Hitachi-high-technologies Corporation

Kimihiko Ishii

Hironori Kaji

Masahito Ito

Yoshihiro Nagaoka

Kenji Hiraku

Kisaburo Deguchi

Kunihiko Takao

Daisuke Akieda

Katsutoshi Shimizu

Takefumi Yokokura

Naoya Yasuhara

Yumiko Ono

Eri Yamashita

Hiroshi Suzuki

Kenichiro Tokuo

Kiyotoshi Mori

Masaru Yamasaki

Yoshiaki Seki

Hiroyuki Wada

Mitsuhiko Ueda

A pump controller causes a first plunger pump and a second plunger pump connected in series or in parallel to perform intake and compression actions alternately at substantially constant cycles, sets a pressurizing chamber of one of the plunger pumps to a state of a higher pressure than the pressurizing chamber of the other plunger pump, and performs flow rate control by adjusting lift amounts of the first plunger and the second plunger. Thus, it is possible to provide a pump for liquid chromatograph, and a liquid chromatograph, which are capable of reducing pulsations even when an ejection flow rate is changed.

Pump for liquid chromatograph, and liquid chromatograph

Disclosed herein is a sample introducing apparatus which is designed such that the analytical flow path runs from the needle to the separation column without the flow path switching means placed at the downstream side of the needle. This design reduces dead volume, which in turn reduces the diffusion of the sample injected into the analytical flow path. Moreover, the absence of the flow path switching means at the downstream side of the needle to inject a sample into the analytical flow path eliminates connection of the pipe with the flow path switching means. This prevents the sample from remaining in the connecting part, thereby reducing sample carry-over and improving the accuracy of analysis.

Liquid chromatograph and sample introducing apparatus

It is possible to correctly determine whether a change in the pressure or flow rate is caused by normal opening and closing operations of a check valve and to monitor in real time whether an operation of a check valve is normal or abnormal in a liquid supply device. Light is introduced in the check valve and a change in the quantity of light transmitted through or reflected by the check valve, caused by the opening and closing of the valve is detected, so that the opening and closing operations of the check valve can be directly detected. The check valve is arranged in a pipe in the liquid supply device, and a change in the pressure in the pipe is monitored on the basis of a signal from a pressure sensor and a signal which represents the opening and closing of the check valve.

Liquid supply device using check valve and reactive liquid chromatography system

A liquid sample introducing apparatus capable of executing a process with high reliability and high speed is realized. An injection valve includes a sample storage loop connected to a mobile phase flow passage for supplying a sample to a detector of a liquid chromatograph apparatus. A sample is sucked in a needle through a valve and a pipe by a syringe, being introduced to the sample storage loop, being supplied to the mobile phase flow passage. A washing solution from a washing solution bottle is supplied to the needle by a washing unit through the valve and the pipe to wash the inner wall of the needle. The washing solution from the washing solution bottle is supplied to a washing tank by the washing unit through the valve and a pipe to wash the external wall of the needle in the washing tank.

Liquid sample analyzing apparatus and liquid sample introducing apparatus

Both a column having high-pressure resistance and capable of performing high-speed separation and analysis even with a small flow rate and a liquid chromatograph apparatus using the column are provided. A separation column according to the present invention has a monolithic rod being arranged in the center, being made of a porous material, and having a circular cross section, a filler layer arranged such that it encircles a circumferential surface of the monolithic rod, and a cylindrical support medium arranged outside the filler layer. The filler layer is formed by filling a tube-like gap between the monolithic rod and the support medium with particles or beads.

Separation column for liquid chromatograph apparatus and liquid chromatograph apparatus using thereof

Disclosed herein is a stable solvent delivery device capable of delivering solvent both at high pressure and at constant flow rate. A solvent delivery device comprises a plurality of plungers which reciprocate in the respective pump chambers including an eluent charge side pump chamber and an eluent discharge side pump chamber, a motor to reciprocate these plungers, a control unit to control the operation of the motor, valves which are respectively set at the eluent inlet and outlet of the eluent charge side pump chamber, a first sensor to measure the quantity of load received by the plunger in the eluent charge side pump chamber, and a second sensor to measure the pressure of the eluent discharged from the eluent discharge side pump chamber.

Solvent delivery device and analytical system

A pump device which accurately detects a flow rate of a pump, performs real-time control of the flow rate, and thus can suppress a flow rate error caused by occurrence of pulsation. Control of a pump rotation speed by a pressure sensor has low responsiveness in a low pressure region, and a correlation between a pressure and a flow rate is incomplete in a high flow rate region. With this taken into consideration, a flow rate sensor is disposed at an outlet port of a second pump. A position detection sensor detects a point where a first pump is shifted from a suction mode to a discharge mode. Moreover, the flow rate sensor detects that there is no discharge from the pump, and that there is discharge from the pump alone. Accordingly, a controller sets a rotation speed of a motor to a speed double the previous speed (double the normal rotation speed). When the flow rate sensor detects an increase in the flow rate at the outlet port of the second pump, the controller returns the rotation speed of the motor to a normal rotation speed. The rotation speed of the motor is controlled by accurate flow rate detection by the flow rate sensor. Thus, occurrence of pulsation can be suppressed.

Two-unit pump for liquid chromatograph with flow sensor arrangement

Disclosed herein is a separation column comprising a porous block covered with a coating wherein space-free adhesion is attainable therebetween by low temperature process without releasing octadecylsilyl bases and others from the porous block. A monolith rodis covered with a metal or resin coating. Then, the monolith rodcovered by the coatingis further covered with a rod retainermade of a low melting point metal (melting point 100-200 degrees C.) to form a column body. Since the rod retaineris formed by pressure molding at low temperature (100-200 degrees C.). It is therefore possible to absorb the surface irregularities of the monolith rodby the coatingwhile octadecylsilyl bases and others from are released when the retaineris formed. This allows the potential separation ability of the porous block to be brought out maximally.

Growing community of inventors

Hitachinaka, Japan

Kimihiko Ishii