EFFECTS OF EXTRACOLUMN CONVOLUTION ON PREPARATIVE CHROMATOGRAPHIC PEAK SHAPES

The effects of extracolumn components on preparative (nonlinear) chromatographic peak shapes are Investigated by convoluting column inlet and outlet profiles of chromatographic simulations with Gaussian and exponential spreading functions. Broadening of the inlet profile serves mainly to retard the elution of the peaks. The chromatogram base-line width is very sensitive to small amounts of broadening at the outlet (detector). While linear chromatography is modeled by simple shift-invariant convolution, nonlinear chromatography requires the more complex shift-variant convolution model. This removes the property of variance additivity familiar in linear chromatography. The relative utilities of three measures of preparative chromatographic peak width are tested by using convoluted peak shapes. © 1990, American Chemical Society. All rights reserved.