Food colorings include both artificial compounds and natural compounds. The high-performance liquid chromatograph (HPLC) is the most powerful analysis tool in this field. The figure below shows the simultaneous analysis of 33 water-soluble tar-coloring components at multiple wavelengths. The photodiode array detector enables simultaneous multi-wavelength analysis and obtains spectra for more accurate analysis and identification of unknown components.
A high-performance liquid chromatograph (HPLC) measures the content of various components in a sample. A liquid medium flows through the HPLC flow channel. When a sample is introduced into the instrument, the components of the sample are separated in a column and the amount of each component is measured by a detector. HPLC can handle a much wider range of target samples and components than GC, including difficult-to-vaporize and heat-sensitive components.
Use a system incorporating a UV or PDA detector for this analysis. (The photo shows a system with a PDA detector.)