Monitoring and compensating structure for eliminating EX spectrum fluctuation influence of fluorospectro photometer

Abstract

The utility model discloses a monitoring and compensating structure for eliminating the influence of EX spectrum fluctuation of a fluorospectro photometer, and particularly relates to the technical field of fluorescence analysis and detection, which comprises an EM light energy beam splitter, an EM wavelength energy matching tuner, a monitoring multiplier tube, an electronic negative feedback compensation control module and a measurement multiplier tube, the EM light energy beam splitter is arranged between a sample pool in the fluorescence spectrophotometer and the EM light energy beam splitter I, the EM light energy beam splitter splits EX light energy into two paths, the light beam I in the horizontal direction enters the fluorescence measurement channel to complete fluorescence testing, and the light beam II in the vertical direction enters the EX light energy monitoring channel to monitor the fluctuation of the EX light energy. According to the utility model, a monitoring light path structure of which the photoelectric characteristic of a monitoring light path is consistent with that of a measuring light path detector is designed to be embedded into a measuring light path and a circuit of an instrument, so that the correction compensation quantity of fluctuation quantity which is equal to sample fluorescence in quantity ratio and same in phase and synchronization is obtained in time to eliminate the error influence caused by EX energy fluctuation in a fluorescence test.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of fluorescence analysis and detection technology, more specifically to a monitoring and compensation structure for eliminating the influence of EX spectrum fluctuation of a fluorescence spectrophotometer. BACKGROUND

[0002] When a substance with fluorescence characteristics is irradiated by light, it will be excited to emit light. The self-emission of the sample is called fluorescence. The relationship between the fluorescence intensity and the EX light energy of the instrument can be expressed by the following formula: In the formula, F represents the relative fluorescence intensity, K represents a constant related to the gain (detection efficiency) of the instrument, I represents the intensity of the EX excitation light, Φ represents the fluorescence emission efficiency of the measured substance, and C represents the concentration of the sample.

[0003] When the relevant parameters of the instrument are selected and the physical properties of the measured substance are determined, the measured fluorescence intensity F is proportional to the excitation light intensity I. Therefore, the instrument can be used for qualitative testing. If a emission spectrum scan is performed, the fluorescence spectral characteristics of the measured substance can be obtained. In quantitative analysis, different concentrations C have different fluorescence intensity F values, and the concentration C is proportional to the fluorescence intensity F.

[0004] The working principle of the fluorescence instrument is as follows: the fluorescence spectrophotometer is an instrument for analyzing the fluorescence spectrum and fluorescence intensity of a measured substance. Its basic principle is to use a light source, pass the EX spectrometer to obtain an excitation spectrum of a specific wavelength, and then pass the EX light energy beam splitter to divide the excitation spectrum into two beams according to a certain proportion. One beam enters the sample cell, and the other beam enters the EX wavelength energy matching tuner. The excitation spectrum that enters the sample cell irradiates the sample. After the sample absorbs the light energy, it enters the excited state and emits outcoming light with a longer wavelength than the incident light (many fluorescent substances stop emitting light as soon as the incident light stops, and the outcoming light with this property is called fluorescence). The outcoming light from the sample cell is emitted by the EM spectrometer to obtain an EM emission spectrum of a specific wavelength. The EM emission spectrum of a specific wavelength enters the measurement multiplier tube to obtain a measurement current signal. The measurement current signal enters the signal processing J, which optimizes and reduces the noise of the measurement current signal, and then performs high-precision and high-speed AD analog-to-digital conversion to obtain an original digital signal. The display K receives the original digital signal, optimizes it by software algorithm, and displays the stable and reliable fluorescence intensity signal in the form of a graph or a number. The fluorescence spectrophotometer can provide many physical parameters, including the excitation spectrum, the emission spectrum, the fluorescence intensity, the quantum yield, the fluorescence lifetime, and the fluorescence polarization. These parameters can be used for qualitative and quantitative fluorescence analysis of substances.

[0005] Currently, the fluorescence instrument has the following related problems: 1. The fluorescence intensity precision error of sample testing is related to the size of the EX spectrum fluctuation. 2. The EX spectrum energy fluctuation of the instrument is closely related to the thermal stability of the light source.

[0006] Further, from the information of the manufacturing and acceptance standards of the fluorescence spectrophotometer, it can be known that:

[0007] 1. Most of the present fluorescence spectrophotometers adopt a single-beam optical path structure, so it is known from the manufacturing principle of the single-beam spectrometer that the instrument does not have the function of automatically eliminating the influence of EX light fluctuation.

[0008] 2. A few high-end instruments have taken measures to monitor the fluctuation of the light source, but since the detector with semiconductor photoelectric characteristics is used in the monitoring light path, it will produce the problem of different amounts of asynchronization of the photoelectric conversion of the photomultiplier in the measurement light path, specifically, the complexity of the correction compensation technology and algorithm of the different amounts of asynchronization of the feedback difference of the conversion of the monitoring light energy fluctuation into electric quantity, so that the correction effect is poor and not practical. Practical new type content

[0009] In order to overcome the above-mentioned defects of the prior art, the utility model provides a monitoring and compensation structure for eliminating the influence of EX light spectrum fluctuation of a fluorescence spectrophotometer, which is characterized in that a monitoring light path structure with photoelectric characteristics consistent with the detector in the measurement light path is embedded in the measurement light path and the circuit of the instrument, so that the correction compensation amount of the fluctuation amount synchronous with the sample fluorescence in the same phase ratio is obtained in real time to eliminate the error influence caused by the EX energy fluctuation in the fluorescence test, that is, the single-beam fluorescence instrument has the correction compensation function of the quasi-double-beam spectrometer in the technical concept.

[0010] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme: a monitoring and compensation structure for eliminating the influence of EX light spectrum fluctuation of a fluorescence spectrophotometer, comprising an EM light energy beam splitter, an EM wavelength energy matching tuner, a monitoring photomultiplier, an electronic negative feedback compensation control module and a measurement photomultiplier, the EM light energy beam splitter is arranged between a sample cell and an EM light splitter in the fluorescence spectrophotometer, and the EX light energy beam splitter can eliminate the measurement error caused by the EX light spectrum energy fluctuation in the fluorescence test in real time. The EM light energy beam splitter divides the EX light energy into two paths, light beam one in the horizontal direction enters a fluorescence measurement channel to complete the fluorescence test, and light beam two in the vertical direction enters an EX light energy monitoring channel to monitor the EX light energy fluctuation, and the light beam two passes through the EM wavelength energy matching tuner, the monitoring photomultiplier, the electronic negative feedback compensation control module and the measurement photomultiplier to realize the synchronous correction of the EX fluctuation influence.

[0011] Preferably, the input end of the EM spectrometer one is provided with a light source, the EM light energy beam splitter is connected to the output end of the EM spectrometer one, the sample cell is connected to the output end of the EM light energy beam splitter, the output end of the sample cell is provided with an EM spectrometer two, and the output end of the EM spectrometer two is connected to the input end of the measuring multiplier tube; the spatial light energy beam splitter of the EX light path in front of the sample cell is used for light beam one, so as to ensure that the fluctuation of sample fluorescence and the correction of the fluctuation are synchronized in time and phase, that is, the principle of the compensation method is correct and reliable.

[0012] Preferably, the EM wavelength energy matching tuner is arranged at the output end of the EM light energy beam splitter, the monitoring multiplier tube is connected to the output end of the EM wavelength energy matching tuner, the electronic negative feedback compensation control module is arranged at the output end of the monitoring multiplier tube, and the output end of the electronic negative feedback compensation control module is connected to the input end of the measuring multiplier tube; the energy of light beam two is tuned by the EM wavelength energy matching tuner, so as to achieve the best matching compensation effect of feedback compensation, then the EX fluctuation compensation energy matched by light beam two is obtained after the monitoring multiplier tube, and then the fluctuation negative feedback compensation calibration is obtained, and then the test sensitivity value set in advance is obtained through the electronic negative feedback compensation control module for compensation calibration, so as to obtain the sensitivity correction and then reach the measuring multiplier tube to obtain the synchronous correction of the EX fluctuation influence.

[0013] Preferably, the wavelength response range of the double photomultiplier tubes composed of the monitoring multiplier tube and the measuring multiplier tube is 200-900 nm, and the same photoelectric characteristic double multiplier tube light path structure is adopted in the measuring and monitoring light paths, so as to prevent the phase synchronization problem of negative feedback signal compensation caused by different photoelectric conversion characteristics, that is, the self-oscillation problem of the signal in the feedback control technology is solved.

[0014] Preferably, the energy negative high voltage correction range of the EM wavelength energy matching tuner is 50-800 V.

[0015] Preferably, the output end of the measuring multiplier tube is connected with a signal processing module, and the output end of the signal processing module is provided with a display module; the measurement current signal output by the measuring multiplier tube enters the signal processing module, the signal processing module optimizes and reduces the noise of the measurement current signal, and then performs analog-to-digital conversion to obtain an original digital signal, and the display module displays the fluorescence intensity signal in the form of a graph or a number after receiving the original digital signal.

[0016] Preferably, the electronic negative feedback compensation control module comprises a high voltage module arranged at the input end of the monitoring multiplier tube and the measuring multiplier tube, a triode is connected to the input end of the high voltage module, an operational amplifier two is arranged at the input end of the triode, an operational amplifier one is connected to the input end of the operational amplifier two, the output end of the monitoring multiplier tube is connected to the negative electrode of the operational amplifier one, resistors R1, R2 and R3 are respectively connected to the operational amplifier one, the operational amplifier two and the triode, a plurality of feedback resistors are connected in parallel to the operational amplifier one, and an analog circuit switch is connected in series to the circuit of each feedback resistor, and the sensitivity of the fluorescent system measuring signal is adjusted by selecting different feedback resistances through the analog circuit switch.

[0017] The technical effects and advantages of the present application are as follows:

[0018] 1. The EX light energy beam splitter is used to realize that once the EX spectrum energy fluctuation is monitored in the fluorescent test, the measurement error caused by the fluctuation can be eliminated synchronously, the EX wavelength energy matching tuner is used to solve the technical problem of under-compensation or over-compensation of feedback in the negative feedback automatic control technology to ensure the compensation effect, that is, to solve the feedback quantity control problem. Compared with the prior art, the EX light energy beam splitter and the energy EX wavelength energy matching tuner are arranged scientifically and reasonably on the fluorescent spectrophotometer, so that the single-beam fluorescent instrument can simply eliminate the influence of the fluorescent detection error caused by the light source fluctuation of the fluorescent spectrometer, and the complexity of the manufacturing technology is not increased like the double-beam spectrometer.

[0019] 2. The monitoring and measuring light path double photomultiplier tube technology is used to avoid the monitoring compensation failure problem caused by the circuit feedback self-oscillation and other circuit technical factors caused by the different photoelectric characteristics and different quantity ratios of the detector in other ways.

[0020] 3. The present application ensures that the test error caused by the EX light energy fluctuation can be eliminated synchronously in real time during the sample fluorescent detection, that is, it is more conducive to the test stability of the sample fluorescence of the instrument. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the overall structure diagram of the present application;

[0022] Figure 2 It is the electronic negative feedback compensation control module block circuit diagram of the present application;

[0023] The figure marks are as follows: 1, light source; 2, EM spectrometer one; 3, EM light energy beam splitter; 4, sample cell; 5, EM wavelength energy matching tuner; 6, monitoring multiplier tube; 7, electronic negative feedback compensation control module; 8, EM spectrometer two; 9, measuring multiplier tube; 10, signal processing module; 11, display module.

[0024] 71 high voltage module; 72, triode; 73, operational amplifier two; 74, operational amplifier one; 75, analog circuit switch; 76, feedback resistor. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be apparently and completely described in conjunction with the drawings of the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the utility model.

[0026] Referring to the drawings in the specification Figure 1 The utility model provides the monitoring and compensation structure of eliminating the influence of EX spectral fluctuation of fluorescence spectrophotometer, including EM light energy beam splitter 3 between sample cell 4 and EM spectrometer one 2 in fluorescence spectrophotometer, the EM wavelength energy matching tuner 5 of disposing light energy beam splitting, the monitoring multiplier tube 6 of receiving the matching compensation amount of disposition, obtains the electronic negative feedback compensation control module 7 of matching compensation amount, the measurement multiplier tube 9 of disposition can obtain compensation feedback correction.

[0027] The input end of the EM spectrometer one 2 is provided with a light source 1, the EM light energy beam splitter 3 is connected to the output end of the EM spectrometer one 2, the EM light energy beam splitter 3 divides the EX light energy into two paths, the light beam one in the horizontal direction enters the fluorescence measurement channel to complete the fluorescence test, and the light beam two in the vertical direction enters the EX light energy monitoring channel to monitor the EX light energy fluctuation.

[0028] In the passage of the light beam one:

[0029] The sample cell 4 is connected to the output end of the EM light energy beam splitter 3, the output end of the sample cell 4 is provided with an EM spectrometer two 8, the output end of the EM spectrometer two 8 is connected to the input end of the measurement multiplier tube 9, the light beam one adopts the spatial light energy beam splitting in front of the EX light path of the sample cell 4, ensures that the fluctuation of the fluorescence generated by the sample and the correction of the fluctuation are synchronous in time and phase, that is, ensures that the compensation method principle is correct and reliable.

[0030] Moreover, the output end of the measurement multiplier tube 9 is connected with a signal processing module 10, the output end of the signal processing module 10 is provided with a display module 11, the measurement current signal output by the measurement multiplier tube 9 enters the signal processing module 10, the signal processing module 10 carries out optimized noise reduction processing to the measurement current signal and then carries out analog-digital conversion to obtain an original digital signal, and the display module 11 displays the fluorescence intensity signal in the form of figure or number after receiving the original digital signal.

[0031] In the passage of the light beam two:

[0032] The EM wavelength energy matching tuner 5 is located at the output end of the EM light beam splitter 3. The monitoring multiplier tube 6 is connected to the output end of the EM wavelength energy matching tuner 5. The electronic negative feedback compensation control module 7 is located at the output end of the monitoring multiplier tube 6. The output end of the electronic negative feedback compensation control module 7 is connected to the input end of the measurement multiplier tube 9. The wavelength response range of the dual photomultiplier tube composed of the monitoring multiplier tube 6 and the measurement multiplier tube 9 is 200-900nm.

[0033] The EX beam splitter 3 is placed after the exit slit of the EM beam splitter 2 and before irradiating the sample under test. The second beam is used as a monitoring beam and enters the EM wavelength energy matching tuner 5. The monitoring light energy entering the EM wavelength energy matching tuner 5 is tuned to the matching compensation energy amplitude by the pre-programmed brightness reference parameters and then enters the monitoring multiplier tube 6. After photoelectric conversion by the monitoring quantity multiplier tube 9, the real-time fluctuation correction amount can be obtained and enters the electronic negative feedback compensation control module 7 for sensitivity feedback compensation correction of the test detector.

[0034] Specifically, such as Figure 2 As shown, the electronic negative feedback compensation control module 7 includes a high voltage module 71 (HVPM) located at the input terminals of the monitoring multiplier tube 6 (PMT2) and the measuring multiplier tube 9 (PMT1). The output terminal of the high voltage module 71 simultaneously provides a negative high voltage to both the monitoring multiplier tube 6 and the measuring multiplier tube 9. A transistor 72 (NPN) is connected to the input terminal of the high voltage module 71. A resistor R3 is connected to the transistor 72. The transistor 72 adjusts the voltage across the resistor R3 for use by the high voltage module 71. The higher the voltage across the resistor R3, the greater the negative high voltage output by the high voltage module 71.

[0035] The input terminal of the transistor 72 is equipped with an operational amplifier 2 73 (OP-AMP2), and a resistor R2 is connected to the operational amplifier 2 73. The input terminal of the operational amplifier 2 73 is connected to an operational amplifier 1 74 (OP-AMP1), and a resistor R1 is connected to the operational amplifier 1 74. The output terminal of the monitoring multiplier tube 6 is connected to the negative terminal of the operational amplifier 1 74. Multiple feedback resistors 76 (RF1, RF2...RFn) are connected in parallel to the operational amplifier 1 74, and an analog circuit switch 75 (S1, S2...Sn) is connected in series on the line of each feedback resistor 76. The sensitivity of the fluorescence system measurement signal is adjusted by selecting different feedback resistors 76 through the analog circuit switch 75.

[0036] The circuit monitoring compensation principle is that the EX light energy beam splitter 3 divides the EX light energy into two beams: one horizontal light beam enters the fluorescence measurement channel to complete fluorescence test; the other vertical light beam enters the EX light energy monitoring channel to monitor EX light energy fluctuation. When the light energy of the light source 1 instantaneously increases, the light energy entering the PMT 2 becomes stronger, and the PMT 2 converts more negative electrons into the OP-AMP 1. At this time, the OP-AMP 1 reversely outputs higher voltage into the OP-AMP 2, and the OP-AMP 2 reversely outputs lower voltage. At this time, the NPN outputs lower voltage to R3, and the HVPM outputs lower negative high voltage. At this time, the PMT 2 signal is suppressed and reduced, which offsets the increase of the fluctuation signal of the PMT 2. The whole circuit monitoring system and the measurement system are not affected by the fluctuation of the light source 1. The whole loop feedback system offsets the influence of the instantaneous fluctuation of the light energy of the light source 1. Similarly, when the light energy of the light source 1 instantaneously decreases, the whole loop feedback system offsets the influence of the decrease of the light energy, so as to realize monitoring and feedback control on the circuit to offset the fluctuation of the light source 1 or the EX light source.

[0037] Working principle of the utility model:

[0038] When the light source 1 of the instrument has positive and negative fluctuation in brightness, the EX light output of the light splitter has synchronous fluctuation in the same proportion. Since the EX light energy beam splitter 3 is placed in front of the sample cell 4, the sample fluorescence and the monitor also have the same proportion and synchronous fluctuation of light energy. The self-control program and the matching hardware negative feedback compensation link designed in the utility model instantaneously eliminate the fluctuation influence on the measurement detector.

[0039] Finally, the above-mentioned is only preferred embodiment of the utility model, and is not used for limiting the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. Monitoring and compensation structure for eliminating the influence of EX spectral fluctuations of a fluorescence spectrophotometer, characterized in that it comprises: It comprises EM light energy beam splitter (3), EM wavelength energy matching tuner (5), monitoring multiplier tube (6), electronic negative feedback compensation control module (7) and measuring multiplier tube (9), the EM light energy beam splitter (3) is arranged between sample cell (4) and EM spectrometer (2) in the fluorescence spectrophotometer, and the EM light energy beam splitter (3) splits EX light energy into two ways; The light beam one in horizontal direction enters the fluorescence measuring channel to complete fluorescence test; The light beam two in vertical direction enters EX light energy monitoring channel to monitor EX light energy fluctuation; The light beam two passes through EM wavelength energy matching tuner (5), monitoring multiplier tube (6), electronic negative feedback compensation control module (7) and measuring multiplier tube (9) to realize synchronous correction of EX fluctuation influence.

2. The monitoring and compensation structure for eliminating the influence of EX spectral fluctuation of a fluorescence spectrophotometer according to claim 1, characterized in that: The input end of the EM spectrometer (2) is provided with light source (1), the EM light energy beam splitter (3) is connected to the output end of the EM spectrometer (2), the sample cell (4) is connected to the output end of the EM light energy beam splitter (3), and the output end of the sample cell (4) is provided with EM spectrometer (8), and the output end of the EM spectrometer (8) is connected to the input end of the measuring multiplier tube (9); The light beam one adopts spatial light energy splitting in front of the EX light path of the sample cell (4), to ensure that the fluctuation of the fluorescence generated by the sample and the correction of the fluctuation are synchronous in time and phase, that is, to ensure that the compensation method principle is correct and reliable.

3. The monitoring and compensating structure for eliminating the influence of EX spectral fluctuation of a fluorescence spectrophotometer according to claim 1, characterized in that: The EM wavelength energy matching tuner (5) is arranged at the output end of the EM light energy beam splitter (3), the monitoring multiplier tube (6) is connected to the output end of the EM wavelength energy matching tuner (5), the electronic negative feedback compensation control module (7) is arranged at the output end of the monitoring multiplier tube (6), and the output end of the electronic negative feedback compensation control module (7) is connected to the input end of the measuring multiplier tube (9); The light beam two is energy tuned through the EM wavelength energy matching tuner (5), so that the feedback compensation has the best matching compensation effect, then the EX fluctuation compensation energy matched by the light beam two is obtained after the monitoring multiplier tube (6), and then the fluctuation negative feedback compensation calibration is obtained, and then the test sensitivity value set in advance is compensated and calibrated through the electronic negative feedback compensation control module (7), so that the sensitivity is corrected and then reaches the measuring multiplier tube (9) to realize synchronous correction of EX fluctuation influence.

4. The monitoring and compensating structure for eliminating the influence of EX spectral fluctuation of a fluorescence spectrophotometer according to claim 1, characterized in that: The monitoring multiplier tube (6) and the measuring multiplier tube (9) form a double photomultiplier wavelength response range of 200-900nm.

5. The monitoring and compensation structure for eliminating the influence of EX spectral fluctuation of a fluorescence spectrophotometer according to claim 1, characterized in that: The EM wavelength energy matching tuner (5) has an energy negative high voltage correction range of 50-800V.

6. The monitoring and compensation structure for eliminating the influence of EX spectral fluctuation of a fluorescence spectrophotometer according to claim 1, characterized in that: The output end of the measuring multiplier tube (9) is connected with a signal processing module (10), and the output end of the signal processing module (10) is provided with a display module (11). The measuring current signal output by the measuring multiplier tube (9) enters the signal processing module (10), the signal processing module (10) optimizes and denoises the measuring current signal, and then performs analog-digital conversion to obtain an original digital signal, and the display module (11) displays the fluorescence intensity signal in the form of figure or number after receiving the original digital signal.

7. The monitoring and compensation structure for eliminating the influence of EX spectral fluctuation of a fluorescence spectrophotometer according to claim 1, characterized in that: The electronic negative feedback compensation control module (7) comprises a high voltage module (71) arranged at the input end of the monitoring multiplier tube (6) and the measuring multiplier tube (9), the input end of the high voltage module (71) is connected with a triode (72), the input end of the triode (72) is provided with an operational amplifier two (73), the input end of the operational amplifier two (73) is connected with an operational amplifier one (74), the output end of the monitoring multiplier tube (6) is connected with the negative electrode of the operational amplifier one (74), the operational amplifier one (74), the operational amplifier two (73) and the triode (72) are respectively connected with resistors R1, R2 and R3; A plurality of feedback resistors (76) are connected in parallel on the operational amplifier one (74), and an analog circuit switch (75) is connected in series on the line of each feedback resistor (76), and the sensitivity of the fluorescent system measuring signal is adjusted by selecting different feedback resistors (76) through the analog circuit switch (75).

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