The correlation between molecular structure parameters of O‐ethyl N‐isopropyl phosphoro(thioureido) thioates and their retention data in RP‐HPLC

A retention prediction system (RPS) of seven O-ethyl N-isopropyl phosphoro(thioureido)-thioates in reversed phase HPLC was investigated. The system is based on the solvent selectivity triangle concept. Three molecular structure parameters (hydrophobicity II, substituent length L, and substituent maximum with B5) were used to describe the quantitative structure-retention relationships. With these quantitative relationships, the retention behaviours of other eight homologs for different mobile phase composition were predicted. The predicted values were consistent with the measured values within relative error of 10%, which means that it is possible to apply the reported method to predict retention values for qualitative purposes for different mobile phase compositions.