103
edits
Changes
From Pumping Station One
→Operation / Background
== Operation / Background ==
== Operation / Background ==
* Unless performing more elaborate techniques, NMR spectra are generally a squiggly line.
* Unless performing more elaborate techniques, NMR spectra are generally a squiggly line.
** Y-Axis is intensity. Simple enough. If you take the area underneath a peak and add it up (integrate), you can now say something about how much of something exists and begin to quantify it.
** Y-Axis is intensity. Simple enough. The taller a peak, the more of something there is. If you take the area underneath a peak and add it up (integrate it), you can now say something about how much of something exists and begin to quantify it.
** X-Axis has quirks:
** X-Axis has quirks:
*** It technically represents the amount the frequency of whatever is being analyzed is shifted from the signal from TMS (which is used for calibration and whose single peak is considered 0).
*** It technically represents the amount the frequency of whatever is being analyzed is shifted from the signal from TMS (which is used for calibration and whose single peak is considered to be at 0ppm).
*** Also, 0 starts from the right side. Higher frequencies are to the left 0 on the X-Axis (Historical Quirks)
*** Also, 0 starts from the right side. Higher frequencies are to the left 0 on the X-Axis (Historical Quirks)
*** Technically, we are measuring how many Hertz higher something is than where the signal for TMS is.
*** Technically, we are measuring how many Hertz higher something is than where the signal for TMS is.
*** In practice, we never refer to this in Hz because the amount of shift would depend on the strength of the NMR we have. Since it would be nice to sensibly compare data across different instruments, the amount of Hertz shift is divided by the frequency of the instrument. We call this value PPM.
*** In practice, we never refer to this in Hz because the amount of shift would depend on the strength of the NMR we have. Since it would be nice to sensibly compare data across different instruments, the amount of Hertz shift is divided by the frequency of the instrument. We call this value PPM. Do not confused the usages of "PPM" here for perhaps the more common use case in other techniques where one would be referring to concentration of a sample. In all cases, it stands for "Parts per million", but here it is important to remember ppm is the x-axis, which has more to do with what something is and not with how much there is.
= Software =
= Software =
