Abstract: An analysis method is achieved in which pressure variation resulting from sample injection or passage switching by an autosampler does not exert an influence on the control of a liquid transfer pump. The liquid chromatograph analysis method comprises the steps of: transferring two or more types of eluents while changing a mixing ratio between the eluents; adjusting an amount of the transferred liquid within a predetermined time in a passage for the eluent transferred; injecting a sample in the passage; supplying to a separation column the eluent into which the sample is injected; separating a target component in the sample; and detecting the target component thus separated. In this method, control is exercised so as to synchronize a liquid transfer cycle of the eluent with the sample injecting operation and to implement the sample injecting operation at a timing rather than the pressure obtaining time.

Abstract: A high-pressure constant flow rate pump transfers a solvent from a low-pressure side liquid transfer system even if a difference between mixing ratios is large when solvents are mixed during high-pressure gradient liquid transfer. A pressure detection value from a second pressure sensor and a pressure detection value from a fourth pressure sensor are compared with each other. If the pressure detection value PA1 of the second pressure sensor is equal to or greater than the pressure detection value PA2 of the fourth pressure sensor, a second check valve comes into an opened state and operation is ended. If PA1 is less PA2, leakage determination is implemented. If it is determined that no leakage occurs, the type of the solvent is identified. A compression distance of a second plunger which is determined for each solvent and stored in a memory is added and the first plunger is driven.

Abstract: An analysis method is achieved in which pressure variation resulting from sample injection or passage switching by an autosampler does not exert an influence on the control of a liquid transfer pump. The liquid chromatograph analysis method comprises the steps of: transferring two or more types of eluents while changing a mixing ratio between the eluents; adjusting an amount of the transferred liquid within a predetermined time in a passage for the eluent transferred; injecting a sample in the passage; supplying to a separation column the eluent into which the sample is injected; separating a target component in the sample; and detecting the target component thus separated. In this method, control is exercised so as to synchronize a liquid transfer cycle of the eluent with the sample injecting operation and to implement the sample injecting operation at a timing rather than the pressure obtaining time.

Abstract: An image capture device is installed in an autosampler and captures an image data of a rack on which one or more vials are disposed. A data processing device analyzes the data captured by the image capture device and acquires information on a position at which the vial is disposed, and sample information attached to each of the vials, in association with each other. The data processing device constructs an optimum analysis program from the acquired vial position information and sample information, and an analysis condition set and inputted by an operator via an input device. The position of the vial and the sample information can be determined in a short period of time, because the position of the vial and the sample information is determined from the image data acquired by capturing an entire image of the rack with the vials disposed thereon.