Determination of 18 water-soluble artificial dyes by LC-MS in selected matrices

A multi-residue method based on two different extraction procedures was developed and compared with liquid chromatography electrospray ionization tandem mass spectrometry analysis of eighteen water-soluble artificial colours including Tartrazine (E102), Chrysoine (E103), Quinoline Yellow (E104), Yellow 2G (E107), Sunset Yellow (E110), Azorubine (E122), Amaranth (E123), Ponceau 4R (E124), Erythrosine (E127), Red 2G (E128), Allura Red (E129), Patent Blue V (E131), Indigo Carmine (E132), Brilliant Blue (E133), Green S (E142), Fast Green (E143), Brilliant Black (E151), and Black 7984 (E152) in sugar and gummy confectionary, ice-cream, and chocolate sweets. Sample preparation included SPE clean-up and liquid-liquid extraction for ice-cream and chocolate sweets. Accuracy was evaluated by recovery experiments. Correlation between response and concentration was obtained with R(2)>0.98 for all but six colours. Limits of quantification were within the 10-50 μg/kg range for E129; 20-200 μg/kg for E152; 10-250 μg/kg for E103; 10-500 μg/kg for E102, E104, E107, E110, E122, E123, E124, E127, E128, E131, E133; 20-800 μg/kg for E132, 142, 151; and 10-1000 μg/kg for E143. CV for repeatability ranged from 4.0% to 51.0%, while the CV for intermediate reproducibility ranged from 5.8% to 41.4%. Finally, recoveries varied from 84.3% to 166.0%. Together, these demonstrate that the method has been validated for complex matrices and is, thus, fit-for-purpose.