Pure Gaussian Apodisation Reduces Integral Crosstalk Sensitivity in Quantitative NMR

Primary NMR data used during assessment of exponential and Gaussian apodisation for quantitative NMR measurements. Abstract: Exponential apodisation is routinely applied in quantitative NMR measurements to increase signal-to-noise (S/N) and integral precision, with a peak broadening effect. However, apodisation suitability is typically evaluated using S/N and peak broadening metrics and does not consider how apodisation alters peak area distribution. Here, we assess how exponential apodisation extends peak wings and relocates area away from the peak centre. This necessitates larger integral regions to account for the same area, increasing the potential for peak overlap and introducing variability in accuracy. As an alternative, we show that a pure Gaussian apodisation can deliver comparable S/N improvements to the common exponential apodisation when tuned to a matched broadening criterion, reducing overlap of peak wings and improving robustness of finite-window integration. As a result, the narrower line width prior to apodisation can be used to guide appropriate integral region choice. Overall, a pure Gaussian apodisation is demonstrated to be a robust alternative to exponential apodisation, especially in conjunction with complex 1D NMR spectra.