The precision was evaluated by repeatability and the intermediate precision estimates and by Horrat value (AOAC, 2012; González, Herrador, & Asuero, 2010). In repeatability tests, three solutions of each food (S1 and CS1 samples) were prepared as described above and analyzed in the same day. Relative standard deviations (RSDs) were calculated from data in triplicate and were used as a repeatability estimate. The intermediate precision tests were carried out in the same way as the repeatability tests during f ive consecutive days. Relative standard deviations (RSDs) from data were calculated again and used as intermediate precision estimates. Horrat values were also obtained, using the results of an analysis of variance (ANOVA) characteristic of hierarchical design at 95% confidence level, as a way to verify the suitability of intermediate precision estimates for the chromatographic methodology.