Patent ID: 6780325
Filing Date: 2004-08-24
Classification: G01N

Abstract:
A method for analyzing a trace amount of a component in a sample with improved detection sensitivity, which method comprises the steps of:providing a high performance liquid chromatographic apparatus having a flow velocity gradient of 250 microliters per minute or less, said apparatus comprising a solvent pump (P1), and injector (I), and a switching valve (V) connected in that order in a first line and a solvent pump (P2), a switching valve (V), a diffusion promoting device (DU), a separation column (C), and a detector (D) connected in that order in a second line, wherein said diffusion promoting device comprises a solvent inlet tube and a solvent outlet tube having at least (i) a solvent inlet tube and a solvent outlet tube with different inner diameters or (iii) a solvent outlet tube connected to a solvent inlet tube by a connecting part having a diameter that is larger than the diameters of the diameters of the solvent inlet and outlet tubes; trapping the target component in a component concentration column (M) by means of a mobile phase discharged from the solvent pump (P1); discharging a different mobile phase from the solvent pump (P2) by turning the switching valve; and eluting the target component from the separation column (C) through diffusion of the target component using the diffusion promoting device (DU).