title: Split flow and bypass flow systems for monolithic capillary columns in liquid chromatography.
abstract: Split flow and bypass flow systems were assembled using Nano Y Connectors with low dead volume commercially available for capillary liquid chromatography (LC). The split ratio could be controlled by changing the dimension of restriction tubing and applied back pressure to the restriction tubing. The split flow system allowed us to use valve injectors and pumps commercially available for capillary LC. The reproducibility of the present split flow system was acceptable. The relative standard deviation for six successive measurements was 0.4% for the retention time, whereas that for the peak height and peak area was 1-3% depending on the analytes. The bypass flow system uses two Nano Y Connectors, where the eluent split at the first Nano Y Connector, which is located in the inlet of the separation column, is merged again into the effluent from the column at the second Nano Y Connector. The bypass flow system could avoid on-column detection and allowed us to use flow cells, leading to an approximate three times improvement in signal-to-noise. The present flow systems were evaluated by using aromatic hydrocarbons and alkylbenzenes as test analytes.
authors.affiliation: Department of Chemistry, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. takeuchi@apchem.gifu-u.ac.jp
authors.forename: Toyohide
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tatsumi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Masuoka
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Hirose
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Uzu
authors.forename: Ji-Ye
authors.initials: JY
authors.lastname: Jin
authors.forename: Chuzo
authors.initials: C
authors.lastname: Fujimoto
authors.forename: Kazutoku
authors.initials: K
authors.lastname: Ohta
authors.forename: Kwang-Pill
authors.initials: KP
authors.lastname: Lee
authors.forename: Je-Jeong
authors.initials: JJ
authors.lastname: Ryoo
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
mesh_terms: D002853:Chromatography, Liquid / Q000295:instrumentation*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet