The prediction for gas chromatographic retention index of disulfides on stationary phases of different polarity.

Quantitative structure-retention relationship (QSRR) models for the gas chromatographic (GC) Kaváts indices of disulfides on four different polarity stationary phase have been developed. Semi-empirical quantum chemical method (AM1) implemented in hyperchem 4.0 was employed to calculate a set of molecular descriptors of 50 disulfides. The four stationary phases in the research were: Apiezon M, OV-17, Triton X-305 and PEG-1000. By using multiple linear regression (MLR), we obtained four empirical functions with high correlation coefficient (R(1)=0.995, R(2)=0.994, R(3)=0.990, R(4)=0.976). At the same time, using Thin Plat Spline the Radial Basis Function neural networks models were obtained with root mean squared error (RMS) of training set (RMS(T1)=0.013351, RMS(T2)=0.012973, RMS(T3)=0.023228, RMS(T4)=0.020755) and RMS of validation set (RMS(V1)=0.007626, RMS(V2)=0.005897, RMS(V3)=0.005109, RMS(V4)=0.007377) and RMS of testing set (RMS(X1)=0.016676, RMS(X2)=0.016704, RMS(X3)=0.017162, RMS(X4)=0.014755). The results indicated that the QSRR models proposed were very satisfactory.