CALCULATION OF RETENTION INDEXES AND PEAK WIDTHS IN TEMPERATURE-PROGRAMMED GAS-LIQUID-CHROMATOGRAPHY

Isothermal chromatographic measurements lead directly to DELTAH(V)O an d A (entropy term) of solutes, and three constants of an empirical rel ationship between peak width and column temperature. From the thermody namic parameters DELTAH(V)O and A retention temperatures have been com puted by means of a theoretical model including temperature dependence of carrier gas viscosity, and subsequently retention times; programme d retention indices have been determined by linear and polynomial inte rpolations. By substituting the value of the calculated retention temp erature in the above-mentioned relationship, peak width at half-height for a linear temperature may be estimated. Predicted retentions corre late with observed data, with a P-value less-than-or-equal-to 0.01; si mulation accuracy is generally 6-10 % for peak widths. Retention indic es of some organochlorine species, separated on an OV-101 capillary co lumn, may differ by as much as 26 units depending on the method of cal culation. Polynomial-calculated indices are more consistent with the r etention index scheme, and have smaller standard deviations and better constancy at different heating rates.