Erroneous values greatly affect the accuracy of the prediction, especially when the database is small, as seen in the polar phase example. The predicted indices for the mid-polar stationary phase showed good convergence with the experimental data. It is also worth noting that this phase showed the best separation ability compared to the polar and non-polar phases, and these phases should be used to analyze UDMH transformation products. The obtained data will allow to enrich the databases, which will subsequently improve the accuracy of GC RI prediction. Our results can be used in non-target screening to adjust the identification of compounds of emerging concerns that are not available as reference standards. This approach would provide, by establishing the right structure, a more accurate assessment of the environmental impact of UDMH and its transformation products.