Practical guide for selection of ¹H qNMR acquisition and processing parameters confirmed by automated spectra evaluation

Abstract

In our recent paper, a new technique for automated spectra integration and quality control of the acquired results in qNMR was developed and validated (Monakhova & Diehl, Magn. Res. Chem. 2017, doi: 10.1002/mrc.4591). The present study is focused on the influence of acquisition and postacquisition parameters on the developed automated routine in particular, and on the quantitative NMR (qNMR) results in general, which has not been undertaken previously in a systematic and automated manner. Results are presented for a number of model mixtures and authentic pharmaceutical products measured on 500- and 600-MHz NMR spectrometers. The influence of the most important acquisition (spectral width, transmitter [frequency] offset, number of scans, and time domain) and processing (size of real spectrum, deconvolution, Gaussian window multiplication, and line broadening) parameters for qNMR was automatically investigated. Moderate modification of the majority of the investigated parameters from default instrument settings within evaluated ranges does not significantly affect the trueness and precision of the qNMR. Lite Gaussian window multiplication resulted in accuracy improvement of the qNMR output and is recommended for routine measurements. In general, given that the acquisition and processing parameters were selected based on the presented guidelines, automated qNMR analysis can be employed for reproducible high-precision concentration measurements in practice.

Monitoring daily routine performance in quantitative NMR (qNMR) spectroscopy: Is the system suitability test necessary?

“…Previously, the script was developed to automate qNMR analysis including preprocessing and integration steps. [12,13] In the current study based on this experience, a system to support automated assessment of NMR performance characteristics with their evaluation based on univariate and multivariate statistics is described. From the list of available individual tests to perform such measurements on a liquid state NMR spectrometer, two standard solutions sealed in the NMR tube and distributed by the vendor were selected.…”

“…Previously, the script was developed to automate qNMR analysis including preprocessing and integration steps . In the current study based on this experience, a system to support automated assessment of NMR performance characteristics with their evaluation based on univariate and multivariate statistics is described.…”

Quality Control of Therapeutic Peptides by 1H NMR HiFSA Sequencing

“…33 An NMR method is then designed with appropriate acquisition parameters utilizing quantitative NMR (qHNMR) guidelines. 33–35 Sample preparation and acquisition should be repeated to achieve the intended reproducibility.…”

Quantitative Assessment of the Absolute Purity of Thiopeptcin Reference Standard by 1H-NMR

“…Futhermore, it can increase the accuracy and reproducibility, and be free of systematic and user-specific errors. 24,25 Although the qNMR method spends much time to do the data processing, it still uses less time comparing with the mass balance approach. Also, with development of the new technique, qNMR method is still the preferred choice for the absolute purity of innovative drugs reference standards.…”