A new spectrophotometric method for determination of EDTA in water using its complex with Mn(III)

Abstract

EDTA is an important ligand used in many industrial products as well as in agriculture, where it is employed to assist in phytoextraction procedures and the absorption of nutrients by plants. Due to its intensive use and recalcitrance, it is now considered an emerging pollutant in water, so there is great interest in techniques suitable for its monitoring. This work proposes a method based on formation of the Mn(III)-EDTA complex after oxidation of the Mn(II)-EDTA complex by PbO2 immobilized on cyanoacrylate spheres. A design of experiments (DOE) based on the Doehlert matrix was used to determine the optimum conditions of the method, and the influence of the variables was evaluated using a multiple linear regression (MLR) model. The optimized method presented a linear response in the range from 0.77 to 100.0μmolL(-1), with analytical sensitivity of 7.7×10(3)Lmol(-1), a coefficient of determination of 0.999, and a limit of detection of 0.23μmolL(-1). The method was applied using samples fortified at different concentration levels, and the recoveries achieved were between 97.0 and 104.9%.

A perspective on manganese-based flow batteries

“…EDTA can coordinate with Mn 2+ ion through its carboxyl and amino groups [43]. The density-functional-theory calculations demonstrate that the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of [Mn(EDTA)] 2− is greater than that of [Mn(H 2 O) 6 ] 2+ (figure 1(g)) [36].…”

Levantamento de resíduos de laboratórios, propostas de atividades experimentais e ações com foco em química verde

“…Dentre estes, destaca-se um solvente bastante utilizado em aulas experimentais, o ácido etilenodiaminotetracético (EDTA), que possui uma DL50 considerada regular e que também apresenta risco de contaminação ao meio ambiente. Uma vez que, se descartado incorretamente, este reagente pode formar complexos estáveis com íons metálicos do meio, sendo hoje considerado como um poluente emergente (ANDRADE et al, 2016), pois pode causar danos ao meio ambiente.…”