A One-Dimensional U-Net-Based Calibration-Transfer Method for Low-Field Nuclear Magnetic Resonance Signals

Abstract

The reconstruction of the statistical analysis model of an instrument is a time-consuming and expensive process. Herein, the feasibility of spectral model calibration-transfer application to the same type of low-field nuclear magnetic resonance (LF-NMR) instrument was investigated using a one-dimensional U-net (1D U-net). Unlike conventional calibration-transfer algorithms such as direct standardization (DS), the 1D U-net network can reduce the error between the master and slave instruments through iterative cycles. The calibration-transfer ability was verified; three experiments that entailed the use of edible oil and copper sulfate (CuSO 4 ) samples were implemented. The analysis of the spectral responses and feature analysis of the edible oil samples revealed that the signal of the slave instrument calibrated using the 1D U-net most resembled the signal of the master instrument, and its relative residual value was reduced to 0.0045. Further analysis of the CuSO 4 concentration prediction showed that on the support vector regression (SVR) model constructed using the master instrument, the signal of the slave instrument calibrated by the 1D U-net was more similar to the response of the master instrument, and its root mean square error (RMSE) was only 0.01606 mmol/L. Thus, 1D U-net is a viable candidate for calibration-transfer applications to LF-NMR instruments.

Is the Calibration Transfer of Multivariate Calibration Models between High- and Low-Field NMR Instruments Possible? A Case Study of Lignin Molecular Weight

“…The most recent one is less relevant for this study since it is based on time-domain NMR. 6 The second study successfully performed transfers of partial least squares (PLS) regressions between 43, 60, and 80 MHz benchtop NMR devices. 7 This study demonstrated the potential of calibration transfer between low-field 1 H NMR.…”

“…Several studies have been devoted to calibration transfer between high-field NMR instruments. , However, until now, there have only been two studies investigating the feasibility of calibration transfer between low-field 1 H NMR. The most recent one is less relevant for this study since it is based on time-domain NMR . The second study successfully performed transfers of partial least squares (PLS) regressions between 43, 60, and 80 MHz benchtop NMR devices .…”

Parameter Visualization of Benchtop Nuclear Magnetic Resonance Spectra toward Food Process Monitoring

“…Various methods were proposed for spectral data transfer from low-field to high-field NMR, which include direct standardization and piecewise direct standardization [42,43]. The possibility of NMR data transfer from a low field to a high field has also been investigated in time-domain NMR [44]. In addition, calibration transfer of low-field proton NMR ( 1 H-NMR) spectra using partial least squares regression in 40-, 60-, and 80-MHz benchtop NMR has been investigated [45].…”