A liquid chromatograph capable of controlling the mixing ratio of mobile phase

Abstract

The present invention discloses a liquid chromatograph capable of controlling a mobile phase mixing ratio. The liquid chromatograph comprises a liquid injecting pump and a control system, wherein the liquid injecting pump comprises an N-component gradient valve (N is more than or equal to 2) and a tandem plunger pump, the N-component gradient valve is provided with N channels and is used for mixing liquids in the N channels, and the control system controls the opening duration of each channel according to the corresponding liquid ratio of each channel, controls the N channels to sequentially inject liquids to the tandem plunger pump according to a channel alignment manner, and adjusts the opening time ratio of the N channels according to the liquid loss ratio L1 of the first liquid injecting channel and the liquid loss ratio L2 of the final liquid injecting channel. With the liquid chromatograph of the present invention, the opening times of each channel are adjusted by regulating the gradient valve so as to calibrate the mixing ratio of the mobile phases.

Description

technical field [0001] The invention relates to the field of test and measurement, in particular to a liquid chromatograph capable of calibrating the mixing ratio of mobile phases. Background technique [0002] High-performance liquid chromatography is an important branch of chromatography. It uses liquid as the mobile phase and uses a high-pressure infusion system to connect a single solvent with different polarities or a mixed solvent with different proportions, buffer solution, etc. to the sample pump to be tested. The components of the sample to be tested are separated in the column and then enter the detector for detection, thereby realizing the qualitative and quantitative analysis of the sample. This method has become an important separation and analysis technique in the fields of chemistry, medicine, industry, agronomy, commodity inspection and legal inspection. High performance liquid chromatography (HPLC) is the instrument used for this analytical method. [0003...

AI Technical Summary

Problems solved by technology

[0005] refer to image 3 , this figure represents the relationship between the number of plunger steps and the amount of suction of the series plunger pump 202, the abscissa is the number of steps of the plunger, and the area of ​​the figure represents the amount of liquid absorption. Since the inlet check valve 205 and the outlet check valve 206 are passive Valves all have a certain response time (an inherent parameter of the device), so the series plunger pump 202 will have a period of time when it does not suck liquid at the beginning and end of each suction process, that is, image 3 The area of ​​s1 and s2 in is the amount of liquid lost, so it will lead to a deviation in the mixing ratio of the final mixed liquid

And because the infusion pump 102 is driven by a stepping motor, the proportional distribution of each channel in the quaternary gradient valve 201 is based on the number of steps of the motor, and has nothing to do with the flow rate of the liquid. When the number is 500, no matter what the flow rate is, the channel is opened when the number of steps is 500, but the liquid flow rate is different, which is caused by the change of the motor speed. Therefore, the inlet check valve 205 and the outlet Within the fixed response time of the one-way valve 206, at different flow rates, the series plunger pump 202 will produce different deviations at both ends of the suction process. For example, when the flow rate is 1ml / min, the response time corresponds to 20-step deviation, and when the flow rate is 2ml / min, the response time corresponds to 40-step deviation, so the mixing ratio will produce different deviations at different flow rates

[0006] As mentioned above, there is a lack of a liquid chromatograph that can accurately control the mixing ratio of mobile phase in the prior art

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