Measuring the solubility product constant of paramagnetic cations using time-domain nuclear magnetic resonance relaxometry

Cobra, Paulo Falco; Gomes, Bruna Ferreira; Mitre, Cirlei Igreja Nascimento; Barbosa, Lúcio L.; Marconcini, L. V.; Colnago, Luiz Alberto

doi:10.1016/j.microc.2015.02.002

Cited by 27 publications

(17 citation statements)

References 12 publications

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“…Above this pH, the T 1 values were approximately equal T 2 , due to the Mn(OH) 2 suspension does not interfere in water relaxation, showing values close to pure water, as aforementioned discussed[24].The T 1 and T 2 values, in presence of EDTA, show a sharp increases from pH 2.5 to 4. These results shows the gradual transition in solution from complex structure [Mn(H 2 O) 6 ] 2+ to Mn(II)-EDTA, increasing progressively the T 1 and T 2 values as consequence of water remotion near to metal in the inner coordination sphere.…”

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confidence: 66%

Rapid and simultaneous relaxometric methods to study paramagnetic ion complexes in solution: An alternative to spectrophotometry

Kock

Colnago

2015

Microchemical Journal

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supporting

confidence: 66%

Rapid and simultaneous relaxometric methods to study paramagnetic ion complexes in solution: An alternative to spectrophotometry

Kock

Colnago

2015

Microchemical Journal

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“…The interactions between CHI and the paramagnetic ions Fe 3+ , Cu 2+ , and Mn 2+ were studied as functions of pH using TD-NMR relaxometry. These paramagnetic ions were chosen because they precipitate as hydroxides in aqueous solutions at pH values 3.2, 7.0, and 9.3, respectively [16]. Therefore, their interactions with CHI may be studied in a broad pH range.…”

Section: Resultsmentioning

confidence: 99%

“…To the best of our knowledge, no studies involving CHI-metal ions have been performed using low-field, time-domain nuclear magnetic resonance (TD-NMR) relaxometry. We have recently demonstrated that TD-NMR relaxometry can be a simple, rapid method to measure CHI coagulation [15] and solubility product constant [16] as well as to monitor the complexation of paramagnetic ions in solution [17], even in cases where the equipment has instrumental limitation, as long dead time [18]. All these relaxometric studies have been performed as functions of solution pH.…”

Section: Introductionmentioning

confidence: 99%

Time-domain NMR relaxometry as an alternative method for analysis of chitosan-paramagnetic ion interactions in solution

Kock

Monaretto

Colnago

2017

International Journal of Biological Macromolecules

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Chitosan (CHI)-paramagnetic ion interactions in aqueous solution as affected by pH were studied using time-domain NMR (TD-NMR) relaxometry. Longitudinal (T) and transverse (T) relaxation times of CHI solutions with Fe, Cu, and Mn were measured using a single-shot pulse sequence named CP-CWFP. The results indicate that CHI interacted with Fe ions or iron oxide nanoparticles, maintaining the metal ion in solution at pH ranging from 3 to 5. Above this pH, CHI coagulated and removed Fe ions or nanoparticles, resulting in a clear supernatant. CHI probably interacted with Cu ions at pH 6.2 through the deprotonated CHI-NH groups maintaining the relaxation effect in alkaline solution, whereas Mn did not interact with CHI strongly enough to produce a complex of high stability. The proposed method can also be further exploited in the study of interactions paramagnetic ions with others CHI and CHI derivatives as well as of other water-soluble polysaccharides.

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“…The linear relationship between the relaxation rate (1 T 2 ) and the concentration of paramagnetic ions has been exploited to quantify paramagnetic ions in solutions, to calculate K SP values [23], to study coordination complexes with paramagnetic ions as ligands [24] and also to monitor electrochemical reactions in situ [8,9].…”

Section: Magnet Type Lod (Mol⋅lmentioning

confidence: 99%

Monitoring Electrochemical Reactions in Situ with Low Field NMR: A Mini-Review

2019

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The number of applications of time domain NMR using low-field spectrometers in research and development has been steadily increasing in recent years with applications ranging from quality control of industrial products to the study of physical and chemical properties of a wide array of solid and liquid samples to, most recently, electrochemical studies. In this mini-review we summarize the progress that has been achieved in the coupling between time domain NMR (using low-field spectrometers) and electrochemistry and how the challenges that this coupling poses have been overcome over the years. We also highlight the effect that the static magnetic field of the NMR spectrometer has on the electrochemical systems.

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Measuring the solubility product constant of paramagnetic cations using time-domain nuclear magnetic resonance relaxometry

Cited by 27 publications

References 12 publications

Rapid and simultaneous relaxometric methods to study paramagnetic ion complexes in solution: An alternative to spectrophotometry

Rapid and simultaneous relaxometric methods to study paramagnetic ion complexes in solution: An alternative to spectrophotometry

Time-domain NMR relaxometry as an alternative method for analysis of chitosan-paramagnetic ion interactions in solution

Monitoring Electrochemical Reactions in Situ with Low Field NMR: A Mini-Review

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