Sodium-23 Nuclear Magnetic Resonance Research Articles

Can sodium NMR provide more than a tracer for brine in petrophysics?

Sodium has been suggested as a tracer for brine in reservoir formations, where sodium ions are found exclusively in the aqueous phase, and can be detected by time-domain nuclear magnetic resonance (NMR). To date, petrophysical applications of sodium-23 NMR have focused on concentrated NaCl electrolyte solutions where the nuclear spin relaxation time is related to ion concentration. Therefore, a measure of brine volume is achieved directly from the sodium signal amplitude and relaxation time, available in a single measurement. However, real reservoir formation or injection brines contain many different ionic moieties. Sodium-23 relaxation times and diffusion coefficients are measured using time-domain NMR and pulsed field gradient (PFG) NMR techniques, respectively, and shown to depend strongly on the ions present in solution. Correlations between sodium-23 relaxation times and sodium ion concentration are found to differ depending on the cations and other anions present in the brine. However, consistent correlations are obtained for sodium-23 relaxation times and diffusion coefficient, and brine viscosity, regardless of the ionic content of the brine. In general, sodium-23 NMR remains a qualitative technique for monitoring changes in sodium concentration or brine volume (at constant salinity) in reservoir formations. However, if knowledge of the brine chemistry is available, then sodium-23 NMR offers a non-invasive and quantitative method of robustly measuring brine volume and viscosity in petrophysical applications.

Energy profiles for sodium ion passage through the single-filing gramicidin transmembrane channel

Sodium-23 nuclear magnetic resonance longitudinal and transverse relaxation studies of sodium ion interaction with the Gramicidin A transmembrane channel are reported in the 30d to 75d temperature range to determine the temperature dependence of the off-rate constant for the doubly occupied channel (kwoff) of the binding constant for going from single to double ion occupancy (Kwb), of the binding constant for going from empty to singly occupied channel (Ktb), and of the off-rate constant for the singly occupied channel, (kkoff). With previous information for the temperature dependence of the intrachannel rate constant for an ion going from one ion binding site to the other (kk) for the singly occupied state of this two-fold symmetric channel, the enthalpy (ΔH and the –TΔS energy profiles are plotted for ion passage through the channel. This provides energy profiles for comparison with theoretical calculations. Comparison of TΔS values defined by equilibrium theory (i.e. entropy changes on going from one minimum to another) with the TΔS values defined by Eyring rate theory (i.e. the entropy change between minima and activated state) shows that, even though Eyring rate theory has the very large pre-exponential factor (kT/h), the changes in entropy obtained from the temperature dependence of equilibrium constants are very nearly the same as the changes in entropy obtained from the temperature dependence of the off-rate constants. Thus application of Eyring rate theory to single filling channels, where the channel wall supplies lateral coordinations of the permeant ion and where the rate constants are of the order of 107 ions/sec, appears quite reasonable.

Sodium-23 and lanthanum-139 nuclear magnetic resonance studies of cation binding to aqualysin I, a thermostable serine protease.

Aqualysin I has at least two Ca2+-binding sites that have different affinities for Ca2+. The binding of various metal ions to aqualysin I was studied using 23Na- and 139La-NMR spectrometry. Evidence is presented that Ca2+, La3+, and Na+ bind to the low-affinity Ca2+-binding site of aqualysin I, but Mg2+ does not. Our results confirm that binding of metals at the low-affinity Ca2+-binding site is essential for thermostabilization, since the addition of Mg2+ did not result in thermostabilization. La3+ was found to bind to both the low-affinity Ca2+-binding site and an additional metal ion-binding site that can also be involved in the thermostabilization of aqualysin I.

The structure of tellurite glass: a combined NMR, neutron diffraction, and X-ray diffraction study

Models are presented of sodium tellurite glasses in the composition range (Na 2O) x –(TeO 2) 1− x , 0.1< x<0.3. The models combine self-consistently data from three different and complementary sources: sodium-23 nuclear magnetic resonance (NMR), neutron diffraction, and X-ray diffraction. The models were generated using the Reverse Monte Carlo algorithm, modified to include NMR data in addition to diffraction data. The presence in the models of all five tellurite polyhedra consistent with the Te 4+ oxidation state were found to be necessary to achieve agreement with the data. The distribution of polyhedra among these types varied from a dominance of bridged species at lower sodium contents, to polyhedra with one or zero bridging oxygen at larger sodium contents. The models indicate that the sodium cations themselves form sodium oxide clusters particularly at the x=0.2 composition.

Sodium-23 NMR and complex impedance studies of gel electrolytes based on poly (acrylonitrile)

Highly conducting gel electrolytes prepared from mixtures of poly (acrylonitrile) (PAN), ethylene carbonate (EC), propylene carbonate (PC) and NaClO 4 have been studied by complex impedance, differential scanning calorimetry (DSC) and 23Na nuclear magnetic resonance (NMR) spectroscopy. Ionic motional correlation times spanning nearly five orders of magnitude, probed by temperature-dependent dynamical features of the 23Na quadrupole-broadened NMR lineshape, are strongly influenced by the single glass transition temperature observed in the gel electrolyte. Dielectric measurements of mixtures of PAN, EC and PC suggest that the polar nitrile group in PAN may interact with Na + ions in the gel. All results are consistent with the conclusion that PAN provides stability to the gel network down to the immediate vicinity of the Na + ions, rather than acting as a rigid framework for regions of liquid electrolyte.

Sodium-23 and potassium-39 nuclear magnetic resonance relaxation in eye lens. Examples of quadrupole ion magnetic relaxation in a crowded protein environment

Single and multiple quantum nuclear magnetic resonance (NMR) spectroscopic techniques were used to investigate the motional dynamics of sodium and potassium ions in concentrated protein solution, represented in this study by cortical and nuclear bovine lens tissue homogenates. Both ions displayed homogeneous biexponential magnetic relaxation behavior. Furthermore, the NMR relaxation behavior of these ions in lens homogenates was consistent either with a model that assumed the occurrence of two predominant ionic populations, "free" and "bound," in fast exchange with each other or with a model that assumed an asymmetric Gaussian distribution of correlation times. Regardless of the model employed, both ions were found to occur in a predominantly "free" or "unbound" rapidly reorienting state. The fraction of "bound" 23Na+, assuming a discrete two-site model, was approximately 0.006 and 0.017 for cortical and nuclear homogenates, respectively. Corresponding values for 39K+ were 0.003 and 0.007, respectively. Estimated values for the fraction of "bound" 23Na+ or 39K+ obtained from the distribution model (tau C greater than omega L-1) were less than or equal to 0.05 for all cases examined. The correlation times of the "bound" ions, derived using either a two-site or distribution model, yielded values that were at least one order of magnitude smaller than the reorientational motion of the constituent lens proteins. This observation implies that the apparent correlation time for ion binding is dominated by processes other than protein reorientational motion, most likely fast exchange between "free" and "bound" environments. The results of NMR visibility studies were consistent with the above findings, in agreement with other studies performed by non-NMR methods. These studies, in combination with those presented in the literature, suggest that the most likely role for sodium and potassium ions in the lens appears to be the regulation of cell volume by affecting the intralenticular water chemical potential.

Analysis of sodium-23 nuclear magnetic resonance spin-lattice relaxation for the study of the intracellular sodium state

Sodium-23 Nuclear Magnetic Resonance relaxation spectroscopy has been used to investigate the state of intracellular Na + in control and CCl 4-tr

23Na-NMR measurements of the sodium concentration in guinea pig erythrocytes: the effects of cardiac glycoside and asebotoxin III

Intra- and extracellular sodium in guinea pig erythrocytes was evaluated with sodium-23 nuclear magnetic resonance (23Na-NMR) by the use of a shift reagent, Dy(TTHA)3- or Dy(PPPi)2(7-). The test medium contained erythrocytes at 40% hematocrit level and NMR buffer (145 mM NaCl, 10 mM Dy(TTHA)3-, 10% D2O, adjusted to pH 7.4 with tris, at 35 degrees C). NMR spectra were obtained with a JEOL GSX 400 spectrometer operating at the Fourier transform mode of resonance signals, and the accumulated signals provoked by radio-frequency pulses of 90 degrees were recorded on paper. Quantitative Na determination was performed by measuring the area under the peak of intracellular sodium (Nai) NMR signals. Ouabain (Oua: 0.3 mM) and asebotoxin-III (ATX-III: 0.3 mM) produced an increase in Nai-NMR signals to a level of 188.1% and 138.1% of the control, respectively. Combined use of Oua (0.15 mM) and ATX-III (0.15 mM) produced an elevation of Nai concentration to a high level of 219.0% of the control in a superadditive manner. Mechanisms of the Nai elevation with Oua and ATX-III can be interpreted by assuming two different actions: ATX-III increases net Na(+)-influx via Na+ channels, while Oua inhibits the pumping out of Na+ from the cell.

Influence of Cardiac Pacing on Intracellular Sodium in the Isolated Perfused Rat Heart

Increased myocardial contractile tension has been described as being associated with increased heart rate. This phenomenon is believed due to greater sodium influx than efflux, resulting in accumulation of intracellular sodium. Sodium-23 nuclear magnetic resonance spectroscopy in combination with extracellular shift reagents offers near-continuous measurements of intracellular sodium that may be correlated with mechanical performance. In this study, the influence of cardiac pacing on intracellular sodium (Na+i), was examined in the isolated perfused rat heart using the paramagnetic shift reagent, Tm(DOTP)5-. The effect of changing heart rate on mechanical performance was measured using a pressure transducer-tipped catheter or a fluid-filled catheter during spectroscopic observation. There was no significant change in Na+i with increasing heart rate over a wide range of heart rates, and a fall in developed pressure with increasing heart rate (negative force-frequency relationship) was observed. It is concluded that the concentration of intracellular sodium monitored by this method is not sensitive to changes in heart rate.

Complexation of sodium(I) and other monovalent ions by 4,7,13,16-tetraoxa-1,10-diazabicyclo[8.8.2]eicosane in a range of solvents. A potentiometric titration and sodium-23 nuclear magnetic resonance study

Complexation of sodium(I) and other monovalent ions by 4,7,13,16-tetraoxa-1,10-diazabicyclo[8.8.2]eicosane in a range of solvents. A potentiometric titration and sodium-23 nuclear magnetic resonance study

Sodium-23 nuclear magnetic resonance imaging of the rabbit kidney in vivo

The mechanism by which the mammalian kidney generates a concentration gradient of sodium from cortex to papilla is still not entirely understood. Studies of how the kidney as an organ generates this gradient have been hampered by the lack of a noninvasive method for monitoring the intrarenal sodium distribution. Herein, we demonstrate the value of sodium-23 nuclear magnetic resonance (23Na-NMR) imaging to nondestructively assess the intrarenal sodium distribution. 23Na-NMR images were obtained from a surgically exposed kidney preparation that showed the two-dimensional distribution of sodium in the rabbit kidney. In the antidiuretic kidney this gradient resulted in papillary sodium concentrations that were approximately threefold higher than cortical values. Serial 23Na-NMR images obtained during saline infusion demonstrated the kinetics by which the sodium gradient increases with diuresis. The half-time for 23Na washout of the medulla of the kidney was approximately 6 min with this protocol. In addition, a three-dimensional data set of the sodium distribution of the kidney was obtained with voxel dimensions of 1.5 mm3 by use of a three-dimensional 23Na-NMR imaging technique. Without surgical exposure, 23Na-NMR images of the rabbit kidney were collected under completely noninvasive conditions by use of a surface coil. The 23Na-NMR signal from the kidney was easily detected; however, to obtain images of comparable signal-to-noise ratio to the surgically exposed kidney, spatial and temporal resolution were significantly reduced.

Sodium-23 and proton nuclear magnetic resonance imaging studies of carbon tetrachloride-induced liver damage in the rat

Magnetic resonance imaging techniques were used to investigate the response of the liver of the rat in situ to a toxicological challenge by carbon tetrachloride. Proton images were taken as transverse slices through the rat before and after intraperitoneal administration of the hepatotoxin. Two to three hours after carbon tetrachloride was given, a region of high proton signal intensity was observed where the portal vein enters the liver. Sodium-23 images were also taken, and a region of high sodium intensity was observed in the same location within the liver as the increased proton intensity. The results suggest that acute administration of carbon tetrachloride induces localized liver damage in the region where the hepatotoxin first enters the liver. This liver damage is manifest as edema with a buildup of sodium ion and water, which can be readily detected by sodium-23 and proton NMR imaging techniques, respectively.

Clinical application of sodium-23 nuclear magnetic resonance for measurement of red cell sodium concentrations

Red cell sodium (RBC-Na+) concentrations were measured using 23Na nuclear magnetic resonance (NMR), without the destruction of erythrocyte membranes. Subjects were categorized into four groups: 20 normotensive subjects (NT group), 20 age-matched essential hypertensive patients (EHT group), 10 patients with primary aldosteronism (PA group), and 18 patients treated with digoxin (DIG group). Although RBC-Na+ concentrations were similar between the NT group (6.14±0.80 (Mean±SD) mmol/1) and the EHT group (5.92±0.99), they were significantly higher in both the PA group (7.55±0.88, p<0.001) and the DIG group (8.43±3.81, p<0.02). In the PA group, RBC-Na+ concentrations decreased significantly after resection of the adenoma, and there was an inverse relationship between serum potassium and RBC-Na+ concentrations (r=−0.65, p<0.01). In the DIG group, RBC-Na+ concentrations tended to increase in proportion to serum digoxin levels (r=0.53, p<0.05). These results support the view that RBC-Na+ concentrations are determined primarily by Na+/K+-pump activity of red cell membranes. This study showed also that Na+ NMR is an useful method determining intracellular Na+ concentrations.

The nature of a sodium–crown interaction studied by sodium-23 nuclear magnetic resonance and by crystal structure determination of a complex with co-ordinated solvent

New measurements were obtained by n.m.r. methods on the relaxation times of 23Na nuclei in ligand–metal salt solutions in pyridine–CH2Cl2(1 : 1) with the intention of modelling the rate processes in ion selective electrodes. Cation-exchange rates for some propeller crowns suggest the mechanism of Na exchange in the presence of excess sodium ions is dissociative. Sodium exchange rates are slower for more rigid propeller crowns. The solvated species are shown by means of a crystal structure to contain only one pyridine co-ordinated to sodium, but additional molecules of solvating pyridine are present in the crystal, and evident in elemental analyses. An additional sodium-containing species was discovered at temperatures of 230 K and below in this solvent. Results are of significance in relation to understanding the nature of cation–ionophore interaction in ion-selective electrodes and other selective devices.

Studies on the chemical modification of monensin. II. Measurement of sodium ion permeability of monensylamino acids using sodium-23 nuclear magnetic resonance spectroscopy.

A technique to assay Na+ ions in cells is presented. Intracellular and extracellular Na+ ions in a suspension of guinea pig erythrocytes were conveniently determined by using sodium-23 nuclear magnetic resonance (23Na-NMR), in combination with two anionic shift reagents: Dy(TTHA)3- and Dy(PPPi)2(7-). Monensin (1), monensylalanine (2b), monensylserine (2c), and monensylphenylalanine (2d) induced large increases of intracellular Na+ ion concentration ([Nain]), while monensylglycine (2a), monensyltyrosine (2e), monensylaspartic acid (2f), and monensylglutamic acid (2g) showed slight increases. The values of initial increasing rate (Vi) of 2a-g were much smaller than that of 1. This fact was probably due to the lower lipophilicity of 2a-g than 1, because a good correlation was observed between Vi and Rm50 values of 1 and 2a-g. This lower lipophilicity is a consequence of conformational differences between 1 and 2a-g.

Clinical application of sodium-23 nuclear magnetic resonance for measurement of red cell sodium concentrations

Red cell sodium (RBC-Na+) concentrations were measured using 23Na nuclear magnetic resonance (NMR), without the destruction of erythrocyte membranes. Subjects were categorized into four groups: 20 normotensive subjects (NT group), 20 age-matched essential hypertensive patients (EHT group), 10 patients with primary aldosteronism (PA group), and 18 patients treated with digoxin (DIG group). Although RBC-Na+ concentrations were similar between the NT group (6.14 +/- 0.80 (Mean +/- SD) mmol/l) and the EHT group (5.92 +/- 0.99), they were significantly higher in both the PA group (7.55 +/- 0.88, p less than 0.001) and the DIG group (8.43 +/- 3.81, p less than 0.02). In the PA group, RBC-Na+ concentrations decreased significantly after resection of the adenoma, and there was an inverse relationship between serum potassium and RBC-Na+ concentrations (r = -0.65, p less than 0.01). In the DIG group, RBC-Na+ concentrations tended to increase in proportion to serum digoxin levels (r = 0.53, p less than 0.05). These results support the view that RBC-Na+ concentrations are determined primarily by Na+/K+-pump activity of red cell membranes. This study showed also that Na+ NMR is an useful method determining intracellular Na+ concentrations.

Oxygen-17 and sodium-23 nuclear magnetic resonance studies of myofibrillar protein interactions with water and electrolytes in relation to sorption isotherms

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxygen-17 and sodium-23 nuclear magnetic resonance studies of myofibrillar protein interactions with water and electrolytes in relation to sorption isothermsTheodore S. Lioutas, Ion C. Baianu, Peter J. Bechtel, and Marvin P. SteinbergCite this: J. Agric. Food Chem. 1988, 36, 3, 437–444Publication Date (Print):May 1, 1988Publication History Published online1 May 2002Published inissue 1 May 1988https://doi.org/10.1021/jf00081a009RIGHTS & PERMISSIONSArticle Views38Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (999 KB) Get e-Alerts Get e-Alerts

Sodium ion exchange on the 1,4,7,10,13,16-hexaoxaoctadecanesodium(I) cation ([Na.18C6]+) in several solvents. A sodium-23 nuclear magnetic resonance study

23 Na N.m.r. studies of Na+ exchange on the 1,4,7,10,13,16-hexaoxaoctadecanesodium(I) cation ([Na.18C6]+) in acetone, methanol and pyridine yield the respective decomplexation rate constants 10–2kd(265 K)= 606 ± 88, 42 ± 2 and 7.16 ± 0.30 s–1; and the corresponding activation parameters ΔH‡= 36.7 ± 0.7, 53.6 ± 0.8 and 50.5 ± 1.2 kJ mol–1; and ΔS‡=–14.0 ± 3.2, 27.8 ± 2.9, and 1.4 ± 4.2 J K–1 mol–1. These data are discussed in conjunction with data obtained from other n.m.r. and ultrasonic relaxation studies, and mechanistic aspects of the complexation of Na+ by 18C6 are considered.

Complexation of sodium ion by the cryptand 4,7,13-trioxa-1,10-diazabicyclo[8.5.5]eicosane (C21C5) in a range of solvents. A sodium-23 nuclear magnetic resonance kinetic study

Etude de l'echange de Na + entre l'etat solvate et le cryptate [Nc. C21C 5 ] + , dans des solvants organiques. Constantes de vitesse de formation

Coil design for short echo time sodium-23 nuclear magnetic resonance imaging

The application of NMR imaging techniques to the in vivo distribution of sodium has demonstrated that certain pathological conditions in tissue, especially infarction, can lead to a dramatic increase in the apparent sodium signal (1, 2). Most of these experiments have been done with spin-echo techniques with echo times typically in the range of 10 to 20 milliseconds. These results have also demonstrated that the effective T2 of the in vivo signal ranges from 3 to 30 milliseconds (2) which is shorter than that of purely aqueous solution. This indicates that improvements in signal-tonoise ratio should be possible with shorter echo times. The reason for the shorter relaxation times in vivo has recently been elucidated. In 1970, Hubbard showed the theoretical existence of a biexponential T2 relaxation in spin-; nuclei (3). Subsequently, Bull (4) extended the theory to compute correlation times from the different relaxation times. Chang and Woessner (5) demonstrated the presence of the biexponential transverse relaxation in rat leg muscle. One component is very fast and the other somewhat longer (Tz~ = 1.5 ms and Tzs = 15 ms at 26.5 MHz). The so-called “invisible” component, comprising 60% of the signal, decays with the short T2 and 40% decays with the longer T2. These results are significant because the majority of the intracellular component of the sodium signal will have disappeared before one has a chance to measure it. The intracellular component of the sodium signal could be of interest, since the correlation times derived from the relaxation data describe the duration and extent of interaction between sodium ions and intracellular macromolecules (5). Thus, it may be desirable to measure the T2’s in a variety of tissues, which can be done in vivo using imaging. There are two technical factors which limit the echo times which can be achieved in sodium imaging. One of these is the switching time of the gradient fields; this is limited by the inductive time constant of the gradient coils and the level of gradient power available and is not the subject of this communication. A second limit is the time necessary to develop the required 90 or 180” radiofrequency pulses. Both of these factors are exacerbated by the fact that the gyromagnetic ratio of sodium is only about one-fourth that of protons, so that the magnetic field strengths required are therefore four times stronger for sodium than for protons.