Why does my spectra seem to be shifted by approximately 0.01ppm after processing and calibration? OR When I use TSP as a CSI, why is the TSP peak not at 0 ppm?
12 March 2017 Comments Off on Why does my spectra seem to be shifted by approximately 0.01ppm after processing and calibration? OR When I use TSP as a CSI, why is the TSP peak not at 0 ppm? FAQ - Processing Spectra
The Chenomx Compound Library is based on the characteristics of DSS, since its chemical shift does not change with pH; the chemical shift of TSP does change with pH. When you select TSP as a CSI, your spectra are rereferenced as if they had been acquired using DSS to allow accurate comparison with the compound library.
This results in your spectra being shifted by about 0.01ppm compared to setting the TSP signal to 0 ppm. This may appear odd if you are used to referencing to TSP but it does allow you to accurately calibrate your spectra with TSP and still use our library compounds.
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