A new accurate quadratic equation model for isothermal gas chromatography and its comparison with the linear model

摘要

The gas holdup time (t _M) is a dominant parameter in gas chromatographic retention models. The difference equation (DE) model proposed by Wu et al. (J. Chromatogr. A 2012, http://dx.doi.org/10.1016/j.chroma.2012.07.077) excluded t _M. In the present paper, we propose that the relationship between the adjusted retention time t'RZ and carbon number z of n-alkanes follows a quadratic equation (QE) when an accurate t _M is obtained. This QE model is the same as or better than the DE model for an accurate expression of the retention behavior of n-alkanes and model applications. The QE model covers a larger range of n-alkanes with better curve fittings than the linear model. The accuracy of the QE model was approximately 2-6 times better than the DE model and 18-540 times better than the LE model. Standard deviations of the QE model were approximately 2-3 times smaller than those of the DE model.