²H SOLCOR: A novel tool for reducing volume variation as a source of error in external standard quantitative NMR

Abstract

Tube to tube volume difference presents a challenge in obtaining correct external standard quantitative NMR (esqNMR) results. Deuterium ( 2 H) NMR is easily observable, intrinsically quantitative, present in all samples, free of interfering signals, and insensitive to probe tune/match and sample saltiness. These properties make 2 H peak integral an ideal parameter in esqNMR for correcting volume differences between the reference standard and analyte. We demonstrate a novel and practical technique abbreviated as " 2 H SOLCOR" ( 2 H SOLvent CORrected), where the 2 H peak integral from the solvent is used as a universal internal standard to correct volume variations in NMR tubes, thereby improving accuracy and precision of esqNMR method. Herein, this simple yet effective technique is described, and practical considerations for successful implementation are presented. 2 H SOLCOR can be applied anywhere esqNMR is used, including where precious samples need to be accurately quantified for qualification as an authentic analytical standard.

The effect of tube quality on externally calibrated quantitative nuclear magnetic resonance analysis: How bad can it be?

“…The main limitation of this approach has been discussed in previous reports [10][11][12][13] in which deuterated solvents were used for either calibration or volume correction: Given the significant lot-to-lot variability in the degree of deuteration of NMR solvents, both the calibrant and the test sample solutions must be prepared with the same lot of diluent. Additional drawbacks associated with the use of residual DMSO-d 5 for volume correction are (a) its exceptionally long T 1 value and (b) the likelihood of signal overlap in the narrow 1 H chemical shift range.…”

“…Additional drawbacks associated with the use of residual DMSO-d 5 for volume correction are (a) its exceptionally long T 1 value and (b) the likelihood of signal overlap in the narrow 1 H chemical shift range. Both disadvantages can be avoided with the application of 2 H-based volume correction strategies [10][11][12] but at the expense of analyzing a second NMR dataset (collected using a different hardware path) for each tube containing either calibrant or test sample solution.…”

“…Recently, the use of deuterium ( 2 H) NMR measurements to correct for volume variations in externally calibrated qNMR methods has been demonstrated. [10][11][12] However, this approach requires the collection of one extra dataset per each test sample. In this report, we leverage the residual protonated solvent signal in the 1 H NMR spectra [13][14][15] to compensate for differences in tube volume without the need to acquire, process, and analyze additional datasets.…”

Competition of quantum effects inH2/D2sieving in narrow single-wall carbon nanotubes

“…The importance of hydrogen in chemical research and industry cannot be overestimated: from its use as reagent in synthetic chemistry and several industrial processes, to its potential application as a clean fuel for combustion batteries, the future of our society seems to be inevitably tied to being able to harness hydrogen's capabilities as efficiently as possible [1][2][3]. One particular aspect of such harnessing is the separation of hydrogen and deuterium, since the latter has very different applications in the areas of isotopological tracing [4], proton nuclear magnetic resonance spectroscopy [5,6], neutron scattering [7,8]. If chemical separation processes are extremely costly per se, using around 10-15% of the total amount of energy consumed worldwide [9], isotopological separation is comparatively the most expensive [10,11].…”

Competition of quantum effects in H$_2$ /D$_2$ sieving in carbon nanotubes

“…The importance of hydrogen in chemical research and industry cannot be overestimated: from its use as reagent in synthetic chemistry and several industrial processes, to its potential application as a clean fuel for combustion batteries, the future of our society seems to be inevitably tied to being able to harness hydrogen's capabilities as efficiently as possible [1][2][3] . One particular aspect of such harnessing is the separation of hydrogen and deuterium, since the latter has very different applications in the areas of isotopological tracing 4 , proton nuclear magnetic resonance spectroscopy 5,6 , neutron scattering 7,8 . If chemical separation processes are extremely costly per se, using around 10-15% of the total amount of energy consumed worldwide 9 , isotopological separation is comparatively the most expensive 10,11 .…”