CN115656406A

CN115656406A - Ultra-high performance liquid chromatography automatic sample introduction device and control method

Info

Publication number: CN115656406A
Application number: CN202211332324.6A
Authority: CN
Inventors: 周雅雯; 周小靖
Original assignee: Zhejiang Fuli Analytical Instruments Co ltd
Current assignee: Zhejiang Fuli Analytical Instruments Co ltd
Priority date: 2022-10-28
Filing date: 2022-10-28
Publication date: 2023-01-31

Abstract

The invention relates to an ultra-high performance liquid chromatography automatic sample introduction device and a control method. The device comprises: the stator of the six-way rotary switching valve is provided with a first notch communicated with the mobile phase inflow valve port, and the first notch is located at the circumferential position of the mobile phase inflow valve port. The scheme can reduce the time for cutting off the flow of the chromatographic column.

Description

Ultra-high performance liquid chromatography automatic sample introduction device and control method

Technical Field

The invention relates to the technical field of ultra-high performance liquid chromatography analysis, in particular to an automatic sampling device and a control method for ultra-high performance liquid chromatography.

Background

High performance liquid chromatography (hereinafter, HPLC) is a common method for separating and analyzing samples, and a sample injection device is a module or a structure for introducing a target sample into a chromatographic system for analysis. Since the advent of the rotary switching valve (us patent 3411525) in 1965, the manner in which the sample is introduced into the chromatography system and the sample introduction device have been substantially fixed, and there has been a subsequent structural expansion that has been similar in the basic manner.

The switching valve used in the HPLC system at present is generally a two-position rotary valve, and has two flow path states of LOAD and INJECT; when the valve flow path is in the LOAD state, the sample flow path is separated from the analysis flow path, the mobile phase of the analysis flow path directly enters the chromatographic column, and the sample flow path can be independently sampled by an injector or other structures; when the valve flow path is in the INJECT state, the sample in the sample flow path enters the system flow path to perform the separation analysis of the target sample. Because the system flow path is connected with the valve port of the stator, when the valve flow path is switched from one state to another state, the flow path on the stator of the switching valve is not communicated in the switching process, namely, a cut-off flow is necessarily existed in the valve switching process, no liquid flows through the chromatographic column in the process, and the instantaneous flow rate of the chromatographic column is 0; for example, when a traditional automatic sample injector is used, the six-way valve is in the input state when the system is in the default state, the state of the sampling process is the LOAD state in the whole sample injection process, and when sampling is performed, the valve is switched from the input state to the LOAD state firstly, and a 60-degree cut-off angle of a chromatographic column exists; during sample injection, the valve is switched from LOAD back to INJECT, the cut-off angle of the chromatographic column of 60 degrees still exists, the two angles are added, and the cut-off angle of the chromatographic column is 120 degrees in total in the whole sample injection process.

With the continuous development of the technology, an ultra high performance liquid chromatography system (hereinafter referred to as UHPLC) with better separation and analysis effects is used for gradually replacing HPLC to carry out conventional separation and analysis on a sample; although the analysis effect of the UHPLC system is better than that of the conventional HPLC system, the using pressure of the UHPLC system is much higher than that of the HPLC system, the common pressure of the HPLC is 5-20 MPa, and the common pressure of the UHPLC is 40-80 MPa, so the problem of the flow cutoff of a chromatographic column is undoubtedly more obvious, and the influence on the UHPLC system is more obvious.

Therefore, an automatic sample feeding device and method for ultra-high performance liquid chromatography, which can reduce the flow-breaking time of the chromatographic column, are needed.

Disclosure of Invention

Therefore, it is necessary to provide an automatic sample introduction device and a control method for ultra-high performance liquid chromatography, which aim at the problem of long flow-off time of a chromatographic column.

An ultra high performance liquid chromatography autosampler apparatus, said apparatus comprising: the device comprises a sampling device, a cleaning device, a waste liquid flow path, an injector, a two-position three-way valve and a six-way rotary switching valve, wherein a stator of the six-way rotary switching valve is provided with a first notch communicated with a mobile phase inlet valve port, and the first notch is positioned at the circumferential position of the mobile phase inlet valve port.

In one embodiment, the six-way rotary switching valve comprises a stator and a rotor, wherein the stator is provided with six valve ports and a first notch groove which is a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port and a sixth valve port in sequence, the first valve port is a flowing phase inlet valve port, and the first notch groove is positioned between the first valve port and the second valve port, is communicated with the first valve port and is not communicated with the second valve port; the included angle between the second valve port and the third valve port is 60 degrees, and the included angle between the third valve port and the fourth valve port is 60 degrees; the rotor is provided with three notches in the circumferential direction corresponding to the valve port position, namely a second notch, a third notch and a fourth notch, the radian of the second notch and the third notch is 60 degrees, the included angle between the fourth notch and the second notch is equal to the radian of the first notch, and the sum of the radian of the fourth notch, the radian of the first notch and the included angle between the fourth valve port and the fifth valve port is 180 degrees; wherein the radian of the first notch is set as alpha, the radian of the fourth notch is set as beta, and the radian is more than 0 degrees and less than alpha <60 degrees, and the radian is more than 120 degrees and less than alpha and less than beta <180 degrees and less than 2 degrees.

In one embodiment, the outlet of the transfusion pump is connected with the first valve port, the chromatographic column is connected with the second valve port, the needle seat is connected with the third valve port, the waste liquid flow path is connected with the fourth valve port, the two-position three-way valve is connected with the fifth valve port, and the sampling needle is connected with the sixth valve port.

In one embodiment, the sampling device comprises a needle seat and a sampling needle which are connected in a sealing way.

In one embodiment, the automatic sample introduction device for ultra-high performance liquid chromatography further comprises a controller for controlling the action of the six-way rotary switching valve, the sampling needle, the two-position three-way valve, the injector or the cleaning device.

In one embodiment, the diameter of the first notch groove in the circumferential direction ranges from 3mm to 5mm, the diameters of six valve ports arranged on the stator range from 0.1mm to 0.3mm, and the radian distance between the first notch groove and the second valve port is not less than 15 degrees, namely alpha is not less than 15 degrees and not more than 45 degrees, and beta is not less than 135 degrees and not more than 165 degrees and not more than 2 degrees.

In one embodiment, α is 15 ≦ α ≦ 45 ° and β =135 ° - α.

In one embodiment, the radian measure α of the first notch is 15 ° and the radian measure β of the fourth notch is 120 °.

An ultra-high performance liquid chromatography automatic sample introduction control method applied to the ultra-high performance liquid chromatography automatic sample introduction device comprises the following steps:

receiving a signal to be injected;

controlling the six-way rotary switching valve to enter an INJECT state, and keeping the sampling needle in the needle seat for sealing; when the input is in the input state, a fourth notch of a rotor of the six-way rotary switching valve is communicated with a first valve port and a sixth valve port of a stator, a second notch is communicated with a second valve port and a third valve port, and a third notch is communicated with the fourth valve port and a fifth valve port;

judging whether the liquid discharge cleaning time of the sampling equipment is reached;

if the drainage cleaning time of the sampling equipment is up, controlling the six-way rotary switching valve to enter the LAOD state; when the LAOD state is reached, the second notch of the rotor of the six-way rotary switching valve is communicated with the first valve port and the second valve port of the stator, the third notch is communicated with the third valve port and the fourth valve port, and the fourth notch is communicated with the fifth valve port and the sixth valve port;

controlling the sampling needle to move to the cleaning seat for cleaning, moving to a sample bottle to absorb a target amount of sample after cleaning is finished, then moving the sampling needle to the cleaning seat for cleaning, and controlling the sampling needle to move to the needle seat for sealing after cleaning is finished again;

controlling the six-way rotary switching valve to enter a PRE state and keeping a preset time length; when the switching valve is in a PRE state, a second notch of a rotor of the six-way rotary switching valve is communicated with a second valve port and a first notch of a stator, and a fourth notch is communicated with the first valve port and a sixth valve port.

And controlling the six-way rotary switching valve to enter the INJECT state again, and finishing the sample injection.

In one embodiment, after determining whether the drain cleaning time period for the sampling device is reached, the method comprises: if the liquid discharge cleaning time of the sampling equipment is not reached, controlling the two-position three-way valve to be switched to one path of the injection liquid, and controlling the injector to suck the liquid; and controlling the two-position three-way valve to be switched to the six-way rotary switching valve for one way, and controlling the liquid discharge and cleaning of the injector.

In the automatic sampling device and the control method for the ultra-high performance liquid chromatography, the first notch groove is arranged in the six-way rotary switching valve 110, the flowing phase inlet valve port is communicated with the first notch groove, the angle of the flowing phase inlet valve is increased, and in the switching process of each flow path state, the rotor rotates in a larger range to ensure that the rotor is communicated with other valve ports and the flowing phase inlet valve port and the first notch groove, so that the flow-cutoff time of a system is shortened; the switching of three states can be realized only by using a single six-way rotary switching valve 110, the whole structure of the device is simple, and the pipeline connection is simple.

Drawings

FIG. 1 is a schematic diagram of an automatic sample injection device for ultra high performance liquid chromatography in one embodiment;

FIG. 2 is a schematic structural diagram of a stator of the six-way rotary switching valve in one embodiment;

FIG. 3 is a schematic structural diagram of a rotor of the six-way rotary switching valve in one embodiment;

FIG. 4 is a schematic structural diagram illustrating an INJECT state of the six-way rotary switch valve in one embodiment;

FIG. 5 is a schematic view of the LAOD state of the six-way rotary switch valve in one embodiment;

FIG. 6 is a schematic diagram of the PRE state of the six-way rotary switch valve in one embodiment;

FIG. 7 is a schematic diagram illustrating a connection structure of the automatic sample introduction device for ultra high performance liquid chromatography in a LAOD state in one embodiment;

FIG. 8 is a schematic diagram showing a connection structure of the automatic sample introduction apparatus for ultra high performance liquid chromatography in a PRE state in one embodiment;

FIG. 9 is a schematic flow chart of an automatic sample injection control method for ultra high performance liquid chromatography in one embodiment.

Reference numerals: an ultra-high performance liquid chromatography automatic sample introduction device 100; a six-way rotary switching valve 110; a stator 101; a first valve port 111; a second valve port 112; a third valve port 113; a fourth valve port 114; fifth port 115; sixth port 116; the first notch 117; a rotor 102; a second notch 1011; a third notch 1012; a fourth engraved groove 1013; a sampling needle 120; a needle hub 130; a waste liquid flow path 140; a two-position three-way valve 150; an injector 160; a cleaning device 170; a cleaning base 171; a purge pump 172; a solvent selector valve 173; a controller 180; an infusion pump 200; a chromatography column 300; a detector 400.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings to facilitate the description of the application and to simplify the description, and are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be constructed in operation as a limitation of the application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "plurality" or "a plurality" means two or more unless specifically limited otherwise.

It should be understood that the structures, ratios, sizes, and the like shown in the drawings are only used for matching the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the practical limit conditions of the present application, so that the modifications of the structures, the changes of the ratio relationships, or the adjustment of the sizes, do not have the technical essence, and the modifications, the changes of the ratio relationships, or the adjustment of the sizes, are all within the scope of the technical contents disclosed in the present application without affecting the efficacy and the achievable purpose of the present application.

At present, the pressure of the chromatographic column is generated by flowing the mobile phase of the system through the chromatographic column, and if the flow is cut off, namely no mobile phase passes through the chromatographic column, the instantaneous pressure of the system is 0; certainly, because of the existence of the volumes of the pipeline and the chromatographic column, certain buffering exists, the actual pressure drop speed has certain time difference and is not instantaneous, but a relatively large pressure drop exists in the valve cutting process, and the impact is caused on column head packing of the chromatographic column. The packing tends to collapse after multiple impacts, which results in poor chromatographic column peak shape and separation effect (typically, bifurcation peak) after the sample enters the system, so the service life of the chromatographic column is usually characterized by the number of sample injections. In order to reduce the flow-cutoff time of the chromatographic column, the application provides an automatic sampling device 100 for ultra-high performance liquid chromatography, wherein a first notch groove is arranged in a six-way rotary switching valve 110, a first valve port is communicated with the first notch groove, the angle of a mobile phase flowing into the valve is increased, three notch grooves are arranged on a rotor, the distances and the radians of the three notch grooves are set, the normal operation of various flow path states is ensured, and the flow-cutoff time of a system is shortened.

In one embodiment, as shown in fig. 1 and 2, there is provided an ultra high performance liquid chromatography autosampler device 100, the device comprising: the device comprises a sampling device, a cleaning device 170, a waste liquid flow path 140, an injector 160, a two-position three-way valve 150 and a six-way rotary switching valve 110, wherein a stator 101 of the six-way rotary switching valve 110 is provided with a first notch 117 communicated with a mobile phase inflow valve port, and the first notch 117 is positioned at the circumferential position of the mobile phase inflow valve port.

The ultra-high performance liquid chromatography automatic sample introduction device 100 can be applied to an HPLC system and an UHPLC system, the infusion pump 200 delivers a mobile phase of a system, the ultra-high performance liquid chromatography automatic sample introduction device 100 automatically introduces a sample, the chromatographic column 300 analyzes the sample, and the detector 400 connected with the chromatographic column 300 is responsible for detecting the sample.

In the automatic sample introduction device 100 for ultra-high performance liquid chromatography, the first notch groove is arranged in the six-way rotary switching valve 110, the mobile phase inflow valve port is communicated with the first notch groove, so that the angle of the mobile phase inflow valve is increased, and in the switching process of the states of all flow paths, the rotor rotates in a large range to ensure that the rotor is communicated with other valve ports and the mobile phase inflow valve port and the first notch groove, so that the cut-off angle of the system is reduced; the switching of three states can be realized only by using a single six-way rotary switching valve 110, the whole structure of the device is simple, and the pipeline connection is simple.

In one embodiment, as shown in fig. 1 to 8, the six-way rotary switching valve 110 includes a stator 101 and a rotor 102, the stator 101 is provided with six valve ports and a first notch 117, which are a first valve port 111, a second valve port 112, a third valve port 113, a fourth valve port 114, a fifth valve port 115 and a sixth valve port 116 in sequence, the first valve port 111 is a mobile phase inflow valve port, the first notch 117 is located between the first valve port 111 and the second valve port 112, is communicated with the first valve port, is not communicated with the second valve port, an included angle between the second valve port 112 and the third valve port 113 is 60 °, and an included angle between the third valve port 113 and the fourth valve port 114 is 60 °; the rotor 102 is provided with three notches in the circumferential direction corresponding to the valve port position, which are respectively a second notch 1011, a third notch 1012 and a fourth notch 1013, the radians of the second notch 1011 and the third notch 1012 are 60 degrees, the included angle between the fourth notch 1013 and the second notch 1011 is equal to the radian of the first notch 117, and the sum of the radians of the fourth notch 1013, the radian of the first notch 117 and the included angle between the fourth valve port 114 and the fifth valve port 115 is 180 degrees; wherein the radian of the first chamfer 117 is set to alpha and the radian of the fourth chamfer 1013 is set to beta, which satisfies 0 deg. < alpha <60 deg., 120 deg. -alpha < beta <180 deg. -2 deg..

The first port 111, the second port 112, the third port 113, the fourth port 114, the fifth port 115 and the sixth port 116 are non-circumferentially and uniformly distributed. The radians of the second, third and

fourth notches

1011, 1012, 1013 are not equal in the rotor, as shown in fig. 3, the rotor 102 has 3 notches with different lengths, the radians of the second and

third notches

1011, 1012 are 60 °, the radians of the fourth notch 1013 are β, and the angles between the fourth notch 1013 and the other two notches are α and 180 ° - α - β, respectively. As shown in FIG. 2, the first port 111 is connected to the first notch 117, the angle of the first notch 117 in the circumferential direction is α, and the included angle between the fourth port 114 and the fifth port 115 is 180 ° - α - β.

In one embodiment of the hplc automatic sample feeder 100, the outlet of the infusion pump 200 is connected to the first port 111, the column 300 is connected to the second port 112, the needle holder 130 is connected to the third port 113, the waste fluid channel 140 is connected to the fourth port 114, the two-position three-way valve 150 is connected to the fifth port 115, and the sampling needle 120 is connected to the sixth port 116.

According to the automatic sampling device for the ultra-high performance liquid chromatography, the six valve ports are respectively connected with the infusion pump, the chromatographic column, the needle seat, the waste liquid flow path, the two-position three-way valve and the sampling needle, so that the ultra-high performance liquid chromatography automatic sampling device can be cleaned to ensure the purity of a sample, and the sample analysis is more accurate.

In one embodiment, as shown in fig. 1, 7 and 8, the sampling device comprises a needle hub 130 and a sampling needle 120, wherein the needle hub 130 is connected with the sampling needle 120 in a sealing manner.

In one embodiment, as shown in fig. 1, 7 and 8, the hplc autoinjection device further includes: and an injector 160 connected to the two-position three-way valve 150.

In one embodiment, as shown in fig. 1, 7 and 8, the hplc autoinjection device further comprises a cleaning device 170.

The cleaning device 170 includes a cleaning base 171, a cleaning pump 172, and a solvent selection valve 173, and the solvent selection valve 173 may be connected to various cleaning solvents, such as a strong cleaning solution, a medium cleaning solution, and a weak cleaning solution. The cleaning solvent selection valve 173 can be connected with three different cleaning solvent liquid storage bottles, the controller 180 controls the valve position of the cleaning solvent selection valve 173, the cleaning pump 172 introduces the corresponding cleaning solvent into the cleaning seat 171 according to the set cleaning flow, and the outer wall of the sampling needle 120 is cleaned.

In one embodiment, as shown in fig. 1, 7 and 8, the hplc automatic sample introduction apparatus further comprises a controller 180 for controlling the operation of the six-way rotary switching valve 110, the sampling needle 120, the two-position three-way valve 150, the injector 160 or the cleaning device 170.

In one embodiment, the diameter of the first notch 117 in the circumferential direction is usually in a range of 3mm to 5mm, the diameter of six valve ports provided in the stator is 0.1mm to 0.3mm, the typical diameter is 0.2mm, the radian range of each valve port in the circumferential direction is 3 ° to 11.5 °, in order to ensure that the first notch is not communicated with the second valve port, the radian distance between the first notch 117 and the second valve port 112 is not less than 15 °, namely, α is not less than 15 ° and not more than 45 °, β is not less than 135 ° and not more than β and not more than 165 ° to 2 α.

Specifically, in terms of volume, the smaller the volume of the fourth notch 1013 is, the better the sampling effect is, that is, the smaller the radian is, the better the sampling effect is, then α is greater than or equal to 15 ° and less than or equal to 45 °, and β =135 ° - α. As an alternative embodiment, the arc α of the first notch 117 is 15 ° and the arc β of the fourth notch 1013 is 120 °.

In one particular embodiment, as shown in FIG. 1, two-position, three-way valve 150 is connected to injector 160; when the two-position three-way valve 150 is connected to the liquid storage bottle, the injector is communicated with the liquid storage bottle for storing the injection, and the injector can absorb the injection in the liquid storage bottle; when two-position three-way valve 150 is connected to fifth port 115, the syringe communicates with fifth port 115, and when six-way rotary switch valve 110 is in the INJECT state, the syringe can be pushed out to discharge its own air or replace the old injection liquid.

In a specific embodiment, as shown in fig. 4-6, the controller 180 controls the rotor 102 to rotate, and the six-way rotary switch valve 110 can be switched at any position to achieve three position states of LOAD, INJECT and PRE, where PRE is PRE-pressurized. The stator is combined with the rotor, and as shown in fig. 4 to 6, the thin line indicates the stator and the thick line indicates the rotor. The positions of the rotor and stator in the input state are shown in fig. 4, the positions of the rotor and stator in the LOAD state are shown in fig. 5, and the positions of the rotor and stator in the PRE state are shown in fig. 6.

In a specific embodiment, the theoretical range of α is 0 ° < α <60 °, and the range of β allowed value refers to three states of the six-way rotary switch valve 110:

in INJECT state:

furthermore, 0 DEG < alpha <60 DEG is administered

∴60°<90°-(α/2)<90°

The abovementioned conditions may be summarized as β >90 ° - (α/2);

the LOAD state needs to satisfy:

β >120 ° - (180 ° - α - β), i.e., β > (α -60 °), and also (0 ° < α <60 °), which equation holds true;

the PRE state needs to satisfy: (180 ° - α - β) > α, i.e., β <180 ° -2 α;

the angular difference between fourth port 114 and fifth port 115 is satisfied: (180 ° - α - β) > α, i.e., β <180 ° -2 α;

combining the above conditions, there are: 0 ° < α <60 °,120 ° - α < β <180 ° -2 α.

Specifically, the values are further optimized: considering that the diameter of the first notch 117 in the circumferential direction is generally 3-5 mm, the diameter of the valve port is generally 0.1-0.3mm, and the maximum radian of the valve port in the circumferential direction is 11.5 ° (taking 3mm and 0.3 mm), it is recommended to reserve 15 ° allowance between the groove and the disconnected valve port in order to ensure that the first notch and the second valve port are not communicated. The further optimization process of the value ranges of the alpha and the beta comprises the following steps:

preferred α ∈ [15 °,45 ° ];

the angular difference between fourth port 114 and fifth port 115 also satisfies the following conditions: 15 degrees + alpha is less than or equal to (180 degrees-alpha-beta) and less than or equal to 45 degrees;

∴15°+α≤45°

alpha has more accurate value range, alpha belongs to [15 degrees, 30 degrees ]

(180-alpha-beta) is not less than 15 degrees + alpha, i.e. beta is not more than 165-2 alpha

(180-alpha-beta) is less than or equal to 45 degrees, namely beta is more than or equal to 135-alpha

∴135°-α≤β≤165°-2α

Combining the above conditions, there are: alpha is more than or equal to 15 degrees and less than or equal to 45 degrees, beta is more than or equal to 135 degrees and less than or equal to beta is more than or equal to 165 degrees and less than or equal to 2 degrees.

More specifically, from the viewpoint of volume, the smaller the engraved volume, the better, and the smaller the volume, the smaller the diffusion of the sample in the flow path, so β takes the minimum value, and satisfies:

for example, the values α =15 °, β =120 ° satisfy the optimum condition.

In an embodiment, as shown in fig. 9, there is provided an ultra high performance liquid chromatography autoinjection control method applied to the ultra high performance liquid chromatography autoinjection apparatus described in the above embodiment, including:

and S510, receiving a signal ready for sample injection.

S520, controlling the six-way rotary switching valve to enter an INJECT state, and keeping the sampling needle in the needle seat for sealing; when the input state is in the input state, a fourth notch of the rotor of the six-way rotary switching valve is communicated with the first valve port and the sixth valve port of the stator, the second notch is communicated with the second valve port and the third valve port, and the third notch is communicated with the fourth valve port and the fifth valve port.

The system is in an INJECT state by default, as shown in figure 1, at the moment, the sampling needle is positioned in the needle seat, the sampling needle and the needle seat are completely sealed, the mobile phase output by the infusion pump enters the sixth valve port through the first valve port, flows through the sampling needle and the needle seat, then enters the third valve port of the valve, finally flows out of the second valve port and enters the chromatographic column. At this time, the drain cleaning time of the syringe is set to discharge bubbles in the syringe.

S530, judging whether the liquid discharge cleaning time of the sampling equipment is up.

S540, if the drain cleaning time of the sampling device is up, controlling the six-way rotary switching valve to enter a LAOD state; when the LAOD state is reached, the second notch of the rotor of the six-way rotary switching valve is communicated with the first valve port and the second valve port of the stator, the third notch is communicated with the third valve port and the fourth valve port, and the fourth notch is communicated with the fifth valve port and the sixth valve port.

Specifically, as shown in fig. 7, when the system enters the LOAD state from the INJECT state, the rotor 102 rotates 60 ° counterclockwise, the shut-off angle of the column 300 during the switching process is α, and after the system is switched to the LOAD state, the liquid with the preset system pressure in the sampling needle 120 releases the excess pressure from the waste port connected to the waste flow path 140 through the fourth port 114. In this state, the syringe 160 is connected to the fifth port 115 of the six-way rotary switch valve 110 via the two-position three-way valve 150, and is connected to the sampling needle 120 via the sixth port 116.

And S550, controlling the sampling needle to move to the cleaning seat for cleaning, moving to the sample bottle to absorb a target amount of sample after cleaning, moving the sampling needle to the cleaning seat for cleaning, and controlling the sampling needle to move to the needle seat for sealing after cleaning again.

Specifically, the motor controls and moves the sampling needle, the sampling needle is moved out of the needle seat, moved to the position of the cleaning seat and inserted, a solvent selection valve of the cleaning pump selects a set cleaning solution, the outer wall of the sampling needle is generally cleaned according to the sequence of strong cleaning, medium cleaning and weak cleaning according to the set cleaning time of the cleaning pump, and the sampling needle can be directly used or used as weak cleaning solution for samples which are not easy to leave residues; wherein, the cleaning seat and the needle seat can also be combined into a whole, and the bottom of the needle seat is provided with a waste liquid port and other structures. The motor controls the sampling needle to move the sampling needle out of the cleaning seat to the position of the sample bottle 190, and then the injector draws the sample in the sample bottle according to the set amount. The motor controls the sampling needle, the sampling needle is moved out of the sample bottle, moved to the position of the cleaning seat and inserted, the solvent selection valve of the cleaning pump selects the set cleaning liquid, and the outer wall of the sampling needle is generally cleaned according to the strong, medium and weak sequence according to the set time for cleaning the cleaning pump. The motor controls the sampling needle, moves the sampling needle out of the cleaning seat, moves the sampling needle to the needle seat, and inserts the sealing.

S560, controlling the six-way rotary switching valve to enter a PRE state and keeping a preset time length; when the switching valve is in a PRE state, a second notch of a rotor of the six-way rotary switching valve is communicated with a second valve port and a first notch of a stator, and a fourth notch is communicated with the first valve port and a sixth valve port.

Specifically, as shown in fig. 8, the rotor is rotated counterclockwise by α degrees, and the PRE state is entered, and in the PRE state, the infusion pump, the sampling needle, the needle holder, and the column are all in the same flow path, and the column is not stopped. The system can be switched to PRE for a period of time because the infusion pump is running all the time, the column is in the same flow path as the sampling needle, and the system fluid will actively pressurize the sample in the sampling needle. The volume of the sample taken by the sampling needle is generally half of the volume of the sampling needle, so that in this state, no additional diffusion of the sample occurs in the front end of the sampling needle, the needle seat and the third valve port. The sample introduction system waits for a certain time, such as 1 second, in the PRE state, and after the sample pressurization is finished, the system is switched to the INJECT state, and the pressure of the sample entering the chromatographic column is consistent with the system pressure, so that the back diffusion caused by the pressure difference between the sample and the system can not be caused. Wherein the PRE state is a PRE-stress state.

And S570, controlling the six-way rotary switching valve to enter an INJECT state again, and finishing sample injection.

Wherein, the system switches to INJECT state, and the sample enters the chromatographic column through the sampling needle, the needle seat, the third valve port and the second valve port for separation and analysis.

The angle of column cutoff 2 α is the whole process from S510 to S570. For example, taking α =15 ° as an example, the whole process theoretically cuts off 30 ° and reduces the cutting off time to 1/4 of the original cutting off time compared with 120 ° in the prior art; if the limit condition is considered, the minimum alpha can be taken to be 3 degrees by using the notching arc with the circumference diameter of 5mm and the notching diameter of 0.1mm, and the current breaking time is only 1/20 of the prior art.

According to the automatic sampling control method for the ultra-high performance liquid chromatography, the first notch groove in the six-way rotary switching valve and the control mode are arranged, so that the flow breaking time of the chromatographic column is short, and the influence of pressure impact on the chromatographic column is reduced; and, increased the PRE state and carried out the pressurization to the sample that gets into the syringe, avoided when getting into the chromatographic column, the sample that causes because the pressure differential reversely diffuses.

In one embodiment, after determining whether the drain cleaning time period for the sampling device is reached, the method comprises: s580, if the liquid discharge cleaning time of the sampling device is not reached, controlling the two-position three-way valve to be switched to one injection path, and controlling the injector to suck liquid; and S590, controlling the two-position three-way valve to be switched to one path of the six-way rotary switching valve, and controlling the injector to discharge liquid to clean the sampling needle.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An ultra-high performance liquid chromatography autosampler device, the device comprising: the device comprises a sampling device, a cleaning device, a waste liquid flow path, an injector, a two-position three-way valve and a six-way rotary switching valve, wherein a stator of the six-way rotary switching valve is provided with a first notch communicated with a mobile phase inlet valve port, and the first notch is positioned at the circumferential position of the mobile phase inlet valve port.

2. The automatic sampling device for ultra-high performance liquid chromatography according to claim 1, wherein the six-way rotary switch valve comprises a stator and a rotor, the stator is provided with six valve ports and a first notch, and the six valve ports are sequentially a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port and a sixth valve port, the first valve port is a mobile phase inflow valve port, the first notch is positioned between the first valve port and the second valve port, is communicated with the first valve port and is not communicated with the second valve port, the included angle between the second valve port and the third valve port is 60 degrees, and the included angle between the third valve port and the fourth valve port is 60 degrees;

the rotor is provided with three notches in the circumferential direction corresponding to the valve port, wherein the notches are a second notch, a third notch and a fourth notch respectively, the radians of the second notch and the third notch are 60 degrees, the included angle between the fourth notch and the second notch is equal to the radian of the first notch, and the sum of the radian of the fourth notch, the radian of the first notch and the included angle between the fourth valve port and the fifth valve port is 180 degrees; the radian of the first notch is set to be alpha, the radian of the fourth notch is set to be beta, and the conditions that the alpha is more than 0 degrees and less than 60 degrees, the beta is more than 120 degrees and less than 180 degrees and less than 2 degrees are met.

3. The automatic sampling device for ultra-high performance liquid chromatography according to claim 2, wherein the outlet of the infusion pump is connected with the first valve port, the chromatographic column is connected with the second valve port, the needle seat is connected with the third valve port, the waste liquid flow path is connected with the fourth valve port, the two-position three-way valve is connected with the fifth valve port, and the sampling needle is connected with the sixth valve port.

4. The automatic sampling device for the ultra-high performance liquid chromatography according to claim 1, wherein the sampling device comprises a needle seat and a sampling needle which are hermetically connected.

5. The HPLC autosampler device of any of claims 1-4, further comprising a controller for controlling the operation of the six-way rotary switch valve, the sampling needle, the two-position three-way valve, the injector or the washing device.

6. The ultra-high performance liquid chromatography autoinjection device of claim 1, wherein the diameter of the first notch groove in the circumferential direction ranges from 3mm to 5mm, the diameters of six valve ports arranged on the stator range from 0.1mm to 0.3mm, and the radian distance between the first notch groove and the second valve port is not less than 15 degrees, namely, alpha is more than or equal to 15 degrees and less than or equal to 45 degrees, and beta is more than or equal to 135 degrees and less than or equal to beta is more than or equal to 165 degrees and less than or equal to 2 degrees.

7. The automatic sample introduction device for ultra high performance liquid chromatography according to claim 1 or 6, wherein α is not less than 15 ° and not more than 45 °, and β =135 ° - α.

8. The automatic sampling device for the ultra-high performance liquid chromatography according to claim 7, wherein the radian alpha of the first notch is 15 degrees, and the radian beta of the fourth notch is 120 degrees.

9. An ultra-high performance liquid chromatography automatic sample introduction control method applied to the ultra-high performance liquid chromatography automatic sample introduction device according to any one of claims 1 to 8, comprising the following steps:

receiving a signal to be injected;

10. The method of claim 9, after determining whether the drain cleaning period for the sampling device has been reached, comprising:

if the liquid discharge cleaning time of the sampling equipment is not reached, controlling the two-position three-way valve to be switched to one path of the injection liquid, and controlling the injector to suck the liquid;

and controlling the two-position three-way valve to be switched to the six-way rotary switching valve for one way, and controlling the liquid discharge and cleaning of the injector.