A fluorescence detection system and method

Abstract

The present invention discloses a fluorescence detection system and method. Fluorescence is emitted by a xenon lamp, and after being condensed by a concave mirror, it sequentially passes through a first reflector, a first grating, and a beam splitter. One part reaches a silicon photocell detector to detect whether the light source is stable, and the other part enters a detection cell, irradiates the sample in the cell and then exits, and then passes through a second grating and reaches a photomultiplier tube to obtain a fluorescence detection signal for detecting substances. By online real-time monitoring of the stability of the light source, unstable factors of the light source can be eliminated in a timely manner to ensure the accuracy of fluorescence detection. Through an integrated detection cell, positioning and replacement are convenient, and it can be applicable to both on-column and capillary detection cells simultaneously.

Description

Technical Field

[0001] The present invention belongs to the field of fluorescence detection technology, and particularly relates to a fluorescence detection system and method. Background Art

[0002] A fluorescence detector mainly emits excitation light through a light source. After irradiating a fluorescent substance, the fluorescence emitted by the fluorescent substance is turned into monochromatic fluorescence by a monochromator and then irradiated onto a sample. A photomultiplier tube amplifies the received photocurrent and transmits it to a recorder to complete the detection. When in use, the stability of the light source will directly affect the accuracy of the detection result. However, existing fluorescence detectors do not have measures for online detecting the stability of the light source and cannot timely detect light source abnormalities caused by insufficient power supply or problems with the xenon lamp itself. Moreover, the detection cell is usually installed inside the chassis and fixed on the bottom plate, so replacement requires the entire machine to be disassembled, which is very inconvenient. In addition, existing gratings are only equipped with one zero-position sensor. After each startup, the grating first rotates to the zero-position and then starts to rotate to the target position according to the setting to obtain the required wavelength. However, there is no detection means for whether the grating actually rotates accurately in place. Once there are command interferences or communication problems, the effectiveness of fluorescence detection cannot be guaranteed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a fluorescence detection system and method that can online and real-time monitor the stability of the light source.

[0004] To solve the above technical problem, the present invention adopts the following technical solutions:

[0005] On the one hand, a fluorescence detection system includes:

[0006] A light source, including a xenon lamp, for emitting fluorescence;

[0007] A condenser concave mirror for condensing and reflecting the fluorescence;

[0008] A first light inlet slit and a first reflector, the fluorescence reflected by the condenser concave mirror passes through the first light inlet slit and is then reflected by the first reflector;

[0009] A first grating and a first light outlet slit, the first grating is used for re-reflecting the fluorescence reflected by the first reflector according to a set wavelength and passing through the first light outlet slit;

[0010] A monitoring chamber, including a beam splitter and a silicon photocell detector, the beam splitter is used for reflecting a part of the fluorescence passing through the first light outlet slit to the silicon photocell detector, and the silicon photocell detector is used to detect whether the light source is stable;

[0011] A detection cell, the other part of the fluorescence passes through the beam splitter to the detection cell, irradiates the sample to be measured in the cell and then exits;

[0012] The second light incident slit and the second grating, the emitted fluorescence passes through the second light incident slit and reaches the second grating, and is reflected by the second grating according to the set wavelength;

[0013] The second light output slit and the photomultiplier tube, the reflected fluorescence passes through the second light output slit to the photomultiplier tube to obtain a detection signal.

[0014] The light source further includes a light source box, a xenon lamp holder is provided in the light source box, the light source box has a top plate, a window for loading the xenon lamp is provided on the top plate, and there is also a pair of window baffles above the top plate. Each of the two baffles is provided with a semi-circular hole, and by combining, a clamping hole for fixing the upper end of the xenon lamp is formed, and a waist-shaped hole for adjusting the fixing position on the top plate is also provided on the baffle.

[0015] The condenser concave mirror is provided on the lens bracket at one end of the light source box through an elastic support mechanism. An adjustment component for adjusting the deflection of the condenser mirror is also provided on the lens bracket. The adjustment component includes symmetrically arranged adjustment bolts and compression springs. The tail of the adjustment bolt passes through the lens bracket and abuts against the back of the condenser concave mirror, and the compression spring abuts between the lens bracket and the back of the condenser concave mirror.

[0016] The condenser concave mirror includes a mirror shell, a lens and a snap ring. The front end of the mirror shell is open, and the outer edge has several bolt holes. The lens is adapted to the mirror shell. The front end mirror surface of the lens is an inwardly concave aspherical surface. The lens is arranged in the mirror shell through the open end, and the snap ring is arranged in front of the lens, and the lens is fixed on the mirror shell by bolts passing through the corresponding bolt holes.

[0017] The lens is made of aluminum alloy material, and a protective film is plated on the front end mirror surface.

[0018] The first and second gratings both include a grating body, a rotating base for installing the grating body, a driving device for driving the rotating base to rotate, a first induction rod synchronously rotating with the rotating base, a zero position sensor for detecting the first induction rod, and further include a target position sensor provided on one side of the zero position sensor and used for detecting the first induction rod, a second induction rod rotating together with the driving device, and a calibration sensor for detecting the second induction rod. The driving device includes a driving motor connected below the rotating base and a speed reducer connected below the driving motor. The second induction rod is connected to the main shaft of the speed reducer.

[0019] The detection cell includes a flow cell rack, a flow cell provided in the flow cell rack, and flow cell compression heads fixed at both ends of the flow cell for fixing the flow cell. The flow cell rack has a light incident hole for the fluorescence to enter and irradiate on the flow cell with the substance to be measured, and a light output hole for the fluorescence to exit. The flow cell is a liquid phase column flow cell or a capillary flow cell.

[0020] The detection system further includes a detection light-shielding chamber, and an installation window is provided on the side of the detection light-shielding chamber; the detection slot further includes a connecting partition block provided at one end of the flow cell rack, and a fixing plate is further provided at one end of the connecting partition plate. The connecting partition block and the flow cell rack are installed in the detection light-shielding chamber through the installation window and fixed on the outer wall of the detection light-shielding chamber at the installation window through the fixing plate.

[0021] On the other hand, a detection method for a fluorescence detection system includes the following steps:

[0022] A. Emitting fluorescence from a xenon lamp to a condenser concave mirror;

[0023] B. Condensing and reflecting the fluorescence through the condenser concave mirror;

[0024] C. The reflected fluorescence passes through the first light inlet slit and then reaches the first reflector, is reflected by the first reflector to the first grating, and a spectral band with a set wavelength is reflected by the first grating;

[0025] D. The spectral band passes through the first light outlet slit and then enters the monitoring chamber to a beam splitter. A part of the fluorescence is reflected by the beam splitter to a silicon photocell detector, and the silicon photocell detector is used to detect whether the light source is stable;

[0026] E. The other part of the light passes through the beam splitter and enters the detection slot, irradiates the sample in the slot and then exits;

[0027] F. The emitted fluorescence passes through the second light inlet slit to the second grating, and a spectral band with a set wavelength is reflected by the second grating;

[0028] G. The spectral band passes through the second light outlet slit to a photomultiplier tube to obtain a detection signal.

[0029] In step C or F, the following grating control steps are further included:

[0030] H. The grating is driven by a driving motor to rotate until the first induction rod is detected by a zero position sensor and stops at the zero position;

[0031] I. Then driving the grating to rotate towards the target position according to an instruction;

[0032] J. When rotating until the first induction rod is detected by the target position sensor and at the same time, the calibration sensor also obtains the signal of the second induction rod, and the two signals can match, then stop rotating to indicate accurate positioning and be able to reflect a spectral band with a set wavelength.

[0033] Adopting a fluorescence detection system and method of the present invention, fluorescence is emitted by a xenon lamp. After being condensed by a concave mirror, it successively passes through a first reflector, a first grating, and a beam splitter. One part is detected by a silicon photocell detector to check whether the light source is stable, and the other part enters the detection cell, irradiates the sample in the cell and then exits. After passing through a second grating, it reaches a photomultiplier tube to obtain the detection signal of the substance to be measured. By online real-time detecting the stability of the light source, the accuracy of fluorescence detection can be ensured. Through the integrated detection cell, positioning and replacement are convenient, and it can be applicable to both on-column or capillary detection cells simultaneously. The condensing concave mirror can achieve fine adjustment of the up, down, left, and right deflection angles of the condensing mirror through an elastic support mechanism and an adjustment component. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be described in detail below with reference to the drawings and specific embodiments:

[0035] Figure 1 is a schematic structural diagram of one perspective of the fluorescence detection system of the present invention;

[0036] Figure 2 is a schematic structural diagram of another perspective of the fluorescence detection system of the present invention;

[0037] Figure 3 is a schematic structural diagram of the light source of the present invention;

[0038] Figure 4 is a perspective view of the condensing concave mirror of the present invention installed in the light source box;

[0039] Figure 5 is at Figure 4 Based on this, a three-dimensional structural diagram with the lens holder hidden

[0040] Figure 6 is a three-dimensional schematic diagram of the condensing concave mirror of the present invention;

[0041] Figure 7 is a cross-sectional view of the installation structure of the condensing concave mirror of the present invention;

[0042] Figure 8 is an enlarged schematic diagram of the elastic support mechanism of the present invention;

[0043] Figure 9 is an installation schematic diagram of the grating of the present invention;

[0044] Figure 10 is a schematic structural diagram of the grating of the present invention;

[0045] Figure 11 is an installation schematic diagram of the zero position sensor and the target position sensor of the present invention;

[0046] Figure 12 is a schematic diagram of the installation position of the monitoring chamber of the present invention;

[0047] Figure 13 It is a schematic structural diagram of the monitoring room of the present invention;

[0048] Figure 14 It is a schematic structural diagram of the monitoring room and the detection tank of the present invention from one perspective;

[0049] Figure 15 It is a schematic structural diagram of the interior of the monitoring room of the present invention;

[0050] Figure 16 It is a schematic structural diagram of the monitoring room and the detection tank of the present invention from another perspective;

[0051] Figure 17 It is a schematic structural diagram of the installation structure of the detection tank of the present invention;

[0052] Figure 18 It is a schematic structural diagram of the fixing plate of the present invention;

[0053] Figure 19 It is a schematic structural diagram of the installation window of the present invention;

[0054] Figure 20 It is a schematic structural diagram of the connection spacer and the flow cell assembly of the present invention;

[0055] Figure 21 It is a schematic structural diagram of the flow cell assembly of the present invention;

[0056] Figure 22 It is a schematic structural diagram of the light inlet and outlet holes of the flow cell rack of the present invention;

[0057] Figure 23 It is a schematic structural diagram of the liquid phase column flow cell of the present invention;

[0058] Figure 24 It is a schematic connection diagram of the flow cell compression head and the inlet and outlet pipes of the present invention;

[0059] Figure 25 It is a schematic diagram of the installation structure of the detection tank of the capillary of the present invention;

[0060] Figure 26 It is a schematic structural diagram of the flow cell of the capillary of the present invention;

[0061] Figure 27 It is a schematic structural diagram of the outlet baffle of the present invention;

[0062] Figure 28 It is a schematic structural diagram of the connection spacer of the present invention;

[0063] Figure 29 It is a schematic structural diagram of the second grating and the second light outlet slit of the present invention;

[0064] Figure 30 This is the optical principle of the present invention. Specific embodiments

[0065] A fluorescence detection system of the present invention is as Figure 1 - Figure 2 shown, and mainly includes a light source 1, a condenser concave mirror 2, a first light inlet slit 3, a first reflector 4, a first grating 5, a first light outlet slit 6, a monitoring chamber 8, a detection tank 9, a second light inlet slit 10, a second grating 11, a second light outlet slit 12 (see Figure 23 ), and a photomultiplier tube 13. Among them,

[0066] As Figure 3 shown, the light source 1 includes a xenon lamp 14 for emitting fluorescence. The light source 1 further includes a light source box. The light source box mainly includes a bottom plate 101, a top plate 105, two side plates 102 ( Figure 1 , 2 the left side plate in which is hidden, and only the right side plate is shown), and a front plate 103, etc., forming a box-shaped structure. A xenon lamp socket 106 is provided on the bottom plate 101 inside the box. The top plate 105 has a circular window 109 for the xenon lamp 14 to be inserted. The xenon lamp 14 can extend through the window 109 and is installed on the xenon lamp socket 106 by means of a thread at the bottom, while the upper end of the xenon lamp 14 is exposed outside the window 109. Above the top plate 105, there is also a pair of circular window baffles 107. Each of the two baffles 107 is provided with a semi-circular hole. By combining, a clamping hole for fixing the upper end of the xenon lamp 14 is formed. Moreover, the baffle 107 is also provided with a waist-shaped hole 108 for adjusting the position on the top plate 105, and the position can be adjusted accordingly on the top plate according to different specifications of the xenon lamp 14 to meet the installation and positioning requirements of xenon lamps 14 of different model sizes.

[0067] Therefore, during use, loosen the bolt (not shown in the figure) on the waist-shaped hole 108, move the circular window baffles 107 to both sides to expose the window 109, select the xenon lamp 14 of the required specification, extend it into the light source box through the window and install it on the xenon lamp socket 106, and then move the two circular window baffles 107 relatively so that the clamping hole just clamps and positions the exposed end of the xenon lamp 14, playing the role of shading the window and fixing the xenon lamp 14, and then lock the bolt on the waist-shaped hole 108 to fix it to the top plate 105.

[0068] In addition, a light outlet round hole 110 is opened on the front plate 103, and a conical light-shielding cylinder 111 is provided at the front end of the front plate 103. The diameter of the end of the light-shielding cylinder 111 is the same as that of the light outlet round hole 110 of the front plate 103 and is connected and communicated, and the diameter gradually becomes smaller from the back to the front. The light emitted by the xenon lamp 14 is reflected by the condenser concave mirror 2 provided at the rear of the light source box 13 and then exits the light source box from the light outlet round hole 110 and passes through the light-shielding cylinder 1111 into the subsequent detection structure of the fluorescence detector 1.

[0069] As Figure 4 - Figure 8As shown in the figure, the condenser concave mirror 2 is arranged at the rear of the light source box 1 to condense and reflect the fluorescence emitted by the xenon lamp. It includes a lens 21. The lens 21 can be made of aluminum alloy material, and preferably processed from super-hard aluminum alloy, etc. The front mirror surface of it is an inwardly concave aspherical surface, and a protective film is plated on the surface. By using the lens 21 of this material, it can be cut and polished by a numerical control machine tool, which is convenient for processing, can reduce processes such as aluminizing molds, and the material cost is only about one-tenth of the traditional quartz material plated with a double-layer film, with stable performance and long service life.

[0070] A mirror body support 22 is arranged on the back side of the condenser concave mirror 2. The condenser concave mirror 2 further includes a cylindrical mirror shell 23 and a snap ring 24. The front end of the mirror shell 23 is an open mouth, and the outer edge has several axial bolt holes 25 protruding. The lens 21 is adapted to the mirror shell 23. The lens 21 is arranged in the mirror shell 23 through the open mouth. The snap ring 24 is arranged in front of the lens 21, and the edge of the light-condensing surface of the lens 21 is fixed on the mirror shell 23 by bolts 26 passing through the corresponding bolt holes 25. The whole condenser concave mirror 2 is arranged on the mirror body support 22 through an elastic support mechanism. There is also a cavity 27 protruding backward in the middle of the rear part of the mirror shell 23. The elastic support mechanism is arranged in the cavity 27, specifically including a support spring 281 and a support bolt 282. An axial stepped hole 283 is opened in the center of the cavity 27, and there is also an annular groove 284 for limiting the support spring 281 outside the stepped hole 283. One end of the support spring 281 abuts against the lens 21, and the other end is arranged in the annular groove 284 and abuts against the rear wall of the cavity 27. A rocking ring 285 with a conical inner hole is arranged in the stepped hole 283. One end of the support bolt 282 is a ball head arranged in the cavity 27 and cooperates with the conical inner hole of the rocking ring 285. The other end passes through the rocking ring 285, the rear wall of the cavity 27, and the mirror body support 22 in sequence, and is fastened to the mirror body support 22 through a nut 286. Through this elastic support mechanism, the support and positioning of the lens 21 can be realized, and the floating setting required for the deflection adjustment of the mirror shell 23 can also be satisfied.

[0071] Two groups of adjusting components for adjusting the deflection of the condenser concave mirror 2 are also arranged on the mirror body support 22. Each group of adjusting components includes symmetrically arranged adjusting bolts 291 and compression springs 292, that is, one group is arranged on the left and right sides of the support bolt 282, and one group is arranged on the upper and lower sides. The tail of the adjusting bolt 291 passes through the mirror body support 22 and abuts against the back surface of the mirror shell 23 of the condenser concave mirror 2, and the compression spring 292 abuts between the mirror body support 22 and the back surface of the condenser concave mirror 2. In addition, there are two guide posts 293 integrated with the mirror shell 23 and corresponding to the compression springs 292 on the rear end surface of the mirror shell 23, and the compression springs 292 are respectively sleeved on the corresponding guide posts 293.

[0072] Thus, when it is necessary to adjust the deflection angle of the condenser concave mirror 2, taking the left and right angle adjustment as an example, only by pushing the mirror housing 23 forward through the left adjusting bolt 291 can the whole condenser concave mirror 2 be driven to deflect to the right side, and when the adjusting bolt 291 is retracted backward, it will deflect to the left under the action of the compression spring 292 on the right side, so that the fluorescence finally condensed and reflected by the condenser concave mirror 2 can pass through the slit. The up and down angle adjustment is the same.

[0073] The first light inlet slit 3 is arranged in front of the conical light-shielding cylinder 111. The first reflector 4 is arranged on the front side of the first light inlet slit 3. The fluorescence reflected by the condenser concave mirror 2 passes forward through the conical light-shielding cylinder 111, the first light inlet slit 3 to the first reflector 4 in sequence, and is reflected by the first reflector 4 to the first grating 5.

[0074] As Figure 9 - Figure 11 shown, the first grating 5 is arranged on the diagonal side of the first reflector 4, and is used to reflect the fluorescence reflected by the first reflector 4 into the spectral band of the set wavelength. The first grating 5 includes a grating body 51, a rotating base 52 for installing the grating body 51, a driving device for driving the rotating base 52 to rotate, a first induction rod 54 synchronously rotating with the rotating base 52, and a zero position sensor 55 for detecting the first induction rod 54. The grating body 51 is installed on the rotating base 52. The driving device includes a driving motor 56 connected to the lower part of the rotating base 52 and a speed reducer 57 connected to the lower part of the driving motor 56. The rotating base 52 is driven to rotate by the driving motor 56, so that the grating body 51 and the first induction rod 54 rotate by corresponding angles. The grating further includes a target position sensor 58 arranged on one side of the zero position sensor 55 and used to detect the first induction rod 54, a second induction rod 59 horizontally connected to the main shaft of the speed reducer 57 and capable of rotating together with the main shaft 50 of the speed reducer 57, and a calibration sensor 53 arranged outside the speed reducer 57 and used to detect the second induction rod 59. The zero position sensor 55, the target position sensor 58, and the calibration sensor 53 can all adopt photoelectric switches.

[0075] The working principle of the grating is as follows: After each startup, the driving motor 56 will drive the grating to rotate until the first induction rod 54 is detected by the zero position sensor 55 and stops at the zero position, and then it can rotate to the target position according to the instruction. When the first induction rod 54 is detected by the target position sensor 58, the calibration sensor 53 should also obtain the signal of the second induction rod 59, and the two signals can match (the first induction rod 54 and the second induction rod 59 have corresponding speed ratios), which indicates that the grating rotates in place and can accurately reflect the spectral band of the set wavelength.

[0076] Due to the setting of the target position sensor 58 and the calibration sensor 53, the first and second sensing rods 54 and 59 can be detected respectively, and verified according to the two detection data, so that the rotation of the grating according to the instruction can be calibrated every time it is used, so as to ensure that a spectral band with accurate wavelength can be obtained every time.

[0077] As Figure 12 - Figure 16 shown, the first light outlet slit 6 is arranged at the rear side of the first reflector 4. The monitoring chamber 8 is arranged at the rear side of the first light outlet slit 6. The monitoring chamber 8 is enclosed by a light-shielding cover plate 7 to form a light-shielding chamber, and a light inlet window 71 and a light outlet window 72 are respectively arranged at its front side and rear side. Inside the monitoring chamber 8, there are a beam splitter 81, a first convex lens sleeve 82 and a silicon photocell detector 83. The beam splitter 81 is arranged at a certain deflection angle, and can pass part of the fluorescence emitted by the light source 1 for subsequent substance detection, and part of it is reflected to the first convex lens sleeve 82. The first convex lens sleeve 82 is arranged at the side of the beam splitter 81 to receive the emitted fluorescence of the beam splitter 81 and condense it; the silicon photocell detector 83 is arranged at the rear side of the first convex lens sleeve 82 to receive the condensed light of the first convex lens sleeve 82 to detect whether the energy intensity of the light source 11 is stable. The beam splitter 81 can be specifically designed to include a lens holder 811, a light passing window 812 opened on the lens holder 811, and a reflector 813 for shielding part of the light passing window 812. The reflector 813 usually shields the lower one-third of the light passing window 812.

[0078] When the fluorescence emitted by the light source 1 obtains a spectral band with a set wavelength through the first grating 5, it passes through the first light outlet slit 6 and then enters the monitoring chamber 8 through the light inlet window 71, and directly hits the beam splitter 81. Two-thirds of the fluorescence passes through the light passing window 82 through the beam splitter 81 and then is emitted through the light outlet window 72 to the subsequent detection tank 9 for fluorescence substance detection; while one-third of the fluorescence is reflected by the reflector of the beam splitter 81 to the first convex lens sleeve 82 and then to the silicon photocell detector 83, and the energy intensity of the light source 1 is detected in real time by the silicon photocell detector 83, so as to realize the on-line detection of the stability of the light source 1.

[0079] As Figure 17 - Figure 28 shown, a detection chamber 91 is arranged at the rear side of the light outlet window 72. The detection chamber 91 is a light-shielding chamber (including the surroundings and above) composed of several light-shielding plates. The detection chamber 91 has a light inlet round hole 914, a light outlet round hole 915 and an installation window 96 arranged in different directions. A second convex lens sleeve 92 is arranged between the light outlet window 72 and the light inlet round hole 914. The light inlet round hole 914 and the light outlet round hole 915 are arranged at 90° to each other (see Figure 14 ), and the installation window 96 is arranged at the opposite position of the light inlet round hole 914.

[0080] Inside the detection chamber 91, there is a detection tank body, which includes a fixed plate 94, a connecting partition block 95, and a flow cell assembly through which the substance to be detected flows in sequence. The fixed plate 94 is larger than the installation window 96 and is located on the outer wall of the light-shielding plate 5 at the installation window 96. The cross-section of the connecting partition block 95 and the flow cell assembly is smaller than the installation window 96 and can extend into the detection chamber 91 through the installation window 96. As Figure 3 - Figure 4 shown, the specific installation method of the fixed plate 94 can be to set screw holes 911 for connecting with the fixed plate 94 and positioning posts 913 that cooperate with the positioning holes 912 on the fixed plate 94 on the light-shielding plate with the installation window 96. The screw holes 911 are respectively arranged on the upper and lower sides of the installation window 96, and the positioning posts 913 are respectively arranged on the left and right sides of the installation window 96. The fixed plate 94 is first positioned through the positioning posts 913, and then fixed to the light-shielding plate by bolts passing through the screw holes 911.

[0081] The flow cell assembly mainly includes a flow cell frame 991, a flow cell arranged inside the flow cell frame 991, and flow cell compression heads 992 fixed at both ends of the flow cell to fix the flow cell. The flow cell frame 991 can be made of plastic material, while the flow cell compression heads 992 are made of metal material and are inserted into the flow cell frame 991 from the upper and lower ends in cooperation. The flow cell frame 991 has a light inlet hole 916 and a light outlet hole 917 that communicate with the light inlet round hole 914 and the light outlet round hole 915 respectively, that is, the light inlet hole 916 and the light outlet hole 917 are also arranged at a 90° angle to each other. There is also a second convex lens sleeve 93 between the light outlet hole 917 and the light outlet round hole 915. The flow cell assembly also includes a flow cell inlet baffle 918 and a flow cell pressing plate 919 respectively arranged on both sides of the flow cell frame 991. The flow cell inlet baffle 918 is provided with a light passing window 920 that communicates with the second convex lens sleeve 92 and the light inlet hole 916, and the flow cell pressing plate 919 is provided with a flow cell observation hole 921.

[0082] When a liquid phase column detection tank is selected, its flow cell is a liquid phase column flow cell, which includes a square quartz glass tube 922 arranged between two flow cell compression heads 992, a flow cell inlet pipe 923 that passes through the lower end into the flow cell compression head 992 at the lower end from the lower part, and a flow cell outlet pipe 924 that passes through the upper end into the flow cell compression head 992 at the upper end from the upper part. There is also a gasket 925 between the flow cell compression heads 992 at the upper and lower ends and the square quartz glass tube 922, and flow holes 926 that communicate with the square quartz glass tube 922 are provided on both the flow cell compression heads 992 and the gasket 925. The flow cell inlet and outlet pipes 923 and 924 are metal hard pipes and are respectively fixed to the corresponding flow cell compression heads 992. The other ends of the flow cell inlet and outlet pipes 923 and 924 can pass through the slot holes 928 opened on the connecting partition block 95 and pass through the fixed plate 94 from the installation window 96.

[0083] When the capillary detection cell is selected, compared with the liquid-phase column detection cell, the difference is only that: the flow cell is a capillary 927, and pipe connectors 929 are respectively provided on the upper and lower flow cell compression heads 992, and an observation window member 930 with an observation window and communicating with the light inlet hole 916 and the light outlet hole 917 is provided between the two flow cell compression heads 992. A capillary 927 passes through the two pipe connectors 929, the two flow cell compression heads 992, and the observation window member 930 after being sleeved with a protective sleeve 935 made of PEEK material, and the irradiated section of the capillary 927 located in the observation window member 930 is transparent and not sleeved with a protective sleeve 935, which is used for irradiating the analyte in the tube with fluorescence. The irradiated section can be made by sintering the capillary 927. By setting the protective sleeve 935, the pipe connector 929 can tightly fix the capillary 927 sleeved with the protective sleeve 935. The two ends of the flexible capillary 927 can also pass through the slot holes 928 of the connection spacer 95 and pass out of the fixing plate 94 through the installation window 96. The observation window communicates with the flow cell observation hole 921 on the flow cell pressing plate 919.

[0084] On one side of the flow cell holder 991 with the light outlet hole 917, an outlet baffle 931 is also connected. The outlet baffle 931 has a U-shaped structure and is connected to the flow cell holder 991 through bolts passing through the screw holes 932 to shield the two sides of the fluorescence coming out of the light outlet hole 917.

[0085] One end face of the connection spacer 95 also has screw holes 932 connected to the fixing plate 94, while the side face has a weight-reducing through hole 934. The slot holes 928 are opened on one side face of the connection spacer 95 and are fixed by pressing with a pressing plate 933.

[0086] Since the entire detection cell body is an integral structure, when installing or replacing the detection cell, only the disassembly and assembly of the installation window 96 and the fixing plate 94 are required to complete the replacement. At the same time, the liquid-phase column and the capillary 927 detection cell adopt the same size and structure, and no debugging is required during replacement, which can ensure the position matching between the second convex lens sleeve 92, the light inlet round hole 914, the flow cell, the second convex lens sleeve 93, and the light outlet round hole 915. It is not only simple and convenient but also expands the range of detected substances.

[0087] As Figure 29 shown, the fluorescence emitted from the light outlet round hole 915 passes through the second light inlet slit 10 and then irradiates onto the second grating 11. The structure and working principle of the second grating 11 are the same as those of the first grating 5, which can reflect the fluorescence into a spectral band of a set wavelength, and then irradiate onto the photomultiplier tube 13 after passing through the second light outlet slit 12 to obtain the detection signal of the analyte.

[0088] Combined Figure 30 shown, the detection method of the fluorescence detection system of the present invention includes the following steps:

[0089] A. Fluorescence is emitted from the xenon lamp 14 to the condenser concave mirror 2;

[0090] B. The condenser concave mirror 2 condenses and reflects the fluorescence;

[0091] C. The reflected fluorescence passes through the first light inlet slit 3 and then reaches the first reflector 4. It is reflected by the first reflector 4 to the first grating 5, and a spectral band of a set wavelength is reflected by the first grating 5;

[0092] D. The spectral band passes through the first light outlet slit 6 and then enters the monitoring chamber 8 to the beam splitter 81. A part of the fluorescence is reflected by the beam splitter 81 to the silicon photocell detector 83, and the silicon photocell detector 83 is used to detect whether the light source is stable;

[0093] E. The other part of the light passes through the beam splitter 81 and enters the detection cell 9, irradiates the sample in the cell and then exits;

[0094] F. The emitted fluorescence passes through the second light inlet slit 10 to the second grating 11, and a spectral band of a set wavelength is reflected by the second grating 11;

[0095] G. The spectral band passes through the second light outlet slit 12 to the photomultiplier tube 13 to obtain a detection signal.

[0096] In step C or F, the following grating control steps are further included:

[0097] H. The driving motor 56 drives the grating to rotate until the first sensing rod 54 is detected by the zero position sensor 55 and stops at the zero position;

[0098] I. Then the grating is driven to rotate towards the target position according to the instruction;

[0099] J. When the rotation reaches the point where the first sensing rod 54 is detected by the target position sensor 58, at the same time, the calibration sensor 53 also obtains the signal of the second sensing rod 59, and the two signals can match, then the rotation stops, indicating that it is in place accurately and can reflect a spectral band of a set wavelength.

[0100] However, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as it is within the scope of the essential spirit of the present invention, changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A fluorescence detection system, comprising: Light sources, including xenon lamps, to produce fluorescent light; A focusing concave mirror, used to focus and reflect the fluorescent light; A first light entrance slit and a first reflector, wherein the fluorescent light reflected by the focusing concave mirror passes through the first light entrance slit and is then reflected by the first reflector; a first grating and a first light exit slit, wherein the first grating is used to re-reflect the fluorescence reflected by the first reflector according to a set wavelength and pass through the first light exit slit; The monitoring room includes a beam splitter and a silicon photocell detector. The beam splitter is used to reflect a part of the fluorescence passing through the first light emitting slit to the silicon photocell detector, and the silicon photocell detector is used to detect whether the light source is stable. A detection tank, another part of the fluorescence passes through the beam splitter to the detection tank and irradiates the sample to be tested in the tank before being emitted; The second light entrance slit and the second grating, the emitted fluorescence passes through the second light entrance slit and is emitted to the second grating, and is then reflected by the second grating according to the set wavelength; The second light slit and the photomultiplier tube, the reflected fluorescence passes through the second light slit to the photomultiplier tube to obtain a detection signal; characterized in that: The light source also includes a light source box, the focusing concave mirror is arranged on a mirror body bracket located at one end of the light source box through an elastic support mechanism, and the mirror body bracket is also provided with an adjustment component for adjusting the deflection of the focusing mirror, the adjustment component includes a symmetrically arranged adjustment bolt and a compression spring, the tail of the adjustment bolt passes through the mirror body bracket and abuts against the back of the focusing concave mirror, and the compression spring abuts between the mirror body bracket and the back of the focusing concave mirror; The focusing concave mirror has a cavity protruding backward in the middle of the rear part of the mirror shell, and the elastic support mechanism is arranged in the cavity, including a support spring and a support bolt; an axial step hole is opened in the center of the cavity, and an annular groove is provided outside the step hole for limiting the support spring, one end of the support spring is against the lens, and the other end is arranged in the annular groove and against the rear wall of the cavity, a shaking ring with a conical inner hole is provided in the step hole, one end of the support bolt is a ball head arranged in the cavity and matched with the conical inner hole of the shaking ring, and the other end passes through the shaking ring, the rear wall of the cavity, and the mirror body bracket in sequence, and is fastened to the mirror body bracket by a nut.

2. The fluorescence detection system according to claim 1, characterized in that: A xenon lamp holder is provided in the light source box. The light source box has a top plate with a window for installing the xenon lamp. A pair of window baffles are provided on the top plate. A semicircular hole is provided on each of the two baffles, which are combined to form a clamping hole for fixing the upper end of the xenon lamp. The baffles are also provided with a waist-shaped hole for adjusting the fixed position on the top plate.

3. The fluorescence detection system according to claim 2, characterized in that: The focusing concave mirror includes a mirror housing, a lens and a retaining ring. The front end of the mirror housing is open, and the outer edge has several bolt holes. The lens is adapted to the mirror housing. The front end mirror surface of the lens is a concave aspherical surface. The lens is arranged in the mirror housing through the opening. The retaining ring is arranged in front of the lens and is fixed to the mirror housing by passing bolts through the corresponding bolt holes.

4. The fluorescence detection system according to claim 3, characterized in that: The lens is made of aluminum alloy, and a protective film is coated on the front mirror surface.

5. The fluorescence detection system according to claim 1, characterized in that: The first and second gratings each include a grating body, a rotating base for mounting the grating body, a driving device for driving the rotating base to rotate, a first sensing rod rotating synchronously with the rotating base, and a zero position sensor for detecting the first sensing rod. They also include a target position sensor arranged on one side of the zero position sensor and used to detect the first sensing rod, a second sensing rod rotating together with the driving device, and a calibration sensor for detecting the second sensing rod. The driving device includes a driving motor connected to the bottom of the rotating base and a reducer connected to the bottom of the driving motor, and the second sensing rod is connected to the main shaft of the reducer.

6. The fluorescence detection system according to claim 1, characterized in that: The detection tank includes a flow cell rack, a flow cell arranged in the flow cell rack, and a flow cell clamping head fixed at both ends of the flow cell for fixing the flow cell. The flow cell rack has a light inlet for fluorescence to enter and illuminate the flow cell with the substance to be tested, and a light outlet for fluorescence to emit. The flow cell is a liquid column flow cell or a capillary flow cell.

7. The fluorescence detection system according to claim 6, characterized in that: The detection system also includes a detection light-shielding chamber, and a mounting window is provided on the side of the detection light-shielding chamber; the detection tank also includes a connecting spacer provided at one end of the flow pool rack, and a fixing plate is also provided at one end of the connecting spacer. The connecting spacer and the flow pool rack are installed into the detection light-shielding chamber through the mounting window, and are fixed to the outer wall of the detection light-shielding chamber at the mounting window through the fixing plate.

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