Description General description The role of ion-pairing reagents as mobile phase additives is to ensure easy separation of ionic and highly polar substances on reversed phase HPLC columns. The purity of mobile phase additives is a crucial factor for their optimal operation. Sigma-Aldrich consists of a wide variety of tailor-made reagents for anionic (quaternary ammonium and phosphonium salts) and cationic (alkanesulfonates) separation. All mobile phase additives have been subject to thorough testing with a special focus on the requisites of modern reversed phase HPLC: Recommended products Discover LiChropur™ reagents ideal for HPLC or LC-MS analysis Legal Information LiChropur is a trademark of Merck KGaA, Darmstadt, Germany