title: Development of a large-volume, membrane-based injection system for gradient elution micro-liquid chromatography.
abstract: A membrane unit which can be used to inject a large volume of sample solution was developed to facilitate reproducible and accurate gradient elution in micro-high-performance liquid chromatography (micro-HPLC). Since the membrane unit has a very low void volume, it facilitates the effective concentration of analytes in large sample volumes. Gradient elution micro-HPLC with the membrane unit allowed the efficient separation of n-alkyl benzoates, used as test samples, in a short time without marked gradient delay. In this study, the membrane unit could be loaded with up to 50 microg of n-hexyl benzoate, and more than 500 microL of sample solution could be applied. In about 50 chromatographic runs, the relative standard deviation (RSD) of the relative retention time of n-hexyl benzoate with respect to methyl benzoate was 0.530%.
authors.affiliation: Analytical Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan. k-murata@hhc.eisai.co.jp
authors.forename: Kaoru
authors.initials: K
authors.lastname: Murata
authors.forename: Nariyasu
authors.initials: N
authors.lastname: Mano
authors.forename: Naoki
authors.initials: N
authors.lastname: Asakawa
mesh_terms: D001565:Benzoates / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008567:Membranes, Artificial; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry
chemical_list: D001565:Benzoates; D008567:Membranes, Artificial; D014867:Water