QSRR study for gas and liquid chromatographic retention indices of polyhalogenated biphenyls using two 2D descriptors

Gas chromatographic and liquid chromatographic retention indices of polyhalogenated biphenyl compounds are successfully modeled by using two 2D descriptors of recently introduced MEDV-13 and atom-type E-state indices derived directly from the molecular structure. A five-variable regression equation was generated for the GC retention indices of 54 PHBs with the correlation coefficient (R) and relative standard deviation being 0.9921 and 2.4%. Also, a five-variable regression equation was generated for the LC retention indices of 56 PHBs with the correlation coefficient (R) and relative standard deviation of 0.9831 and 8.0%. The selected indices have been meaningful by using a molecular fragment analysis tool. Additionally, the leave-one-out cross-validation method demonstrates that the obtained models are statistically significant and reliable.