title: Application of zirconium-modified silica gel as a stationary phase in the ion-exclusion chromatography of carboxylic acids. II. Separation of aliphatic carboxylic acids with pyromellitic acid as eluent and with suppressed conductimetric detection.
abstract: The application of zirconium-modified silica gels (Zr-Silica) as stationary phases for ion-exclusion chromatography with conductimetric detection (IEC-CD) for C1-C8 aliphatic carboxylic acids (formic, acetic, propionic, butyric, valeric, caproic, heptanoic and caprylic acids) was carried out using pyromellitic acid as the eluent. Zr-Silicas were prepared by the reaction of the silanol group on the surface of silica gel with zirconium tetrabutoxide [Zr(OCH2CH2CH2CH3)4] in ethanol solution. An ASRS-Ultra anion self-regenerating suppressor in the K+ form was used for the enhancement of conductimetric detector response of these aliphatic carboxylic acids. A Zr-Silica adsorbed on 10 mg zirconium g(-1) silica gel was the most suitable stationary phase in IEC-CD for the separation of these aliphatic carboxylic acids. Excellent simultaneous separation and highly sensitive detection for these aliphatic carboxylic acids were achieved in 25 min by IEC-CD with the Zr-Silica column (250x4.6 mm I.D.) and a 0.2 mM pyromellitic acid containing 0.15% heptanol as the eluent.
authors.affiliation: National Industrial Research Institute of Nagoya, Japan. kazuohta@nirin.go.jp
authors.forename: K
authors.initials: K
authors.lastname: Ohta
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D002264:Carboxylic Acids / Q000302:isolation & purification*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004563:Electrochemistry; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001565:Benzoates; D002264:Carboxylic Acids; D058428:Silica Gel; D012822:Silicon Dioxide; D015040:Zirconium; C012018:pyromellitic acid