilized in those techniques and/or background noise, results to
sensitivity problems limiting the robustness of these methods.
High-performance reversed-phase liquid chromatography and ion-pair liquid chromatography coupled with UV or diode-array detectors (DAD) are currently
the most preferred analytical techniques as they provide
excellent robustness combined with unrivalled resolution, sensitivity
and selectivity.