Iron is a fundamental microelement for human life; however, deficiencies or excesses of these metal ions can cause severe complications and mortality. Chelators are compounds that bind and inhibit iron. Ultraviolet-visible (UV-vis) spectrophotometric methods are key analytical tools in the identification of chemical entities, with the benefits of having good precision and accuracy, and the equipment being easily available as well as quick and simple to implement. In this study, we aimed to provide an alternative, cheaper method for the quantification of iron ion chelation by substituting ferrozine for gallic acid and validating its use with UV-vis according to official ANVISA and ICH guidelines. The parameters assessed were specificity, linearity, precision, accuracy, robustness, and finally, the percentage of iron ions chelating was calculated. The results demonstrated that this method was accurate, simple, specific, selective, precise, and reproducible, and was successfully validated for the determination of iron ions chelating. The percentage of iron ions chelating, promoted by the standard chelator EDTA, was 45% and 47% for Fe2+ and Fe3+, respectively. It is concluded that this new method is beneficial in terms of its simplicity, rapidness, low cost, and the fact that it produces very low levels of dangerous residues.

In this study, the effect of sucrose on the neutral lipid profile of adventitious root cultures of Stevia rebaudiana was evaluated. The cultures were obtained employing a roller bottle system. In this system, Schott-type flasks were used, which contained Murashige and Skoog liquid medium at 33.3% strength (MS/3) supplemented with 30, 60, and 80 g L-1 of sucrose, respectively, and 10.7 mM 1-naphthaleneacetic acid (NAA). The spectroscopic analyzes showed that the portion of polyunsaturated fatty acids (PUFAs) was highest in roots treated with 30 g L-1 of sucrose. The spectrometric analyzes showed that the palmitic acid was found to be present in relatively higher amounts in the roots submitted to the MS/3-30 g L-1 (31.9%) and MS/3-60 g L-1 (29.5%) sucrose treatments, and lower in the treatment with MS/3-80 g L-1 (28.8%) of sucrose. Also, the treatment using 30 g L-1 of sucrose was the best for obtaining unsaturated fatty acids (UFAs) in the culture, with a relative percentage of 62.9%. Our results indicate that the MS medium that received 30 g L-1 of sucrose induced a lesser abiotic stress condition, which favored PUFAs production in the adventitious root cultures of S. rebaudiana.