Calibration Transfer of Chemometric Models Based on Process Nuclear Magnetic Resonance Spectroscopy

Abstract

This paper establishes the protocol for calibration transfer of partial least-squares (PLS) regression models between process nuclear magnetic resonance (NMR) spectrometers. The ability to transfer calibration models between instruments allows the addition of new instruments and the upgrade of old instruments with little financial or manpower investment. It will also allow development of calibration for an on-line system on a lab system, which will require less manpower and no down time for the on-line measurements. This capability will result in great cost savings for a production facility where even a minor interruption in the plant operations would result in great loss of production and loss of income.

Transfer of multivariate regression models between high‐resolution NMR instruments: application to authenticity control of sunflower lecithin

“…Up to five transfer samples were required for instrumental transfer for model ternary systems between high‐resolution NMR instruments . Fourteen to 56 samples were necessary for the same tasks for time‐domain low‐resolution NMR spectrometers . In this study it was shown that a significant calibration transfer models of high‐resolution NMR data with quite low RMSEP values can be achieved with 10 to 12 standardization samples in real spectroscopic applications.…”

“…A limited number of studies dealt with NMR instrument standardization. Several calibration transfer methods were tested to maintain PLS regression models of simulated FIDs of 77 polymer samples between low‐resolution 20 MHz NMR spectrometers . In this study a set of instrumental variations in probe ring‐down, pulse length and temperature was manually modelled to predict high‐load melt index values.…”

“…Limited number of studies is available for other spectroscopic techniques. Standardization was applied to mass spectroscopic data for quantitative assessment of lysozyme in binary mixtures with glycogen, to UV‐VIS spectra for calculating the pH of Sala mango, to Raman spectral data of ternary sugar mixtures with different values of fluorescent background or to low‐ and high‐resolution NMR data of simple mixtures …”

“…[9,10] Moreover, small unintended variations are attributed to changes in operating condition and hardware maintenance (changes in chemical shifts, pulse length, magnetic susceptibility, and temperature fluctuations). [9,10] These differences in spectra lead to a mismatch in PLS calibration models developed on one instrument with another set of spectra taken on another instrument and as a consequence, the calibration model can become unreliable.…”

The vector of calibration ratios: A simple transfer method for mass spectra

“…In the field of calibration this is commonly referred to as standardization of instruments [25]. Standardization and calibration transfers have been applied to correct for instrument differences in near infrared spectroscopy [25][26][27], nuclear magnetic resonance spectroscopy [28,29] pyrolysis mass spectra [30,31] and gas sensor arrays [32]. Because of different noise patterns, standardization and calibration methods are transferable only to a limited degree between these techniques.…”