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Manual |
This pop-up panel will appear when the Make I(q) button is pressed in the main HPLC-SAXS module. If a baseline was established and subtracted, each produced dataset will be marked with "bs" to indicate that. Since a non-zero baseline is usually due to spurious signals, such as the accumulation of material on the capillary walls during a chromatographic separation, baseline back-addition should not be done, and therefore it's not allowed in non-expert mode operation. The baselines are only added to the sums of Gaussians to verify that the original I(q) vs. q frames have been correctly reconstructed (see below).
Three options are present in this panel:
The extra line reads I(t) contains S.D.'s of zeros. When computing I(q) S.D.'s: and then offers three options:
I0 standard experimental value (a.u.):. A normalization factor from a standard sample to be associated with the data can be also entered here. If this checkbox is checked, its value will be associated in each resulting I(q) vs. q curve (default: unchecked).
Finally, if a concentration chromatogram has also been processed a calculated concentration can be assigned to each of the resulting I(q) vs. q curves. This is done by entering an extinction coefficient (or a dn/dc) for each Gaussian. In addition, a partial specific volume (psv) value, needed for the computation of the <M>w, <M/L>w/z, and <M/A>w/z by Guinier analysis in the main US-SOMO SAS module, can be also entered here. The module will present as many fields as the Gaussians used to decomposed the data. If all the Gaussians represent a species with the same extinction coefficient (or dn/dc) and psv, the values need to be entered only once in the 1st Gaussian fields, and then they can be propagated to all the other fields by pressing the Duplicate Gaussian 1 values globally button. The concentration value will be used when the Normalize button in the main HPLC-SAXS module is pressed after dataset selection.
It is also possible to back-generate an I(q) vs. q set without using the Gaussian decomposition by pressing the Make I(q) without Gaussians button.
For normal operation, once all fields/checkboxes have been properly set, pressing Continue will return to the main HPLC-SAXS window and start the make I(q) process.
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Last modified on May 20, 2014.