Cyclodextrin sulfobutyl ether is sulfonated derivative of cyclodextrin. The degree of sulfobutylation varies, and the compound is a mixture of several components. All compounds are very polar and acidic in nature, and are not retained by traditional reversed-phase chromatography. Separation was achieved on an Obelisc N column in anion-exchange mode. Hydrophobic naphthalene was used a a reference standard. Cyclodextrin was monitored by ELSD.