Applied in Solid Phase Extraction for So

This study explores the retention mechanisms applicable in solid phase extraction (SPE) for polar compounds of pharmaceutical interest, specifically captopril, atenolol, and metformin. The primary objective was to compare the retention capabilities under reversed-phase and ion-pair mechanisms using octadecylsilica-based adsorbents in commercial cartridges with two different sorbent loadings. Methodologically, breakthrough parameters were measured, including hold-up, breakthrough, and retention volumes, derived from experimental data acquired through the percolation of C18 cartridges with stock solutions of each compound. The experimental curves representing these retention behaviors were fitted using Boltzmann's function, allowing for the calculation of significant breakthrough parameters from the regression analysis. Results showed variations in retention volumes and breakthrough characteristics based on the cartridge type and the polarity of the compounds, highlighting the complexity of the interactions at play. The findings suggest that optimizing the sorbent selection and understanding the solute-sorbent interactions are crucial for enhancing the efficiency of SPE methods tailored for polar pharmaceuticals.