Artigo
Quantification of paramagnetic ions in solution using time domain NMR. PROS and CONS to optical emission spectrometry method
Fecha
2018Registro en:
Microchemical Journal. Amsterdam, v. 137, p. 204-207, 2018.
0026-265X
10.1016/j.microc.2017.10.013
WOS:000423894800028
Autor
Kock, Flavio Vinícius Crizóstomo
Machado, Maiara Pereira
Athayde, Geisamanda Pedrini Brandão
Colnago, Luiz Alberto
Barbosa, Lúcio Leonel [UNIFESP]
Institución
Resumen
Solutions containing paramagnetic ions (PMIs) have been widely used in several industrial and agricultural applications. Although the concentrations of these ions in solutions are very important, they are rarely checked due to the high cost of the measurements. In this paper, we demonstrate the viability of 2 MHz time-domain nuclear magnetic resonance (TD-NMR) relaxometer to quantify PMIs in solution. The method was used to quantify the concentration of Co2+, Cr3+, Cu2+, Fe3+ and Mn2+ and is based on linear correlation between the transverse relaxation rate (T-2(-1)) of the hydrogens of water and PMIs concentration. The method was validated using inductively coupled plasma optical emission spectrometry (ICP-OES), which is the standard method for quantitative elemental analyses. The concentration of PMIs were analyzed between 0.5 and 10 mg.L-1, with r(2) >= 0.99 between the two methods. Although the limits of detection (LOD) and quantification (LOQ) of TD-NMR are several orders of magnitude higher than those of ICP-OES, they are in the range of concentration normally found in commercial applications. Therefore, this work demonstrate that TD-NMR can be an affordable alternative for certificate the concentration of PMIs concentration in small laboratory in industrial or agricultural facilities. (C) 2017 Elsevier B.V. All rights reserved.