Food additives are chemical substances added to improve organoleptic characteristics, in this context, there are several synthetic dyes, such as sunset yellow, tartrazine, erioglaucine, allura red, indigo carmine, and new coccine, that can also be identified through different analytical techniques such as infrared spectroscopy, UV-Vis spectrophotometry, high performance liquid chromatography with diode array detector and mass spectrometry. Therefore, the objective of this work was to compare methods developed for different analytical techniques, in order to identify the one that presents greater efficiency in certain applications. For this, the patterns of the dyes were analyzed, as well as their mixtures and foods that had them. As a result, the CLAE-DAD presents excellent selectivity and linearity of the calibration curves, but it presents higher LD and LQ values when compared to the UV-Vis, in turn the infrared provides information regarding functional groups and bonds. Mass spectrometry showed great capabilities in identifying the molecular formula and better selectivity in the absence of the erioglaucine dye. It is not feasible to indicate the best or worst analytical approach, but it is possible to point out which one is more suitable for each application. Regarding the quantification capacity, chromatography and UV-Vis are good alternatives, but in mixtures containing more than one dye, CLAE-DAD is more suitable due to the better selectivity. Regarding the identification capacity, mass spectrometry, especially FT-ICR MS, is the most appropriate technique to propose molecular formulas due to its high resolution and mass accuracy. The advantage of FTIR was the easier sample preparation, being able to analyze the dyes in the solid state.

Mass spectrometry (MS) is a high-performance analytical technique that allows a measurement of the mass/charge (m/z) ratio of compounds present in a sample. MS is able to separate two m/z ions with determined values (mass resolution), being an important characteristic, especially in the analysis of biochemical components and complex mixtures. Mass analyzers define the resolving power and accuracy of different types of mass spectrometers. Herein, the performance of two mass analyzers (Fourier Transform Ion Cyclotronic Resonance (FT-ICR) and quadrupole ion trap (LTQ)) was tested on low (Mw = 165-679 Da) and high (Mw = 783-8.58 kDa) molecular weight molecules (Phenacetin, Procaine, Benzocaine, Caffeine anhydrous, Lidocaine, two metal porphyrin standards, the first cobalt and the second vanadium, and two protein standards, Ubiquitin and Beauvericin), and finally, for an oil sample. LTQ-MS and FT-ICR-MS had similar performance and high reproducibility. However, the mass accuracy and resolution power of the FT-ICR (error lower than 5 ppm and RP higher than 400,000) was higher, being therefore, it was more suitable for the analysis of proteins and oil, for instance. On the other hand, the CID analysis via LTQ demonstrated its applicability in fragmentation experiments, being able to determinate the chemical connectivity of organic compounds in non-complex mixtures.