Ion Pairing Questions

1. When analyzing a drug X (strongly basic) and preservatives B (neutral), and C (strongly acidic), what would be the advantage of using IP-HPLC over regular RP-HPLC?

2. When using an ion-pair–HPLC to analyze a basic sample and the pH is deceased. What would be the effect in the retention of the sample and why?

3. What are 3 advantages of ion-pair-HPLC?

4. What condition are need it during reversed Phase Chromatography to increase retention of a compound that requires a mobile phase with pH>8 to improve retention (without trying the addition of IPC-reagent)?