QSRR Study on Flavor Compounds of Diverse Structures on Different Columns with the Help of New Chemometric Methods

Abstract

A quantitative structure–retention relationship study was performed for 286 flavor compounds with highly structural diversity on different stationary phases of different polarities. Firstly, the structure–retention relationship was statistically explored using constitutional, topological, molecular properties, charge descriptors and quantum chemical descriptors. Some recently developed chemometric methods, such as the ones for robust analysis and variable selection were firstly employed to predict accurately the gas chromatographic retention indices. The stability and validity of models have been tested by internal and external validation, and good robustness and predictive ability were obtained. The resulting QSRR models were well correlated, with the square of correlation coefficient for cross validation, Q 2, values of 0.9847, 0.9838, 0.9745 and 0.9646 on stationary phase DB5, OV101, OV17 and C20M, respectively. The molecular properties known to be relevant for GC retention index, such as molecular size, branching, electron density distribution and hydrogen bond effect were well covered by generated descriptors. The descriptors used in models on four stationary phases were compared, and some reasonable explanations about gas chromatographic retention mechanism were obtained. The developed model may be useful for the prediction of flavor compounds while experimental data are unavailable.