Development and application of chromatographic gray model (II) - Establishment of nonlinear continuous gray model NLCGM(1,1) and prediction retentionbehavior of aromatic hydrocarbons

The deficiency of the traditional GM(1,1) model for solving the nonlinear p roblem is pointed out, and an improved model NLCGM(1,1) is proposed by mean s of gray theory. During establishing the model, the double fitting is intr oduced both to improve the accuracy of the prediction and to achieve the co ntinuous model. The model has been successfully applied to study the relati onship between the capacity factor (k') of 32 polycyclic and monocyclic aro matic hydrocarbons and the composition of mobile phase(phi) in high perform ance liquid-phase chromatography, and good results are obtained. In conclus ion, there are three advantages for NLCGM(1,1) model. (1) Capacity factor c an be predicted at any composition of mobile phase because the independent variable of the gray model can change continuously. (2) The precision of NL CGM(I,1) is higher than that of the traditional GM(1,1), (3) The traditiona l GM(1,1), is the special case of NLCGM(1,1), Therefore, the establishment of NLCGM(1,1) broadens the applied range of gray model.