CRAFT for Delta

JEOL is pleased to have released CRAFT (Complete Reduction to Amplitude-Frequency Table) for Delta V1.0 with Delta V5.3.0 software. Integration of CRAFT allows the JEOL NMR user to automatically and efficiently extract the best amplitudes and frequencies from NMR data.

On the NMR Support web site, the following resources are available for registered users:

What is CRAFT?

CRAFT Data Flow
CRAFT data flow. CRAFT directly converts FID into a table consisting of frequency and amplitude for each frequency component. CRAFT and Delta reconstruct the spectrum for visual inspection.

“Spectrum direct to Spreadsheet”

Pioneering work for direct time-domain analysis of NMR data was begun by Dr. Krish Krishnamurthy and first published in 2013. [1]. This work was extended to 2-dimensional NMR in 2016 [2]. CRAFT provides a direct spectrum to spreadsheet by utilizing Bayesian analysis of the time domain spectrum thereby bypassing many issues brought about by the Fourier transform to a visual frequency dimension. Direct analysis of time-domain completely bypasses the issues of baseline and phase. In addition, the concept of spectral overlap is redefined. Two peaks which are too close to effectively quantify by traditional integration are completely resolved sinusoids in the time domain with separate information of frequency, amplitude, phase, and decay rate available as numbers in a table.
The Fourier transform has been traditionally used to transform time domain data into a 2-dimensional space which is comfortable to look at and easy to understand. Ironically the goal is often to then do lots of post transformation analysis on the frequency spectrum for the purpose of putting the information into a table which is easy for a computer to understand. CRAFT uses the visual frequency domain simply as guidance to make easy for a human to choose what they wish to analyze. The output of CRAFT is a spreadsheet arising purely from the time domain data neatly tabulated as frequency and amplitude with phase and decay rate also available if desired. Again, for the purpose of comfort factor the resulting table is used to simulate a complete spectrum and the simulated FID and actual experimental FID are subtracted to provide a quick visual means to evaluate the quality of the analysis.
Figure 1. Expansion showing complete craft analysis of santonin in the Delta CRAFT Tool.
Figure 1. Expansion showing complete craft analysis of santonin in the Delta CRAFT Tool.
Figure 2. Expansion of the craft simulation and experimental result for santonin.
Figure 2. Expansion of the craft simulation and experimental result for santonin. Note how even the details of the 13C satellites can be easily captured and quantified.

Further Workflow Examples

Workflow of CRAFT

  • FID is converted into sub-FIDs via digital filtering.
  • A table is generated by use of the Bayesian analysis.
Workflow of CRAFT

Comparison of an exponentially decaying sinusoid in time domain and frequency domain

  • The Fourier transform of a decaying exponential function is a Lorentzian shaped line.
  • The amplitude of the exponentially decaying sinusoid corresponds to integrated area of the Lorentzian peak.
Comparison of an exponentially decaying sinusoid in time domain and frequency domain

References

  • CRAFT (complete reduction to amplitude frequency table) – robust and time-efficient Bayesian approach for quantitative mixture analysis by NMR. Krish Krishnamurthy – Magn. Reson. Chem. 24 October 2013.
  • Application of CRAFT in two-dimensional NMR data processing. Krish Krishnamurthy, Andrea M. Sefler, and David J. Russell. Magn Reson. Chem. 10 May 2016
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