BAND SPREADING MODELING ANDCORRECTION IN SIZE EXCLUSION CHROMATOGRAPHY NEW METHODS FOR BAND SPREADING PART II CORRECTION

• Published in: Chemical engineering communications 1987-01, Vol.49 (4-6), p.369-389
• Main Authors: COSTA, M. R. N., SCHWEICH, D., XIONG-WEI, HE, VILLERMAUX, J.
• Format: Article
• Language: English
• Subjects: Band spreading; Chromatography; Modeling; Size exclusion
• ISSN: 0098-6445; 1563-5201
• DOI: 10.1080/00986448708911812

The evaluation of the band spreading corrected chromatogram (the "ideal" chromatogram) from the observed one knowing the shape of single component chromatograms (described by the dispersion function) requires the solution of a Fredholm's integral equation of the first kind (Tung's equation), a mathematically ill-posed problem if details of the unknown chromatogram are sought at a scale narrower than that of single component chromatograms Most often, chromatogram deformation by instrumental spreading is not too severe and a correction method can be implemented which is based on a Taylor's series expansion. Such a method is proposed in the present paper. The correction is expressed as a function of the derivatives of the observed chromatogram and of the moments of the dispersion function, with an appropriate truncation. The derivatives are calculated from a polynomial approximation of the observed chromatogram which is fitted at each point. Numerical simulations show that the method withstands the problems caused by noisy data and can be applied to any shape for the dispersion function, not necessarily translation-invariant. The Taylor's series method can also be generalized to encompass the analysis of oligomers. Its simplicity and flexibility make it a candidate for widespread use in current analytical practice.