title: Determination of some aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography with conductimetric detection on a weakly acidic cation-exchange resin column.
abstract: The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences.
authors.affiliation: Department of Chemistry and Biotechnology, School of Engineering, Kinki University, 1 Umenobe, Takaya, Higashi-Hiroshima 739-2116, Japan. itok@hiro.kindai.ac.jp
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ito
authors.forename: Yohichi
authors.initials: Y
authors.lastname: Takayama
authors.forename: Mikaru
authors.initials: M
authors.lastname: Ikedo
authors.forename: Masanobu
authors.initials: M
authors.lastname: Mori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taoda
authors.forename: Qun
authors.initials: Q
authors.lastname: Xu
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Hu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sunahara
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Hayashi
authors.forename: Shinji
authors.initials: S
authors.lastname: Sato
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hirokawa
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000143:Acids; D000693:Anaerobiosis; D002264:Carboxylic Acids / Q000032:analysis*; D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D010316:Particle Size
chemical_list: D000143:Acids; D002264:Carboxylic Acids; D002411:Cation Exchange Resins