阅读说明：本技术 一种用于液相色谱仪荧光检测器的流通池部件 (Flow cell component for liquid chromatograph fluorescence detector ) 是由 朱志华 马昱 徐伯元 邓琦 周兴 李明 许佳俊 于 2020-05-22 设计创作，主要内容包括：本发明公开了一种用于液相色谱仪荧光检测器的流通池部件,包括四棱柱核心体部件和一个流通池架部件。当被测组分进入该流通池的玻璃核心体后,在激发光的照射下,被测组分吸收激发光的光能后立刻进入激发态,处于激发态的分子是极不稳定的,立即退激发并发出比激发光波长更长的发射光,即荧光。发射的荧光会向各个方向传播,流通池的玻璃核心体其中两个相邻的玻璃外壁涂布高反射涂层,对通过的入射光和产生的荧光进行一定的集束,在入射光90度方向测量被测组分产生的荧光强度,从而实现对被测组分的定性定量分析。(The invention discloses a flow cell component for a fluorescence detector of a liquid chromatograph, which comprises a quadrangular prism core component and a flow cell frame component. When the component to be detected enters the glass core body of the flow cell, under the irradiation of the exciting light, the component to be detected enters the excited state immediately after absorbing the light energy of the exciting light, and the molecule in the excited state is extremely unstable, and immediately excites and emits the emitting light with the wavelength longer than that of the exciting light, namely fluorescence. The emitted fluorescence can be transmitted to all directions, the outer walls of two adjacent glasses in the glass core body of the flow cell are coated with high-reflection coatings, the passing incident light and the generated fluorescence are bundled to a certain extent, and the fluorescence intensity generated by the component to be detected is measured in the direction of 90 degrees of the incident light, so that the qualitative and quantitative analysis of the component to be detected is realized.)

1. A flow cell component for a fluorescence detector of a liquid chromatograph, comprising: a quadrangular prism core body part (2) with a cavity and a flow cell frame part (3); wherein the content of the first and second substances,

the quadrangular prism core body component (2) is composed of four pieces of non-fluorescent high-transmittance quartz glass, and the non-fluorescent high-transmittance quartz glass is vertical to form a central cavity; wherein, the outer walls of two adjacent non-fluorescent high-transmittance quartz glass are coated with a high-reflection mirror coating (4), and the mirrors face inwards; two non-fluorescence high-transmittance quartz glass surfaces without mirror surface coating are positioned in the light path of the incident light and the emergent light and are vertical to the height of the light path;

the flow cell frame member (3) comprises: a C-shaped inner support (5) and a C-shaped outer support (6); an emergent shading slit baffle (11) coated with a non-fluorescent all-black coating is fixed at the opening of the C-shaped inner support (5), and the center of the slit is superposed with the center of a fluorescent emergent light projection plane of the quadrangular prism core body component (2); a bracket fixing piece (12) coated with a non-fluorescent all-black coating is fixed at the opening of the C-shaped outer bracket (6);

the joint of the flow cell frame component (3) and the quadrangular prism core body component (2) is connected with a flow cell input end flow guide head (7) and a flow cell output end flow guide head (8);

the tail parts of the flow guide head (7) at the input end of the flow cell and the flow guide head (8) at the output end of the flow cell are both provided with a quadrangular protrusion (14), and the inner cavity of the protrusion part is opened in a horn mouth shape;

the bell mouth of the quadrangular prism-shaped bulge (14) enters the central cavity of the quadrangular prism core body part (2) and is tightly combined with the inner wall of the quadrangular prism core body part (2);

the shape and the installation mode of a quadrangular prism-shaped bulge (14) at the tail part of the flow cell input end flow guide head (7) are the same as those of the flow cell output end flow guide head (8).

2. The flow cell component for a fluorescence detector of a liquid chromatograph of claim 1, wherein the central cavity has a cross-section of 1.75 x 1.75 mm.

3. The flow cell component for a fluorescence detector of a liquid chromatograph according to claim 1, wherein the quadrangular prism core component (2) is manufactured by a high precision and high flatness splicing process, ensuring that four quartz glasses are right angled two by two and withstand a pressure of at least 2MPa without coming apart.

4. The flow cell element for a fluorescence detector of liquid chromatograph according to claim 1, wherein the exit light-shielding slit baffle (11) has a central slit width of 1.8 mm.

5. The flow cell element for fluorescence detectors of liquid chromatographs according to claim 1, characterized in that the support fixing plate (12) has a rectangular hole 15 x 12mm in the center.

6. The flow cell component for a fluorescence detector of a liquid chromatograph according to claim 1, wherein the flow cell input end flow guide head (7) and the flow cell output end flow guide head (8) are made of PEEK and have a central opening of 0.3 mm.

7. The flow cell element for a fluorescence detector of a liquid chromatograph according to claim 1, wherein the quadrangular prism-shaped projections (14) are prism-shaped having a cross-sectional side length of 1.76mm and a length of 0.7 mm; the center is processed into a bell mouth shape with the caliber of 1.6 mm.

8. The flow cell component for a fluorescence detector of a liquid chromatograph according to claim 1, wherein the flow cell input end flow guide head (7) and the flow cell output end flow guide head (8) are respectively fixed on the upper and lower sides of the flow cell C-shaped outer support (6) through end position screws (10), and the middle of the end position screws (10) and the flow guide heads are sealed by using sealing compression springs (9).

9. Flow cell component for a fluorescence detector of a liquid chromatograph according to claim 1, characterized in that it is mounted to the fluorescence detector by means of a mounting plate (13).

10. Flow cell component for a fluorescence detector of a liquid chromatograph according to claim 1, characterized in that the bell mouth of the quadrangular prism shaped protrusions (14) enters the central cavity of the quadrangular prism core component (2) by 0.5 mm.

Technical Field

The invention belongs to the technical field of liquid chromatography, and relates to a detection component for liquid chromatography. And more particularly to a flow cell component of a detector for detecting the intensity of fluorescence generated by photoluminescence in a liquid chromatography system.

Technical Field

Liquid chromatography has been developed for many years, and the corresponding technology is more and more mature, and has become the basic configuration of organic detection laboratories. In the general detection of liquid chromatography, the most commonly used is an absorption type detector such as an ultraviolet detector or the like, and the second is an absorption-emission type detector such as a fluorescence detector. With the highlighting of food safety and other problems, detection methods using fluorescence detectors as standard equipment are increasing. The flow cell is used as a core component of the fluorescence detector, and the quality of the flow cell directly influences the sensitivity and the detection limit of the detector.

When the fluorescence detector works, a beam of exciting light irradiates a component to be detected in the flow cell, the component to be detected enters an excited state immediately after absorbing the light energy of the exciting light, molecules in the excited state are extremely unstable, and are immediately de-excited to emit emitted light with a wavelength longer than that of the exciting light, namely fluorescence. The qualitative and quantitative analysis of the components to be detected is realized by measuring the fluorescence intensity generated by the components to be detected.

After the solution is excited by the excitation light, fluorescence can be observed in various directions of the solution, but since a part of the energy of the excitation light is directly transmitted, it is not appropriate to observe fluorescence in the direction of the transmitted light. Typically in a direction perpendicular to the excitation light. For example, a known apparatus is structured as follows: four pieces of quartz glass are spliced to form a hollow quadrangular prism. Two sides of the column body are sealed by two PEEK materials with holes. The exterior is fastened with stainless steel material. The column body is provided with a slit with a certain width in the direction of 90 degrees of incident light for filtering certain stray light. The component to be measured is carried by the mobile phase and enters the hollow quadrangular prism inner cavity. When the exciting light irradiates the component to be detected in the column, the component to be detected is excited to generate fluorescence. The intensity of the generated fluorescence is measured by a special photoelectric conversion device, and then the analysis and detection are carried out. Because the generated fluorescence is extremely weak in intensity, a particularly sensitive fluorescence detection device is required, and a high-sensitivity photomultiplier is generally adopted. Because the fluorescence detector is used as a detection device of a liquid chromatography system, the structure of the flow cell needs to have small influence on each substance separated by a chromatographic column, cannot generate adverse effects such as peak broadening and tailing on a detected component, and simultaneously needs to have certain constraint capacity on the dissipation of excited fluorescence, and in addition, all materials cannot generate fluorescence. The flow cell has dead angles on fluid in the transition between the hollow quadrangular prism made of quartz glass and the sealing material, so that adverse factors such as difficult replacement of sample residue, difficult removal of bubbles, broadening of peak shape, peak tailing and the like are easily caused, and meanwhile, weak fluorescence cannot be well gathered in the constraint of fluorescence dissipation, so that the sensitivity is low.

Disclosure of Invention

The present invention is directed to eliminating the disadvantages of the related devices and techniques described above. It is therefore an object of the present invention to provide a flow cell member for a fluorescence detector for liquid chromatography. It has excellent sensitivity, lower detection limit, less influence on the peak shape of the liquid chromatographic component, and easier elimination of bubbles.

In order to achieve the above object, the present invention provides a flow cell unit for a fluorescence detector of a liquid chromatograph, the unit comprising: a quadrangular prism core body component and a flow cell frame component.

In the invention, all the quadrangular prism core body components are made of four pieces of non-fluorescent high-transmittance quartz glass materials, and the section of a central cavity is 1.75mm by 1.75 mm.

In the invention, the outer walls of two adjacent glass surfaces of the glass quadrangular prism core body component are coated with high-reflection mirror coatings, and the mirror surfaces face inwards.

In the invention, when the glass quadrangular core body component is installed, two surfaces without the reflection coating are positioned in the light path of incident light and emergent light and are vertical to the light path.

In the present invention, the flow cell frame member includes: the device comprises a C-shaped inner support, a C-shaped outer support, a flow cell input end flow guide head, a flow cell output end flow guide head, a sealing pressure spring, an end position screw, a flow cell emergent light shading slit baffle, a support fixing piece and a mounting plate.

In the invention, the width of the central slit of the emergent light shading slit baffle of the flow cell is 1.8 mm. Fixed on the opening surface of the C-shaped inner support of the flow cell, and the center of the slit is superposed with the center of the fluorescent emergent light projection surface of the core body.

In the invention, the center of the support fixing sheet is provided with a 15 × 12mm rectangular hole which can be used for expanding and installing the optical filter.

In the invention, the flow guide head at the input end of the flow cell is made of PEEK, the center of the flow guide head is provided with a hole of 0.3mm, the tail end of the flow guide head is provided with a convex part, and the convex part is a prism with the side length of the section of 1.76mm and the length of 0.7 mm. The center is processed into a bell mouth shape with the caliber of 1.6 mm. When installed, the protrusion needs to enter the cavity port of the core body.

In the invention, the flow guide head at the output end of the flow cell is made of PEEK, the center of the flow guide head is provided with a hole of 0.3mm, the tail end of the flow guide head is provided with a convex part, and the convex part is a prism with the side length of the section of 1.76mm and the length of 0.7 mm. The center is processed into a bell mouth shape with the caliber of 1.6 mm. When installed, the protrusion needs to enter the cavity port of the core body.

In the invention, the end position screw can fix the flow guide end head on the C-shaped outer bracket of the flow cell, and the middle of the end position screw and the flow guide end head is sealed by using a sealing pressure spring.

In the present invention, the mounting plate is used to mount the flow cell to the fluorescence detector.

The device of the invention can not be used independently and needs to be arranged on a fluorescence detector, the end position screw for fixing the input diversion end of the flow cell is positioned below, the end position screw for fixing the output diversion end of the flow cell is positioned above, and the device is connected through a special liquid chromatogram mobile phase pipeline and a joint. In the working process, bubbles inevitably enter the flow cell, and because the bubbles are light, the bubbles in the system enter the flow cell and then are discharged along the way, and are easy to discharge. In addition, the input and output flow guide end of the flow cell adopts a bell mouth design, a sample enters the inner cavity of the core body of the quadrangular hollow column of the flow cell with the thickness of 1.75mm from a pipeline with the thickness of 0.3mm, and through the circulation and guide expansion of the flow guide port, dead volume hardly exists, and the flow cell can play a good role in inhibiting the adverse phenomena of peak broadening, peak tailing and the like frequently occurring in liquid chromatography.

The invention has the beneficial effects that:

(1) the flow cell component has a simple structure, and the sample enters the inner cavity of the core body of the quadrangular hollow column of the flow cell with the diameter of 1.6mm from a pipeline with the diameter of 0.3mm by using the circulation and guide expansion of the input and output flow guide end of the flow cell, so that the phenomenon that dead angles are formed at stagnation points of the fluid due to sudden change of the pipe diameter is avoided, the sample is thoroughly washed without residues, the dead volume is controlled to be minimum, and the flow cell component can play a good role in inhibiting adverse phenomena such as peak broadening, peak tailing and ghost peak interference.

(2) And a low-level inlet and high-level outlet flow mode is adopted, so that the air bubbles can be conveniently discharged, and the influence of the air bubbles on analysis is reduced.

(3) The four-edge hollow column core body component adopts a mirror surface coating design, so that the energy of an exciting light beam is effectively concentrated, and a measured object in the flow cell can absorb more light energy and generate more fluorescence. The generated fluorescence is very weak, and the emitted light can be effectively restrained by adopting the mirror surface coating design, so that the emitted light can be detected. The sensitivity of the system is effectively improved.

(4) The mounting tabs may be extended with color filters to filter out certain wavelengths of light that are not effective or interfering with particular needs.

Drawings

FIG. 1 is a cross-sectional view of a flow cell component for a fluorescence detector of a liquid chromatograph in accordance with the present invention.

Fig. 2 is a front view of a flow cell component for a fluorescence detector of a liquid chromatograph according to the present invention.

FIG. 3 is a schematic view of a high-reflective mirror coating according to the present invention.

Fig. 4a and 4b are schematic diagrams illustrating the effect of the flow cell component for the fluorescence detector of the liquid chromatograph according to the present invention.

Fig. 5 is a perspective view of a flow cell component for a fluorescence detector of a liquid chromatograph according to the present invention.

In fig. 1-5:

1-flow cell for fluorescence detector

2-glass quadrangular hollow column core body component

3-flow cell frame member

4-high reflection mirror coating

C-shaped inner support of 5-flow cell

C-shaped outer support of 6-flow cell

7-flow cell input end flow guide head

8-flow cell output end flow guide head

9-sealing pressure spring

10-end position screw

11-emergent light shading slit baffle

12-bracket fixing sheet

13-mounting plate

14-flow guiding head end bulge

Detailed Description

The present invention will be further described with reference to the following examples and the accompanying drawings. The procedures, conditions, test methods and the like for carrying out the present invention are general knowledge and common general knowledge in the art except for the contents specifically mentioned below, and the present invention is not particularly limited.

The invention discloses a flow cell component for a fluorescence detector of a liquid chromatograph, which comprises a quadrangular prism core component and a flow cell frame component. When the component to be detected enters the glass core body of the flow cell, under the irradiation of the exciting light, the component to be detected enters the excited state immediately after absorbing the light energy of the exciting light, and the molecule in the excited state is extremely unstable, and immediately excites and emits the emitting light with the wavelength longer than that of the exciting light, namely fluorescence. The emitted fluorescence can be transmitted to all directions, the outer walls of two adjacent glasses in the glass core body of the flow cell are coated with high-reflection coatings, the passing incident light and the generated fluorescence are bundled to a certain extent, and the fluorescence intensity generated by the component to be detected is measured in the direction of 90 degrees of the incident light, so that the qualitative and quantitative analysis of the component to be detected is realized. The invention designs the transition interface of the tested component entering the glass core body from the pipeline for the common liquid chromatogram by emphasis, so that the invention can achieve or even better than the detection effect of foreign like products in the aspects of effectively reducing peak broadening, peak tailing, eliminating ghost peaks and the like, and has simple processing and convenient installation. Can be widely applied to the fields of food safety, environmental detection, scientific research and the like.

Specifically, the flow cell component for a fluorescence detector of a liquid chromatograph mainly comprises: a glass quadrangular hollow column core body component and a flow cell frame component.

The core body component of the glass quadrangular hollow column is made of non-fluorescent high-transmittance quartz glass.

The mode of forming the quadrangular hollow column core body component is formed by splicing four pieces of quartz glass through special glass by adopting a high-precision high-flatness splicing process, and a quadrangular hollow column structure with the outer side length of 5mm and the inner cavity side length of 1.75mm and the height of 7mm is formed. The four pieces of quartz glass form right angles pairwise and bear the pressure of at least 2MPa without separation, thereby ensuring that the incident light path is vertical to the emission light path so as to reduce the interference of the excitation light on the emission light

Wherein, two adjacent outer walls of the quartz glass forming the four-edge hollow column core body component are coated with high-reflection mirror coatings. The other two blocks remain in high transmittance mode.

Wherein, constitute the circulation pond frame part and include: the flow cell comprises a flow cell C-shaped inner support, a flow cell C-shaped outer support, a flow cell input end flow guide head, a flow cell output end flow guide head, a sealing pressure spring, an end position screw, a flow cell emergent light shading slit baffle, a support fixing piece and a mounting plate.

Wherein, the emergent light shading slit baffle of the flow cell is fixed at the opening of the C-shaped inner support of the flow cell.

Wherein, the slit width at the center of the baffle plate of the emergent light shading slit of the flow cell is not more than 2mm, preferably 1.8mm

The center of the slit on the baffle plate of the emergent light shading slit of the flow cell is superposed with the center of the fluorescent emergent light projection plane of the quartz core body.

The tail part of the flow guide head at the input end of the flow cell is provided with a quadrangular prism with the section side length of 1.76mm and the length of 0.7mm, the center of the quadrangular prism is provided with a bell mouth with the caliber of 1.6mm, and the small end of the bell mouth is communicated with a 0.3mm pipeline at the center of the flow guide head main body.

Wherein, the design mode of the bell mouth at the tail part of the flow guide head at the output end of the flow cell is the same as that of the flow guide head at the input end. The length of the bell mouth is not more than 1.0mm, preferably 0.7mm

Wherein, the flow-guiding heads at the input end and the output end of the flow cell are preferably made of black PEEK material

In order to ensure that the input end and the output end of the flow cell can be inserted into the quartz core body cavity and play a role in sealing, the outer side length of the quadrangular prism convex part at the tail part of the flow guide head cannot be smaller than the inner side length of the quartz core body cavity, and meanwhile, the outer side length of the quadrangular prism convex part cannot be too large so as not to be installed or break the quartz core body, so that the outer side length of the quadrangular prism convex part is slightly larger than the inner side length of the quartz core body cavity by about 0.01 mm.

Wherein, the caliber of the bellmouth protruded at the tail part of the flow guide head at the input end and the output end of the flow cell cannot be too small, is generally not less than 1.3mm, and is preferably 1.6mm, so as to reduce the dead volume generated by the wall thickness effect

The flow cell comprises a flow cell C-shaped inner support, a flow cell C-shaped outer support, a flow cell emergent light shading slit baffle, a support fixing piece and an installation plate, wherein black paint is coated or sprayed on the support fixing piece and the installation plate, and the used paint or the sprayed paint cannot generate fluorescence.

Example 1

FIG. 1 is a schematic diagram of the basic structure of an embodiment of a flow cell for a fluorescence detector of a liquid chromatography system according to the present invention.

The fluorescence detector flow cell (1) in this example is composed of two parts: a glass quadrangular hollow column core body component (glass core body for short) (2) and a flow cell frame component (3). The glass core body part is made of four pieces of non-fluorescent high-transmittance quartz glass by a special glass welding technology, wherein the outer walls of two adjacent pieces of glass are coated with high-reflection mirror coatings (4) mainly used for generating and measuring fluorescence. The flow cell frame member comprises: the flow cell is characterized by comprising a flow cell C-shaped inner support (5), a flow cell C-shaped outer support (6), a flow cell input end flow guide head (7), a flow cell output end flow guide head (8), a sealing pressure spring (9), an end position screw (10), a flow cell emergent light shading slit baffle (11), a support fixing piece (12) and a mounting plate (13). The flow cell holder assembly is used primarily for fixing the glass core and the flow guide of the sample solution and for fixing to a fluorescence detector. Wherein, the flow cell input end flow guide head and the output end flow guide head are made of PEEK material, one section is connected to the end position screw, and the other section is connected to the glass core body. The central bore diameter of the flow guide head is 0.3mm, and a quadrangular-prism-shaped bulge (14) with the section side length of 1.76mm and the length of 0.7mm is processed at the part of the flow guide head connected with the glass core body. The outlet of the bulge is processed into a bell mouth shape with the caliber of 1.6mm and is communicated with a channel with the center of 0.3 mm.

The invention can not be used independently and needs to be installed on a fluorescence detector for use. When the device is used, the component to be measured enters the glass core body from the pipeline connected with the input end position screw under the carrying of the mobile phase, and meanwhile, a beam of exciting light is absorbed into the inner cavity of the glass core body from the high-transmittance glass without the emission mirror surface coating of the glass core body. The component to be measured enters the excited state immediately after absorbing the energy of the excitation light, and the molecule in the excited state is extremely unstable, immediately de-excites and emits emission light having a longer wavelength than the excitation light, which is fluorescence and is generally referred to as emission light. The fluorescence generated in the flow cell is very weak and extremely instantaneous, and a photomultiplier tube device is installed in a common fluorescence detector and can be used for detecting the extremely weak and extremely instantaneous fluorescence and displaying the fluorescence in the form of an electric signal. The fluorescence detector displays the fluorescence phenomenon occurring in the detector on a screen by capturing the extreme instantaneous current changes of the multiplier tube. Thereby realizing fluorescence detection. Because the structure of the flow cell has great influence on the shape of a measured object in the flow cell, if the structure of the flow cell causes the phenomenon of stagnation point (15) or inflection point (16) of fluid, the peak will be widened, deformed, trailing and the like, and the final detection will be greatly influenced.

Although the foregoing description has been made of the embodiments of the present invention, the present invention is not limited to the above-described embodiments, and various changes may be made without departing from the scope and spirit of the present invention as set forth in the appended claims, such as the size of the glass core body, the shape of the flow-guiding head at the input end and the output end of the flow cell, the shape and size of the end protrusion, and the like, without any particular limitation on the size and shape. The length, width and shape of the slit on the baffle plate of the light-shading slit of the emergent light of the flow cell are not limited to specific specifications. The structure provided by the invention can avoid the phenomena of stagnation points and inflection points of the fluid after the liquid enters the flow cell, and reduce the dead volume, thereby better realizing the fluorescence detection on the liquid chromatogram.

The present invention is not limited to the above embodiments, and variations and advantages which can be conceived by those skilled in the art are included in the present invention without departing from the spirit and scope of the inventive concept, and the scope of the appended claims is defined as follows.