VariPure IPE is a polymer supported quaternary amine resin with a bicarbonate counter ion. It is designed for removing acidic ion-pair reagents, such as trifluoracetic acid (TFA), formic acid or acetic acid. It is a high performance and economical acid removal material conveniently supplied as pre-packed SPE type devices. The particle size, capacity and device geometry are matched to provide sufficient residence time to achieve effective ion-pair extraction under gravity flow. For acid labile peptides, removal of the ion-pairing agent prevents acid degradation of the peptide during post-HPLC work up, and increases the yield of purified product.