In fact, quite high variability was exhibited within validation parameters. Repeatability and reproducibility values are related to fortification levels of 100 mg kg1 and 25 mg kg1 for group A and B respectively. In particular Table 2 reports validation parameters for red dyes. The same parameters were calculated for yellow dyes. The values were quite similar: E110 (sunset yellow) showed the best validation performances with a mean recovery more than 80% and RSDr and RSDR lower than 20%. On the other hand E102 (tartrazine) had the worst validation performances with a main recovery less
than 20%. In solid matrices, among red dyes (Table 2), amaranth
analysis showed rather low recoveries (60%) and quite high
repeatability and reproducibility values (both of them were over
than 30%). The best validation parameters among red dyes were
obtained from allura red (E129) that showed a mean recovery of
about 90% and repeatability and reproducibility parameters very
low.