Broadening, deconvolution correction

Figure 14. Deconvolution correction for instrumental broadening—simulation. Profile b unfolded from Profile a to give Profile c.

Gugliotta, L. M., Vega, J. R., and Meira, G. R., Instrumental broadening correction in size exclusion chromatography. Comparison of several deconvolution techniques, /. Liq. Chromatogr., 13,1671, 1990. 

The two most common methods used to correct resolved peak profiles for the broadening imposed by the finite width of the X-ray beam in the diffractometer, are due to Jones (15) and Stokes (16). Both are essentially unfolding or deconvolution methods, but the Jones method defines specific functions for both the uncorrected and the instrumental broadening profile. If the uncorrected profile is Gaussian, then... 

Since the model given by Eq. 6.133 concerns only the stationary phase process, the mobile phase dispersion and extra column broadening effects have to be corrected for via the deconvolution of the whole chromatogram with the peak of the imretained marker that contains the necessary information regarding these contributions to the band profiles. The resulting net chromatogram carries the contribution of the stationary phase processes only. 

The correction for instrumental broadening is known as deconvolution. Deconvolution procedures that can be used with dispersive spectrometers have been described (see for instance [51]. In this book, unless otherwise specified, the FWHMs indicated are considered to be corrected for instrumental broadening. 

The BE in APS is obtained directly from the recorder plots by applying the correction for the work function of the thermionic electron soiuce. To avoid the imcertainty introduced due to this correction in BE measiuements, Fukuda et al. [34] have used a field-emission soiurce. In earlier measurements in APS, the BE was determined in a simple way by the intersection of the extrapolated projection of the bac ound and positive going low energy slope of the peak. Since the APS yield is proportional to the self-convolution of the density of the final electron states broadened by the finite lifetime of the core hole and other effects stated earlier, precise knowledge about BE can be obtained by using deconvolution techniques. Successful deconvolution techniques have been developed by Fukuda et al. [34], Dose et al. [35,36], and Schulz et al. [37]. 

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