Retention time prediction

Apart from one compound (II), the lignin model compounds that had free phenolic groups eluted at close to the retention times predicted by the calibration curve from the polymer standards and not from the derive tized model compounds. This could simply be a result of the underivatized models having a similar variation in hydrodynamic volume with molecular weight as the polymer standards. However, it is to be expected that solvation of the underivatized model compounds should occur with THF as solvent (10), with hydrogen bonding of one THF molecule to each under-... 

The retention time predicted for a given peptide is equal to the sum of the retention coefficients for each residue and the terminal group, plus t0 (the elution time for an unretained compound) and ts (the difference between the observed ts and the calculated tr for a standard peptide). The retention times predicted for peptides with more than 20 residues are poorly correlated with experimental data, because the retention coefficients do not take steric factors into account. Moreover, the peptides may be denatured through the action of the solvents. 

Spicer, V. et al. Sequence-specific retention calculator a family of peptide retention time prediction algorithms in reversed-phase HPLC applicability to various chromatographic conditions and columns. Anal. Chem. 2007, 79, 8762-8768. 

The simplest and the most widely used forms of retention time prediction for analytical scale HPLC are based on the empirical linear dependence of the logarithm of the retention factor on the eluent composition. 

The physicochemical approach to retention time prediction has the advantage of accounting for the pH of the system by explicitly calculating p/C values... 

No structure-based system of retention time prediction to date has explicitly addressed the issue of the pH changes that result from the inclusion of organic modihers to the aqueous portion of the mobile phase and the resulting effects on both mobile-phase pH and analyte pKa shifts. Temperature... 

Advantages. Retention time prediction is a fast, effective way to get an idea of the approximate retention time that can be expected for a given compound under a given set of conditions. 

M. Palmblad, M. Ramstrom, C.G. Bailey, S.L. McCutchen-Maloney, J. Bergquist, L.C. Zeller, Protein identification by LC—A4S using retention time prediction, J. Chromatogr. B, 803 (2004) 131. 

A pharmacokinetic comparison of both product generations, and their formulation buffers was conducted in partially heparinized Sprague-Dawley rats using a monoclonal antibody capture/activity assay. The two rFVIII concentrates exhibited a high degree of similarity in half-life, area under the curve (AUC), clearance rate, and mean retention time, predicting biological activity of rAHF-PFM in humans similar to that of rAHF. 

The model of [22] or others described in [17] could be used in the calculation of GCxGC retention times or other parameters (e.g., RI values) for both and columns. However, at the time of writing this chapter, these procedures have not yet been applied in GCxGC. A publication on GCxGC retention time prediction [23] uses the previously mentioned CODESSA program package and experimental retention times obtained from the column in GCxGC, but the data are not included in the calculation. 

The above results indicated that electrostatic energy values strengthened the correlation. Therefore, the sum of MIHB and MIES used to study the contribution to the retention time prediction is ... 

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