[Analysis of aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography].
The analysis of seven aliphatic carboxylic acids (formic, acetic, propionic, iso-butyric, n-butyric, iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents (benzoic acid, perfluorobutyric acid (PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet (UV) detection. The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column (TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column (TSKgel Super IC-A/C). Good separation was performed on the TSKgel SCX in shorter retention times. For the TSKgel Super IC-A/C, peak shape of the acids was sharp and symmetrical in spite of longer retention times. In addition, the mutual separation of the acids was good except for iso- and n-butyric acids. The better separation and good detection was achieved by using the two columns (TSKgel SCX and TSKgel Super IC-A/C connected in series), lower concentrations of PFBA and sulfuric acid as eluents, non-suppressed conductivity detection and UV detection at 210 nm. This analysis was applied to anaerobic digestion process waters. The chromatograms with conductivity detection were relatively simpler compared with those of UV detection. The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.
Department of Biotechnology and Chemistry, Faculty of Engineering, Kinki University, Higashi-Hiroshima 739-2116, Japan. itok@hiro.kindai.ac.jp
Kazuaki
K
Ito
Jun
J
Sakamoto
Kazuya
K
Nagaoka
Yohichi
Y
Takayama
Takashi
T
Kanahori
Hiroshi
H
Sunahara
Tsuneo
T
Hayashi
Shinji
S
Sato
Takeshi
T
Hirokawa
Kazuhiko
K
Tanaka
D000693:Anaerobiosis; D002087:Butyrates / Q000032:analysis; D002264:Carboxylic Acids / Q000032:analysis*; D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange; D005227:Fatty Acids / Q000032:analysis*; D005561:Formates / Q000032:analysis; D011422:Propionates / Q000032:analysis
D002087:Butyrates; D002264:Carboxylic Acids; D002411:Cation Exchange Resins; D005227:Fatty Acids; D005561:Formates; D011422:Propionates; C030544:formic acid; C029658:propionic acid