Abstract: The fluorescence detector includes: a flow cell provided on a flow passage for flowing a sample; a sample temperature control block for keeping the flow cell and the flow passage located on the sample inlet side of the flow cell at a constant temperature; an excitation optical system; a fluorescence optical system having a photodetector and used for guiding fluorescence emitted from a sample flowing through the flow cell to the photodetector and detecting the fluorescence; a photodetector temperature control block for keeping the photodetector at a constant temperature; and a temperature control unit having a simultaneous temperature control block united with both the temperature control blocks and a temperature control system provided to be in contact with the simultaneous temperature control block to heat and/or cool the simultaneous temperature control block.

Abstract: The fluorescence detector includes: a flow cell provided on a flow passage for flowing a sample; a sample temperature control block for keeping the flow cell and the flow passage located on the sample inlet side of the flow cell at a constant temperature; an excitation optical system; a fluorescence optical system having a photodetector and used for guiding fluorescence emitted from a sample flowing through the flow cell to the photodetector and detecting the fluorescence; a photodetector temperature control block for keeping the photodetector at a constant temperature; and a temperature control unit having a simultaneous temperature control block united with both the temperature control blocks and a temperature control system provided to be in contact with the simultaneous temperature control block to heat and/or cool the simultaneous temperature control block.

Abstract: A sample cooler has a thermostatic chamber containing a heat-conducting block on which vessels containing liquid samples are set. A control unit activates a cooling mechanism of the air cooling type to cool the air inside the thermostatic chamber. Thereafter, when the temperature or humidity inside the thermostatic chamber is detected to have reached a specified level, when condensation of dew is detected inside the thermostatic chamber, or when a predetermined time has elapsed, the control unit starts to operate another cooling mechanism of the direct cooling type to cool the heat-conducting block, such that the samples can be cooled directly and quickly under a dehumidified condition without causing dew condensation.

Abstract: When a signal for filling up with or substituting a mobile phase is externally transmitted to a control part, the control part switches a valve for connecting a channel from a pump part to a sampling needle through a sampling loop and moves the sampling needle toward a drain port. Thus, a channel is formed through a mobile phase container.fwdarw.a pump.fwdarw.the valve.fwdarw.the sampling loop.fwdarw.the sampling needle.fwdarw.the drain port. In this channel state, the control part drives the pump at a high speed for substituting the channel connecting the pump and the sampling needle by a desired mobile phase.

Abstract: An ultraviolet and visible light absorbance detector uses a flow cell having a sample cell opening and a reference opening formed therethrough extending parallel to each other. The reference opening has a cross-sectional shape which is elongated in a direction perpendicular to the direction of its extension. An optical system causes an image of a slit to be formed with dispersed light over an area which includes light-receiving windows of both these openings, and portions of the dispersed light, after passing through these openings, are individually detected by light-receiving elements of a light-receiving device. Since the reference opening has an increased sectional area and its light throughput is increased, the absorbance noise due to the reference opening is reduced and the overall S/N ratio of the detector is improved.

Abstract: In order to satisfy both of high-sensitivity and low-sensitivity applications with no replacement of a flow cell, a photodetector (30) is divided into four portions (44-1, 44-2, 44-3, 44-4) by a first straight line (40) which is perpendicular to a direction of movement of a slit image (6) and a second straight line (42) which is inclined with respect to the direction of movement of the slit image (6) to intersect with the first straight line (40). Assuming that S.sub.1, S.sub.2, S.sub.3 and S.sub.4 represent intensity levels of detection signals of the photodetector portions respectively, the signals are processed along the following equations in analysis and preparative modes respectively:Sa=c{(S.sub.2 +S.sub.3)--(S.sub.1 +S.sub.4)}/{(S.sub.2 +S.sub.3)+(S.sub.1 +S.sub.4)]}Sp=c{(S.sub.1 +S.sub.2)--(S.sub.3 +S.sub.4)}/{(S.sub.1 +S.sub.2)+(S.sub.3 +S.sub.4)]}.