Hitachi, Ltd.

Sadabumi Ohnuma

Kenji Yasuda

Junkichi Miura

Yoshinori Takata

Harumi Tsuruta

Yoshio Fujii

Kiwao Seki

Yoshiaki Yamada

Wataru Kato

Genzo Hirata

Katsuo Tsukada

Mitsuo Shimada

Hiromi Takiuchi

Sachio Tomimatsu

In a liquid chromatographic analyzer apparatus, there is possibility that a flow cell is damaged when a flow passage is blocked and the inner pressure is increased. In order to prevent damage to the apparatus, liquid is prevented from leaking inside the apparatus. The liquid is discharged externally through a liquid discharging tube. A spring member is provided between the flow cell and the seal in a tube connecting portion to allow liquid to leak when the pressure is increased. Further, a light-proof tube for blocking light is connected to the flow cell to allow the leaked liquid to flow through the light-proof tube.

Liquid analyzing apparatus

In the analysis of hemoglobins in blood samples by chromatography, an increase in the pressure in a flow passage line is suppressed, a separation column is made durable against prolonged use by supplying phosphate-based buffer solutions as eluting solutions to a separation column and a solution containing not more than 100 mM of S-(carboxyalkyl)-L-cysteine and phosphate-based buffer agent thereto in the course of a series of analyzing steps.

Solution for suppressing deterioration of a separation column for

In the analysis of hemoglobins in blood samples by chromatography, an increase in the pressure in a flow passage line is suppressed, a separation column is made durable against prolonged use by supplying phosphate-based buffer solutions as eluting solutions to a separation column to a separation column and a solution containing not more than 100 mM of S-(carboxyalkyl)-L-cysteine and phosphate-based buffer agent thereto in the course of a series of analyzing steps.

Method of analyzing hemoglobins

A plunger pump for supplying solution in accordance with an extrusion action of a plunger within a pump chamber. The plunger pump includes a cleaning chamber sealed by a seal member around and relative to the plunger, with a cleaning liquid inlet-side flow conduit and a cleaning liquid outlet-side flow conduit for communicating with the cleaning chamber, respectively. A mechanism isolates one of the inlet- and outlet-side flow conduits from the atmosphere and releases the other to an atmosphere under a condition where the cleaning liquid inlet- or outlet-side flow conduits are filled with the cleaning liquid. If the seal member in sliding contact with the plunger is degraded or aged, it is possible to observe a leakage of the liquid from the pump chamber along a sealing face between the seal member and the plunger.

Plunger pump

A plurality of liquid mobile phases stored in a plurality of reservoirs respectively are filled and pumped by a dual pump driven by a stepping motor, through valves complementarily subjected to on-off control by a gradient programmer. The dual pump has two pistons in contact with the periphery of a cam in opposition to each other at 180 degrees, which pistons fill and pump the liquid mobile phases by linear reciprocation along the contour of the cam with the rotation of the cam. The radius of the cam linearly increases in the range from 0 to 180 degrees and linearly decreases in the range from 180 to 360 degrees at the same rate as when it increases. An electric signal is produced from a timing device during a period from the rotational positions of the cam reaches 0 and 180 degrees to a predetermined rotational positions. The liquid mobile phase delivered from the dual pump is supplied to a pressure transducer, and after passing through it, supplied to a column through an injector for injecting a specimen. The components into which the specimen is separated are detected by a detector. When the timing device detects that the cam is positioned in intervals from 0 and 180 degree to a predetermined angle therefrom, the motor control circuit drives the stepping motor at high speed during period from a time which the time derivative of the back pressure signal from the pressure transducer reaches value smaller than a predetermined value to a time it reaches value larger than the predetermined value.

Liquid chromatography apparatus

A high sensitivity absorptiometer comprises a light source lamp accompanied inevitably with heat generation, a sample container through which the light from the light source is transmitted and a detector device for detecting the light which has transmitted through the sample container. The light emitted from the light source lamp and directed to the sample container is adapted to pass through a chamber which is formed fluid-tight on a surface portion of the light source lamp or through a solid state optical conductor such as optical fiber having a light inlet end face closely fitted to the surface portion of the lamp, thereby to suppress movement and turbulence of air as caused by heat generated by the light source lamp with a view to excluding noise and drift ascribable to the air movement or turbulence phenomenon from the signal obtained from the detector device.

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Hitachi, Japan

Sadabumi Ohnuma