METHOD AND DEVICE FOR HIGH-SENSITIVITY DETECTION

PURPOSE:To perform replacement and positioning alignment of a capillary readily by aligning the position of a circular reflecting mirror once. CONSTITUTION:A cylindrical flow cell 5 is provided at the center of a cylindrical or spherical reflecting mirror 3 having an incident window 1 and an emitting window 2. The quartz flow cell 5, wherein a film layer around a part of a capillary 10 is removed, is provided in a through hole 11 provided at the center of the mirror with a screw 12 having the ferrule in the outer surface reflecting mirror 3 of the quartz sphere, wherein the incident window 1 and the emitting window 2 that are made to face approximately are provided. A photodetector 9 is arranged on the side of the emitting window 2. The focal point of incident light 6, which enters through the incident window 1, is focused in the vicinity of the center of the reflecting mirror 3. The light is transmitted through the flow cell. The reflection and the tansmittance are repeated many times in the facing reflecting mirror 3. Then, the transmitted light 7 is emitted from the emitting window 2 and cast into the photodetector 9.