Aminoguanidine hydrazones (AGHs) are a class of compounds that have interesting pharmacological activities. They are derived from the same chemical group as aminoguanidine, so it has mixed properties (receptor and don...Aminoguanidine hydrazones (AGHs) are a class of compounds that have interesting pharmacological activities. They are derived from the same chemical group as aminoguanidine, so it has mixed properties (receptor and donor) in the formation of hydrogen bonds. Its anticancer agent properties were recently highlighted, but the molecules of this class have solubility in aqueous solutions that can be considered low. The identification of this class, by a simple, sensitive and low-cost technique, such as electrochemistry, which also allows the evaluation of its solubilization process through agents such as PAMAM dendrimer is the main objective of the work described here. The electrochemical response of the LQM10 (AGH derivative) was evaluated, as well as its behavior in different electrochemical sensors. Electrochemical experiments were performed in buffered (phosphate at pH 7.02 and acetate at 4.5). LQM10 has a reversible oxidation peak with a potential of +0.22 V. It was efficiently detected in different electrodes tested (glass carbon/CNT, glass carbon/CNT/PAMAM), which proves the viability of the electrodes for various analyses and has the determination of the apparent constant association, indicating its interaction with the analysis that is higher in the presence of the PAMAM encapsulating agent. This was corroborated by the results for the modified gold electrode with MUA and PAMAM. The sum of the results shows the possibility of electrochemically evaluating the Aminoguanidine hydrazone derivative, the viability of electrodes employed and the greater solubilization of LQM10 in the presence of the PAMAM dendrimer.展开更多
An alternative spectrophotometric method has been developed for total iron determination using flow injection analysis (FIA). The procedure is based on the coordination reaction between hydralazine and Fe2+ ions, whic...An alternative spectrophotometric method has been developed for total iron determination using flow injection analysis (FIA). The procedure is based on the coordination reaction between hydralazine and Fe2+ ions, which results in the formation of a purple complex monitored at 538 nm. For determination of total iron, Fe3+ ions were reduced using ascorbic acid. Under optimized conditions, a linear calibration graph (0.1 - 6.0 ?g?ml–1;n = 6) was obtained. The method allows LOD (3? of blank/slope = 0.06 ?g?ml–1) and LOQ (10? of blank/slope = 0.22 ?g?ml–1). The RSD ((s/ ) × 100) for a mixed standard containing 0.60 ?g?ml–1 Fe2+ and Fe3+ was 0.10% (n = 10). Recoveries of spiked samples were 94.3% - 106.0%. The analytical frequency was 60 h–1. The effect of possible interferences has been studied. The procedure was successfully applied for analysis of environmental samples. The real samples results were comparable with those obtained by the official method considering a paired t-test and 95% of confidence level.展开更多
基金Brazilian agencies CNPq,CAPES,FAPEAL and UFAL for financial support
文摘Aminoguanidine hydrazones (AGHs) are a class of compounds that have interesting pharmacological activities. They are derived from the same chemical group as aminoguanidine, so it has mixed properties (receptor and donor) in the formation of hydrogen bonds. Its anticancer agent properties were recently highlighted, but the molecules of this class have solubility in aqueous solutions that can be considered low. The identification of this class, by a simple, sensitive and low-cost technique, such as electrochemistry, which also allows the evaluation of its solubilization process through agents such as PAMAM dendrimer is the main objective of the work described here. The electrochemical response of the LQM10 (AGH derivative) was evaluated, as well as its behavior in different electrochemical sensors. Electrochemical experiments were performed in buffered (phosphate at pH 7.02 and acetate at 4.5). LQM10 has a reversible oxidation peak with a potential of +0.22 V. It was efficiently detected in different electrodes tested (glass carbon/CNT, glass carbon/CNT/PAMAM), which proves the viability of the electrodes for various analyses and has the determination of the apparent constant association, indicating its interaction with the analysis that is higher in the presence of the PAMAM encapsulating agent. This was corroborated by the results for the modified gold electrode with MUA and PAMAM. The sum of the results shows the possibility of electrochemically evaluating the Aminoguanidine hydrazone derivative, the viability of electrodes employed and the greater solubilization of LQM10 in the presence of the PAMAM dendrimer.
基金Financial support from CNPq,CNPq/CTHIDRO,CAPES and FAPEAL(Brazil)
文摘An alternative spectrophotometric method has been developed for total iron determination using flow injection analysis (FIA). The procedure is based on the coordination reaction between hydralazine and Fe2+ ions, which results in the formation of a purple complex monitored at 538 nm. For determination of total iron, Fe3+ ions were reduced using ascorbic acid. Under optimized conditions, a linear calibration graph (0.1 - 6.0 ?g?ml–1;n = 6) was obtained. The method allows LOD (3? of blank/slope = 0.06 ?g?ml–1) and LOQ (10? of blank/slope = 0.22 ?g?ml–1). The RSD ((s/ ) × 100) for a mixed standard containing 0.60 ?g?ml–1 Fe2+ and Fe3+ was 0.10% (n = 10). Recoveries of spiked samples were 94.3% - 106.0%. The analytical frequency was 60 h–1. The effect of possible interferences has been studied. The procedure was successfully applied for analysis of environmental samples. The real samples results were comparable with those obtained by the official method considering a paired t-test and 95% of confidence level.
