Chromatographic behavior of small organic compounds in low-temperature high-performance liquid chromatography using liquid carbon dioxide as the mobile phase.
Low-temperature high-performance liquid chromatography, in which a loop injector, column, and detection cell were refrigerated at -35ºC, using liquid carbon dioxide as the mobile phase was developed. Small organic compounds (polyaromatic hydrocarbons, alkylbenzenes, and quinones) were separated by low-temperature high-performance liquid chromatography at temperatures from -35 to -5ºC. The combination of liquid carbon dioxide mobile phase with an octadecyl-silica (C18 ) column provided reversed phase mode separation, and a bare silica-gel column resulted in normal phase mode separation. In both the cases, nonlinear behavior at approximately -15ºC was found in the relationship between the temperature and the retention factors of the analytes (van't Hoff plots). In contrast to general trends in high-performance liquid chromatography, the decrease in temperature enhanced the separation efficiency of both the columns.
Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Japan.
Tomohiro
T
Motono
Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Japan.
Takashi
T
Nagai
Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Japan.
Shinya
S
Kitagawa
Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Japan.
Hajime
H
Ohtani
D000097:Acetonitriles / Q000737:chemistry; D000873:Anthracenes / Q000032:analysis; D000880:Anthraquinones / Q000032:analysis; D001555:Benzene Derivatives / Q000032:analysis; D002152:Calorimetry, Differential Scanning; D002245:Carbon Dioxide / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003080:Cold Temperature; D006586:Hexanes / Q000737:chemistry; D009281:Naphthalenes / Q000032:analysis; D009285:Naphthoquinones / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D011721:Pyrenes / Q000032:analysis; D011809:Quinones / Q000032:analysis; D012822:Silicon Dioxide / Q000737:chemistry
D000097:Acetonitriles; D000873:Anthracenes; D000880:Anthraquinones; D001555:Benzene Derivatives; D006586:Hexanes; D009281:Naphthalenes; D009285:Naphthoquinones; D009930:Organic Chemicals; D011721:Pyrenes; D011809:Quinones; C026679:octadecylsilica; C024268:n-propylbenzene; D002245:Carbon Dioxide; C031721:naphthalene; D012822:Silicon Dioxide; C030984:pyrene; C034020:anthracene; C004912:ethylbenzene; C032159:acetonitrile
Column efficiency; Liquid carbon dioxide; Low-temperature high-performance liquid chromatography; van't Hoff plots