Open Notebook NMR – Henry's improved protocol

When we first started this (nearly a month ago). Henry suggested a protocol for calculating the chemical shifts. Nick tooled up for this and had to overcome several technical problems on job submission, etc. (A typical example – the order of arguments in a Condor machine filter seems to matter – anyway shuffling them fixed the problem. This took at least a week out of our elapsed lives. This is not really chemistry, but it’s part of eScience, just as analysing solvents from different suppliers is part of chemistry.). Here’s the first graph Nick got (you’ve seen it already):
nmr1.PNG
During this period Henry improved his protocol, but we continued to use the old one until the jobs finished. Then we re-ran them all with the new one (details will come later):
nmr2.PNG
you can see there is a small but significant improvement. We believe that when the data errors are filtered out the improvement will be much clearer and more obviously valuable.
We’ll let Henry tell you what he’s done when it’s relevant.
WE ACKNOWLEDGE JOE TOWNSEND’S PLOTTING SOFTWARE WHICH WHEN DISPLAYED AS SVG (LATER THIS WEEK) ALLOWS EXCITING THINGS.

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3 Responses to Open Notebook NMR – Henry's improved protocol

  1. Peter…I have to admit I see hardly any difference at all in the plots except in the outliers (and only subtle then). What are the regression stats for the plots. Also, plots of the nature shown at the following page http://www.acdlabs.com/products/spec_lab/predict_nmr/chemnmr/ are generally of value when comparing improvements in algorithm performance. it’s a good way to compare your own improvements in algorithm (or Henry’s) as well as between algorithms

  2. pm286 says:

    (1) The differences do not account for the major variance, but they are significant and tighten up the plots – changes range between + and – 5 ppm. It will be clearer when the major causes of outliers are removed.
    P.

  3. pm286 says:

    (3) Thanks for the reference http://www.acdlabs.com/products/spec_lab/predict_nmr/chemnmr/ I will comment on this later.

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