title: Preparative separation of isomeric sulfophthalic acids by conventional and pH-zone-refining counter-current chromatography.
abstract: Two modes of high-speed counter-current chromatography (HSCCC) were applied to separate 3- and 4-sulfophthalic acid from a mixture. Conventional HSCCC was useful for the separation of up to several hundred milligram quantities of these positional isomers, while pH-zone-refining CCC was implemented successfully to separations at the multigram level. The conventional HSCCC separations were performed with a standard J-type HSCCC system that has a superior resolution but a lower level of retention of the stationary phase of the biphasic solvent system used (acidified n-butanol-water). The pH-zone-refining CCC separations were performed with an X-type HSCCC system (a cross-axis system) that has a higher capability for retention of the stationary phase. The purified positional isomers (over 99% pure as determined by HPLC) were characterized by 1H NMR and negative ion electrospray ionization mass spectrometry.
authors.affiliation: aweisz@cfsan.fda.gov
authors.forename: Adrian
authors.initials: A
authors.lastname: Weisz
authors.forename: Eugene P
authors.initials: EP
authors.lastname: Mazzola
authors.forename: Constance M
authors.initials: CM
authors.lastname: Murphy
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D010795:Phthalic Acids / Q000302:isolation & purification*
chemical_list: D010795:Phthalic Acids