Liquid chromatograph

#The present invention relates to a liquid chromatograph, and more particularly to a liquid chromatograph having a miniaturized analytical section for separation and detection of a small amount of sample.

#The present invention also relates to a sample introduction apparatus and method suitable for a microliquid chromatograph by using a capillary column as a separation column.

#The present invention is also concerned with a detector disposed in a liquid chromatograph for detecting ionic components contained in a liquid sample to be analyzed, and more particularly with a liquid chromatograph detector which is inexpensive and disposable.

#The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of preferred embodiments as illustrated in the accompanying drawings in which reference characters refer to the same parts through the various views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention: in which

#FIG. 1 is a schematic exploded view showing an analyzing section in accordance with one embodiment of the invention;

#FIG. 2 is a top plan view showing the analytical section chip used in the embodiment shown in FIG. 1;

#The present invention will now be described with reference to the accompanying drawings. FIG. 9 shows a concept or principle of the entire flow path or passage of a liquid chromatograph to which the present invention is applied. In FIG. 9, parts 22a, 22b and 22c of a sample introduction section 22 constituted by flow passages 22a, 22b, 22c, 22d and 22e, a capillary column 21a and a detector 23 are formed in a chip 20 including a substrate made of silicon or glass. A switching-over valve 50a for selectively introducing separation carrier liquid or solution 301 and sample 300 is connected to one end, on the flow path 22d side, of the two ends of the U-shaped sample introduction section 22. A switching valve 50b for selective connection to a relief pipe 26a and a blocking or closed pipe 126b is connected to the other end, on the flow path 22e side, of the sample introduction section 22. A control device 81 and an output device 80 such as data processor are connected to a detecting part or detector 23 which serves for detecting separated components or constituents. The sample 300 is injected into the flow path by a syringe or injector 90 through a sample introduction pipe 126c and an excessive part of the sample is discharged from the relief pipe 126a. The carrier solution 301 is fed under pressure by a feed pump 60, and is discharged from a drain 55 after having passed through a tube 126 and the paths or passages within the chip 20.

#As described later, a rotor having the chip and a frame member serve as the switching valves 50a and 50b.

#One embodiment of the invention will now be described with reference to FIGS. 1 to 8.