Online continuous detection system and method for feed components

Abstract

The invention discloses an online continuous detection system and method for feed components, and belongs to the technical field of production detection. Feed particles are made into powder, the humidity is measured, the ionization temperature is determined according to the humidity, the electric field intensity is adjusted, ionized ions are conveyed to the repulsion device through the transmission device, and the ions are conveyed to the analysis device by applying pulse voltage to the repulsion electrode. According to the data received by the analysis device, the type and content of the to-be-detected components in the feed are obtained, meanwhile, the activation time of the analysis device is calibrated according to the collection time of matrix ions in the feed, and the sampling drift of the system is reduced. Detection parameters are adjusted according to the physical form and chemical components of feed particles, non-stop continuous detection is achieved, and the device is suitable for large-scale production and meets the requirements of the workshop working environment.

Description

Technical Field

[0001] The present invention relates to the technical field of production detection, and in particular to an online continuous detection system and method for feed ingredients. Background Art

[0002] Mass spectrometry detection technology can be used to detect pesticide residues, heavy metals, antibiotics, and toxins in feed. Specifically, a liquid sample is first prepared, and sample ions are ionized from the liquid sample. The composition and content of the sample ions are predicted based on the mass-to-charge ratio and signal intensity of the sample ions. These methods require offline preparation of liquid samples, which makes it difficult to achieve online continuous detection and cannot be applied to large-scale production. Chinese patent application publication number CN109813798A discloses a method for online continuous monitoring of hazardous chemicals or rapid identification of leaked substances. The method uses a reagent-assisted vacuum ultraviolet lamp as an ionization source and continuously works through an ion mobility spectrometer to achieve online continuous monitoring of hazardous chemicals. At the same time, standard gas is used to perform real-time correction of the signal intensity of the detected gas sample to continuously monitor the changes in the concentration of hazardous chemicals. Since feed is a solid sample, product uniformity is difficult to ensure, and online continuous detection is difficult. In addition, the feed production environment is relatively harsh, and its detection clock, sampling time, etc. will gradually drift with the increase of working time. In order to avoid data drift, the existing detection method must be shut down for debugging once after each detection cycle. Therefore, the existing technology needs to be further improved. Summary of the invention

[0003] In order to solve the defects of the online continuous detection technology in the above-mentioned feed production process, the present invention proposes an online continuous detection system and method for feed ingredients, which adjusts the ionization parameters of the ionization device according to the physical properties of the feed to adapt to feed particles with different outputs, and calibrates the activation time of the analysis device to reduce the downtime for calibration.

[0004] The technical solution of the present invention is achieved in this way: An online continuous detection system for feed ingredients, comprising: a detection branch, a grinding device, a pre-detection device, a sample delivery device, an air supply device, an ionization device, a transmission device, a repulsion device, a migration device, an analysis device, a data processing device, a first calibration device, and a second calibration device, wherein: The detection branch is configured to receive feed particles from a conveyor belt; The grinding device is configured to form feed powder from feed particles; The pre-check device is configured to measure the current moisture content of the feed powder; The sample delivery device is configured to provide feed powder to the first channel; The gas supply device is configured to provide a gas solvent to the first channel; The ionization device is configured to ionize sample ions from the feed powder and drive the ions into the second channel; The transmission device is configured to modulate the sample ions into an ion beam and drive the ion beam into the third channel; The repeller is configured to adjust the flight speed of the ion beam; The migration device is configured to direct the ion beam into the analysis device; The analysis device is configured to receive matrix ions and analyte ions in the ion beam; The data processing device is configured to detect the measured content of the matrix and the measured content and mass-to-charge ratio of the component to be measured; The first calibration device is configured to calibrate an ionization parameter of the ionization device according to the current humidity of the feed powder; The second calibration device is configured to calibrate the activation time of the analysis device according to the measured content of the matrix.

[0005] The present invention further comprises a first suction device and a second suction device, wherein the first suction device is configured to extract the remaining feed powder and the gas solvent from the ionization device, and the second suction device is configured to extract the gas solvent from the transmission device and the migration device.

[0006] An online continuous detection method according to the online continuous detection system for feed ingredients comprises the following steps: Step 1: A conveyor belt continuously transports feed particles, the conveyor belt is connected to a detection branch, a grinding device and a pre-detection device are sequentially arranged in the detection branch, and the feed particles have a matrix and at least one component to be detected; Step 2: The grinding device makes feed particles into feed powder, the pre-detection device measures the current humidity of the feed powder, and calibrates at least one ionization parameter of the ionization device according to the current humidity; Step 3: The sample delivery device inhales feed powder from the detection branch and provides the feed powder to the first channel, and the gas supply device provides gas solvent to the first channel; Step 4: the ionization device in the first channel ionizes sample ions from the feed powder based on the ionization parameters, the sample ions enter the second channel, and the remaining feed powder and gas solvent return to the detection branch; Step 5: The transmission device in the second channel modulates the sample ions into an ion beam and drives the ion beam into the third channel; Step 6: applying a pulse voltage to the repelling device, and the matrix ions and the component ions to be measured in the ion beam pass through the repelling device and the migration device respectively and enter the analysis device; Step 7: starting the analysis device at the start time t0, the analysis device receives the matrix ions at the first collection time t1 and receives the component ions to be measured at the second collection time t2; Step 8: Calculate the calibration acquisition time t3 according to the mass-to-charge ratio of the matrix ions, and then calibrate the activation time t4 according to the first acquisition time t1 and the calibration acquisition time t3; Step 9: Calculate the mass-to-charge ratio of the component ion to be measured according to the second acquisition time t2, generate the measured content of the component to be measured according to the signal intensity at the second acquisition time t2, output the mass-to-charge ratio and the measured content of the component to be measured, and return to step 2.

[0007] In the present invention, the matrix is ​​one or more of vitamins, proteins or carbohydrates, the components to be detected are one or more of heavy metals, toxins or pesticides, and the gas solvent is nitrogen.

[0008] In the present invention, in step 2, the ionization parameters include ionization temperature and electric field strength, the humidity difference between the current humidity and the calibrated humidity is calculated, the compensation temperature is calculated according to the humidity difference, the ionization temperature is calculated according to the compensation temperature, and if the ionization temperature is greater than the system linear temperature, the electric field strength of the ionization device is adjusted according to the ionization temperature and the pressure of the first channel.

[0009] In the present invention, in step 6, the matrix ions and the component ions to be detected in the ion beam pass through the migration device along the first flight speed v1 and the second flight speed v2 respectively.

[0010] In the present invention, in step 7, the signal intensity of the matrix is ​​determined according to the reference content of the matrix, and the moment with the signal intensity is found as the first acquisition moment t1.

[0011] In the present invention, in step 8, the sampling drift Δt is calculated according to the first acquisition time t1 and the calibration acquisition time t3, and the activation time t4 = t0 + Δt.

[0012] In the present invention, in step 9, the flight time of the component ion to be measured is determined according to the activation time t4 and the second acquisition time t2, and the mass-to-charge ratio and molar mass of the component ion to be measured are calculated according to the flight time of the component ion to be measured.

[0013] In the present invention, in step 9, a response function is generated according to the response ratios at multiple different calibrated contents, and then the response ratio of the component to be measured at the second acquisition time t2 is calculated, and the actual measured content of the component to be measured is determined according to the response ratio and the response function.

[0014] The online continuous detection system and method of feed ingredients implemented in the present invention have the following beneficial effects: the present invention first measures the humidity of the feed powder, and adjusts the ionization temperature of the ionization device according to the humidity, so that feeds with different production humidity can be effectively ionized. In order to avoid system response delay caused by too high ionization temperature, the present invention adjusts the electric field strength at high temperature. The present invention calibrates the activation time of the analysis device according to the difference between the calibration collection time of the matrix and the first collection time, reduces the sampling drift of the system, and avoids the accumulation of errors in continuous detection. The present invention adjusts the detection parameters in combination with the physical form and chemical composition of the feed particles to achieve continuous detection without stopping, which is suitable for large-scale production and meets the requirements of the workshop working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a block diagram of an online continuous detection system for feed ingredients of the present invention; Figure 2 It is a structural schematic diagram of the online continuous detection system of feed ingredients of the present invention; Figure 3 It is a schematic diagram of the detection part of the online continuous detection system of feed ingredients of the present invention; Figure 4 It is a flow chart of the online continuous detection method of the present invention; Figure 5 is a schematic diagram of an ionization device of the present invention; Figure 6 is a schematic diagram of a transmission device of the present invention; Figure 7 is a schematic diagram of a repulsion device of the present invention; Figure 8 is a schematic diagram of the migration device of the present invention; Fig. 9 is a mass spectrum of a preferred feed particle; Fig.10 A schematic diagram of a clock cycle in which sampling drift occurs in the present invention; Fig.11 It is a schematic diagram of the relationship between various moments of the present invention; Fig.12 It is a response function diagram of the content and response ratio of the present invention; Fig.13 It is a schematic diagram of various parameters in the repulsion device and the migration device of the present invention.

[0016] Reference numerals in the accompanying drawings: 101 sample delivery port, 102 gas supply port, 103 vacuum ultraviolet krypton lamp, 104 transmission electrode, 105 driving electrode, 106 first hole electrode, 107 sample delivery device, 108 first channel, 109 ionization device, 110 first suction device, 201 radio frequency transmission area, 202 second hole electrode, 203 quadrupole rod, 204 electrostatic transmission area, 205 flat plate electrode, 206 slit, 207 transmission device, 208 The second channel, 209 the second suction device, 301 the repulsion electrode, 302 the repulsion zone, 303 the acceleration zone, 304 the field-free channel, 305 the first reflection zone, 306 the second reflection zone, 307 the reflection electrode, 308 the third channel, 309 the repulsion device, 310 the migration device, 311 the analysis device, 312 the data processing device, 401 the conveyor belt, 402 the detection branch, 403 the grinding device, 404 the pre-inspection device, 405 the gas replenishing device. DETAILED DESCRIPTION

[0017] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0018] The existing continuous feed detection technology has high requirements on sample uniformity and requires periodic shutdown for calibration, which is difficult to be applied to industrial continuous production. The online continuous feed component detection system and method of the present invention adjusts the detection parameters in combination with the physical form and chemical composition of feed particles to achieve continuous detection without stopping, which is suitable for large-scale production and meets the requirements of workshop working environment. Embodiment 1

[0019] like Figures 1 to 3The online continuous detection system of feed ingredients of the present invention includes: a detection branch 402, a grinding device 403, a pre-detection device 404, a sample delivery device 107, a gas supply device 405, an ionization device 109, a transmission device 207, a repulsion device 309, a migration device 310, an analysis device 311, a data processing device 312, a first calibration device, and a second calibration device. The detection branch 402 is configured to receive feed particles from a conveyor belt 401. The grinding device 403 is configured to make feed particles into feed powder. The pre-detection device 404 is configured to measure the current humidity of the feed powder. The sample delivery device 107 is configured to provide feed powder to the first channel 108. The gas supply device 405 is configured to provide a gas solvent to the first channel 108. The ionization device 109 is configured to ionize sample ions from the feed powder and drive the sample ions into the second channel 208. The transmission device 207 is configured to modulate the sample ions into an ion beam and drive the ion beam into the third channel 308. The repelling device 309 is configured to adjust the flight speed of the ion beam. The migration device 310 is configured to guide the matrix ions and the ions of the component to be measured to pass through the field-free channel 304, and the ion beam enters the analysis device. The analysis device 311 is configured to receive the matrix ions and the ions of the component to be measured in the ion beam. The data processing device 312 can be a computer, which is configured to detect the measured content of the matrix and the measured content and mass-to-charge ratio of the component to be measured. The first calibration device is configured to calibrate the ionization parameters of the ionization device according to the current humidity of the feed powder. The second calibration device is configured to calibrate the activation time of the analysis device according to the measured content of the matrix. Finally, the mass spectrogram and other data are displayed by the data display device. The system also includes a first suction device 110 and a second suction device 209, the first suction device 110 is configured to extract the remaining feed powder and gas solvent from the ionization device 109, and the second suction device 209 is configured to extract the gas solvent from the transmission device 207 and the migration device 310.

[0020] Reference Figure 2 The system first transports a small amount of feed particles on the conveyor belt to the grinding device 403 through the detection branch 402. The grinding device 403 makes the feed particles into powder. At the same time, the pre-detection device 404 measures the current humidity of the feed powder and compares it with the calibration humidity. The ionization parameters in the ionization device 109 are calibrated by the first calibration device. Figure 3The sample delivery device sucks feed powder from the grinding device 403, and the feed powder enters the first channel 108 from the sample delivery port, and the gas supply device 405 provides gas solvent to the first channel 108 from the gas supply port. The ionization device 109 in the first channel 108 transports the ionized sample ions to the second channel 208. Then the transmission device 207 in the second channel 208 focuses and modulates the ion beam into the third channel 308. Then the ions are transported to the migration device 310 under the action of the repulsion device 309 in the third channel 308. The ions moving in the migration device 310 enter the analysis device 311 through reflection. The analysis device 311 receives these ions and transmits the data to the data processing device 312. The data processing device 312 draws a mass spectrum according to the obtained data analysis and calculates the content of the component to be measured. In the whole detection process, in order to ensure the sensitivity of the instrument, the whole system needs to be in a high vacuum environment to ensure that the ions have enough free path, and to ensure that the sample ions do not collide with neutral gas molecules during the flight process, thereby affecting the flight time of the ions. The present invention uses the first suction device 110 and the second suction device 209 to maintain a high vacuum environment in the system. At the same time, the present invention calibrates the activation time of the analysis device 311 through the second calibration device.

[0021] The present invention adjusts the ionization temperature of the ionization device 109 according to the current humidity, so that feeds with different production humidity can be effectively ionized. In order to avoid the system response delay caused by too high ionization temperature, the present invention adjusts the electric field strength at high temperature. The present invention searches for the corresponding first acquisition time t1 according to the signal strength of the matrix, and calibrates the activation time of the analysis device 311 according to the first acquisition time t1 of the matrix and the flight time, thereby reducing the influence of the sampling drift of the system on the detection result. Embodiment 2

[0022] like Figures 4 to 12 The online continuous detection method of the online continuous detection system of feed ingredients of the present invention includes the following steps.

[0023] Step 1: The conveyor belt continuously transports feed particles, and the conveyor belt is connected to a detection branch, in which a grinding device and a pre-detection device are sequentially arranged, and the feed particles have a matrix and at least one component to be detected. The matrix is ​​one or more of vitamins, proteins or carbohydrates, the component to be detected is one or more of heavy metals, toxins or pesticides, and the gas solvent is nitrogen.

[0024] Step 2: The grinding device makes the feed particles into feed powder, and the pre-detection device measures the current humidity of the feed powder, and calibrates at least one ionization parameter of the ionization device according to the current humidity. It is difficult to keep the humidity of the feed powder consistent during the production process, and the humidity of the powder will affect the effect of subsequent ionization, so it is necessary to adjust the relevant ionization parameters according to the humidity to offset this effect. In this embodiment, the humidity difference between the current humidity and the calibrated humidity is calculated, and the compensation temperature is calculated according to the humidity difference. The ionization temperature is calculated by the compensation temperature. If the ionization temperature is greater than the system linear temperature, the electric field strength of the ionization device 109 is adjusted according to the ionization temperature and the pressure of the first channel 108. The calibrated humidity is, for example, 12%, and the system linear temperature is, for example, 50°C. When the humidity of the powder is too high, the ionization temperature is appropriately increased to facilitate the evaporation of water and reduce the interference of water vapor on subsequent component detection. However, when the ionization temperature is too high, the initial kinetic energy of the ionized ions is high. In addition, the pressure of the first channel 108 will affect the collision frequency between ions, thereby affecting the diffusion rate of ions, so it is necessary to readjust the electric field strength of the ionization device 109 to reduce the negative effects of these two effects.

[0025] Specifically, the current humidity H1 of the feed powder is measured by the pre-detection device 404, and then the humidity difference H´=H1-H0 is calculated according to the calibrated humidity H0. The compensation coefficient k is set, and its value is, for example, k=0.1°C. The compensation temperature T´=kH´ is calculated according to the humidity difference H´ and the compensation coefficient k, and then the ionization temperature is adjusted to T1=T0+T´ according to the compensation temperature T´ and the calibrated ionization temperature T0. The system linear temperature T2 for stable operation of the system, if the ionization temperature T1 is greater than the system linear temperature T2, then the electric field strength is adjusted according to the difference between the ionization temperature T1 and the system linear temperature T2 and the pressure P1 of the first channel 108. The adjusted electric field strength is E´=E0+α(T1-T2)+βP1, where E0 is the calibrated electric field strength, which is approximately 6×10 6 V / m. α and β are temperature adjustment coefficient and pressure adjustment coefficient respectively, and their values ​​are, for example, α=-0.8×10 6 V / (m·℃), β=-0.2×10 5 V / (m·Pa).

[0026] Step 3: The sample delivery device inhales feed powder from the detection branch and provides feed powder to the first channel, and the gas supply device provides gas solvent to the first channel. Feed powder enters the first channel 108 from the sample delivery port 101, and the gas solvent enters the first channel 108 from the gas supply port 102. When ionizing the powder, the powder needs to be dissolved in the gas solvent so that the powder can be diffused more evenly in the first channel 108, which is conducive to the ionization operation. In this embodiment, nitrogen is used as the gas solvent because nitrogen has extremely high stability. Nitrogen will not be ionized during the ionization of the powder, and will not affect the final detection result.

[0027] Step 4: The ionization device in the first channel ionizes sample ions from the feed powder based on the ionization parameters, and the sample ions enter the second channel, and the remaining feed powder and gas solvent return to the detection branch. Figure 5 As shown, the ionization device 109 includes a vacuum ultraviolet krypton lamp 103 and an ionization zone. The vacuum ultraviolet krypton lamp 103 is installed on the left side of the ionization zone, and its light window is opposite to the central small hole of the first hole electrode 106 to ensure that the light beam passes through the entire ionization zone. The ionization zone is located between the vacuum ultraviolet krypton lamp 103 and the first hole electrode 106, and a driving electrode 105 and three transmission electrodes 104 are arranged in sequence from left to right. A DC voltage is applied to the driving electrode 105 and the first hole electrode 106 to form a uniform DC electric field on the central axis of the ionization zone. The electric field is an ionization electric field, which can drive the ionized feed powder ions to the second channel 208.

[0028] In order to ensure the sensitivity of the instrument during the ionization process, it is necessary to increase the injection amount of the sample to be tested and the gas solvent, which will cause the gas pressure in the first channel 108 to remain at a relatively high state. The interior of the migration device 310 needs to be in a high vacuum environment to ensure that the ions have a sufficient free path and do not collide with neutral gas molecules during the flight process, thereby affecting the flight time of the ions. Therefore, in order to ensure that the interior of the migration device 310 is in a high vacuum environment, the entire system needs to be evacuated. In this embodiment, the first suction device 110 is used to extract the remaining feed powder and gas solvent from the ionization device 109, and the second suction device 209 is used to extract the gas solvent in the transmission device and the migration device.

[0029] Step 5: The transmission device in the second channel modulates the sample ions into an ion beam and drives the ion beam into the third channel. Figure 6 As shown, the transmission device 207 is divided into two parts, a radio frequency transmission area 201 and an electrostatic transmission area 204 , by the first hole electrode 106 , the second hole electrode 202 , and the slit 206 .

[0030] There is a quadrupole in the RF transmission area 201. The quadrupole 203 is composed of four cylindrical electrodes parallel to each other and arranged symmetrically. By applying RF voltages with opposite phases to two opposite cylindrical electrodes, a periodic RF electric field is formed inside the quadrupole 203. When the ion beam enters the RF transmission area 201 from the ionization area, it will gradually gather on the central axis of the quadrupole 203 in space under the action of the RF electric field, reducing the initial spatial divergence and initial energy divergence of the ion beam, and having a cooling and focusing effect on the ion beam. Under the action of the DC electric field formed by the voltage difference between the first aperture electrode 106 and the second aperture electrode 202, the ion beam is driven to the electrostatic transmission area 204.

[0031] There is a flat lens in the electrostatic transmission area 204. The flat lens is an ion lens formed by an electrostatic field, and its effect on ions is similar to the effect of a convex lens on a light beam in an optical system. In this embodiment, the flat lens is composed of four rectangular flat electrodes 205, in which the same voltage is applied to the first and last electrodes, and another same voltage is applied to the middle two electrodes. The central potential of the middle two electrodes and the first and last electrodes constitute a two-dimensional single lens system. After the ion beam is cooled and focused by the quadrupole 203, the energy and angle divergence are small. After passing through the electrostatic transmission area 204, the speed of the ion beam in the vertical direction is further weakened under the action of the flat lens, and the divergence angle is further reduced, and multiple ions are compressed into a parallel ion beam with a rectangular cross-sectional area. Driven by the electric field formed by the voltage difference between the second aperture electrode 202 and the slit 206, the ion beam is driven to the third channel 308.

[0032] Step 6: Apply pulse voltage to the repelling device, and the matrix ions and the ions of the component to be measured in the ion beam pass through the repelling device and the migration device respectively and enter the analysis device. There is a repelling device and a migration device in the third channel. Figure 7 As shown, the repelling device 309 includes a repelling region 302 and an accelerating region 303, and the repelling region 302 has a repelling electrode 301. When the ion beam passes through the slit 206 and enters the third channel 308, a pulse voltage is applied to the repelling electrode 301, and an electric field is formed between the repelling electrode and the electrode grid, which can repel the ion beam into the accelerating region 303, and then the electric field of the accelerating region 303 is formed under the voltage difference between the electrode grids, so that the matrix ions and the component ions to be measured pass through the migration device 310 at the first flight speed v1 and the second flight speed v2 respectively.

[0033] like Figure 8 As shown, the migration device 310 includes a field-free channel 304, a first reflection area 305, and a second reflection area 306. The migration device 310 has a reflection electrode 307. Under the action of different voltages of the electrode grid and the reflection electrode 307, an electric field is formed in the first reflection area 305 and the second reflection area 306, and there is no electric field in the field-free channel. When the matrix ions and the component ions to be measured enter the migration device 310, since the electric field of the electrode grid is 0, the ions continue to maintain the original speed in the field-free channel. When entering the first reflection area 305 and the second reflection area 306, the ions will return to the field-free channel 304 under the action of the electric field. In this process, the speed of the matrix ions and the component ions to be measured in the horizontal direction remains unchanged, and the speed in the vertical direction is first reduced to 0 and then returns to the original speed, but in the opposite direction.

[0034] Step 7: Start the analysis device at the starting time t0, and the analysis device receives the matrix ions at the first collection time t1 and receives the component ions to be measured at the second collection time t2. The analysis device 311 is used to collect and amplify the ion signals and then transmit them to the data processing device 312. A mass spectrum is generated based on the intensity of the ion signals received starting from the starting time t0. In order to prevent the high-frequency signal from being reflected during the transmission process, it is necessary to set the impedance value of the load to match the internal impedance of the power supply. The data processing device 312 is started synchronously with the analysis device 311, receives the ion signals processed by the analysis device 311 and converts them into pulse signals, and then compares the pulse signals with the preset threshold value to draw a mass spectrum with the flight time as the horizontal coordinate and the ion signal intensity of each mass-to-charge ratio as the vertical coordinate, as shown in FIG. Fig. 9 shown.

[0035] In the present invention, the proportion of the matrix is ​​large and the content is stable. The present invention determines the signal intensity of the matrix according to the relationship between the base content of the matrix and the signal intensity. The first acquisition time t1 is the basis for adjusting other time parameters to prevent other fragment ions from interfering with the judgment of the acquisition time. The signal intensity of the matrix is ​​determined according to the base content of the matrix, and the moment with the signal intensity is found from the mass spectrum as the first acquisition time t1. The ions corresponding to the other various second acquisition times t2 in the mass spectrum are the component ions to be measured.

[0036] Step 8: Calculate the calibration acquisition time t3 according to the mass-to-charge ratio of the matrix ions, and then calibrate the activation time t4 according to the first acquisition time t1 and the calibration acquisition time t3. Fig.10 , Fig.11 As shown, a detection cycle includes sample delivery, ionization, flight and other stages. In the continuous detection of the present invention, the set start time is equal to the initial activation time, but as the working time of the repulsion device 309 and the analysis device 311 passes, sampling drift will occur between adjacent detection cycles, making the set start time and the activation time differ too much, affecting the flight time detection. In order to reduce the impact of sampling drift on the detection results in step 9, the activation time needs to be calibrated.

[0037] The theoretical flight time t of the matrix ion is calculated according to the mass-to-charge ratio of the matrix ion and the relationship between the mass-to-charge ratio and the flight time of the ion in Example 3, and then the calibration acquisition time t3=t0+t is determined in combination with the starting time t0. The sampling drift Δt=t1-t3 is calculated according to the time difference between the first acquisition time t1 and the calibration acquisition time t3, and then the activation time t4=t0+Δt is calculated according to the starting time t0.

[0038] Step 9: Calculate the mass-to-charge ratio of the component ion to be measured according to the second acquisition time t2, generate the measured content of the component to be measured according to the signal intensity at the second acquisition time t2, output the mass-to-charge ratio and the measured content of the component to be measured, and return to step 2.

[0039] The flight time t2-t4 of the component ion to be measured is obtained based on the difference between the second acquisition time t2 and the activation time t4 in the mass spectrum. The calibrated activation time t4 refers to the actual excitation time of the pulse voltage in the repulsion device 309. The mass-to-charge ratio of the component ion to be measured collected at the second acquisition time t2 is calculated based on the flight time of the component ion to be measured and the relationship between the mass-to-charge ratio of the ion and the ion flight time in Example 3, and then the molar mass is determined. Specifically, in the process of ionization of the feed component molecule in this embodiment, the feed component molecule will lose an electron and become an ion with a unit positive charge. The mass of the electron can be ignored. Therefore, the mass of the ion is equal to the molecular mass, and the molecular mass can be obtained by calculating the mass of the ion. Therefore, the mass-to-charge ratio of the component ion to be measured is multiplied by the charge number 1 to obtain the mass of the component ion to be measured. Since the mass of the ion is equal to the molecular mass, the molecular mass of the component to be measured can be obtained, and the molecular mass of different components is different. Then, the obtained molecular mass of the component to be measured is multiplied by the Avogadro constant to obtain the molecular molar mass of the component to be measured. The Avogadro constant N A Take 6.02×10 23 , and then determine the type of component to be tested based on the molar mass.

[0040] The response ratio η of a certain component refers to the ratio of the signal intensity σ corresponding to the component to the total signal intensity σ0 in the mass spectrum, that is, η=σ / σ0. Collect the response ratios at multiple different calibrated contents, establish a coordinate system with the response ratio η as the horizontal axis and the content λ as the vertical axis, and mark the response ratio of the component and the corresponding calibrated content in the coordinate system. Use the relevant fitting algorithm to fit these points into a smooth curve to obtain the relationship between the content λ and the response ratio η, that is, the response function λ=f(η). The response function is only related to the characteristics of the system itself. The present invention does not limit the relevant fitting algorithm. This embodiment uses the least squares method for fitting. The fitting result is as shown in the figure. Fig.12 The signal intensity σ at the second acquisition time t2 is read in the mass spectrum and its ratio σ / σ0 to the total signal intensity σ0 is calculated to obtain the response ratio η of the component to be tested, which is substituted into the response function λ=f(η) to obtain the actual measured content of the corresponding component to be tested in the feed. Embodiment 3

[0041] This embodiment further discloses a preferred method for calculating the mass-to-charge ratio of the present invention.

[0042] The relationship between the length and field strength of each part of the repelling device 309 and the migration device 310 and the starting position of the ion beam are as follows: Fig.13As shown. L1, L2, L3, L4, L5 represent the lengths of the repulsion zone 302, the acceleration zone 303, the field-free channel 304, the first reflection zone 305, and the second reflection zone 306, respectively, and E1, E2, E3, E4, E5 represent the electric field strengths of the repulsion zone 302, the acceleration zone 303, the field-free channel 304, the first reflection zone 305, and the second reflection zone 306, respectively. Z is the distance between the starting position of the ion in the repulsion zone 302 and the electrode grid, and z is numerically the same as the distance from the slit 206 to the electrode grid. Since the mass of a single ion is small and the flight time is very short, the influence of gravity on the motion of the ions can be ignored, and E3 is the field strength of the field-free channel 304, so E3=0.

[0043] Assume t5, t6, t7, t8, and t9 are the times of the ions moving in the five fields during their ascent, the ion mass is m, and the charge carried is q. When the ions enter the third channel 308, their vertical speed is first accelerated by the repulsion zone 302 and the acceleration zone 303. When the ions enter the field-free channel 304, they maintain a constant speed, and then they are decelerated to 0 under the action of the first reflection zone 305 and the second reflection zone 306, and then accelerated in the opposite direction. When they enter the field-free channel 304 again, they maintain a constant speed until the ions enter the analysis device 311. However, their horizontal speed remains unchanged during the flight. The following relationship can be obtained based on the ion movement relationship: ; ; ; ; .

[0044] Since the longitudinal flight trajectories in the migration device 310 are equivalent upward and downward, the flight time t of the ions after entering the third channel 308 and flying to the analysis device 311 is 10 =t5+t6+2(t7+t8+t9), by substituting into the above expressions of t5, t6, t7, t8, t9, we can get the relationship between the mass-to-charge ratio and the flight time of the ion. Then, the mass-to-charge ratio of the component ion to be measured can be determined based on the flight time t2-t4.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An online continuous detection system for feed ingredients, characterized in that: include: Detection branch, grinding device, pre-inspection device, sample delivery device, gas supply device, ionization device, transmission device, repulsion device, migration device, analysis device, data processing device, first calibration device, second calibration device, wherein, The detection branch is configured to receive feed particles from a conveyor belt; The grinding device is configured to form feed powder from feed particles; The pre-check device is configured to measure the current moisture content of the feed powder; The sample delivery device is configured to provide feed powder to the first channel; The gas supply device is configured to provide a gas solvent to the first channel; The ionization device is configured to ionize sample ions from the feed powder and drive the ions into the second channel; The transmission device is configured to modulate the sample ions into an ion beam and drive the ion beam into the third channel; The repeller is configured to adjust the flight speed of the ion beam; The migration device is configured to direct the ion beam into the analysis device; The analysis device is configured to receive matrix ions and analyte ions in the ion beam; The data processing device is configured to detect the measured content of the matrix and the measured content and mass-to-charge ratio of the component to be measured; The first calibration device is configured to calibrate an ionization parameter of the ionization device according to the current humidity of the feed powder; The second calibration device is configured to calibrate the activation time of the analysis device according to the measured content of the matrix.

2. The online continuous detection system of feed ingredients according to claim 1, characterized in that: It also includes a first suction device and a second suction device, the first suction device is configured to extract the remaining feed powder and the gas solvent from the ionization device, and the second suction device is configured to extract the gas solvent from the transmission device and the migration device.

3. An online continuous detection method using the online continuous detection system of feed ingredients as claimed in claim 1, characterized in that: The following steps are involved: Step 1: A conveyor belt continuously transports feed particles, the conveyor belt is connected to a detection branch, a grinding device and a pre-detection device are sequentially arranged in the detection branch, and the feed particles have a matrix and at least one component to be detected; Step 2: The grinding device makes feed particles into feed powder, the pre-detection device measures the current humidity of the feed powder, and calibrates at least one ionization parameter of the ionization device according to the current humidity; Step 3: The sample delivery device inhales feed powder from the detection branch and provides the feed powder to the first channel, and the gas supply device provides gas solvent to the first channel; Step 4: the ionization device in the first channel ionizes sample ions from the feed powder based on the ionization parameters, the sample ions enter the second channel, and the remaining feed powder and gas solvent return to the detection branch; Step 5: The transmission device in the second channel modulates the sample ions into an ion beam and drives the ion beam into the third channel; Step 6: applying a pulse voltage to the repelling device, and the matrix ions and the component ions to be measured in the ion beam pass through the repelling device and the migration device respectively and enter the analysis device; Step 7: starting the analysis device at the start time t0, the analysis device receives the matrix ions at the first collection time t1 and receives the component ions to be measured at the second collection time t2; Step 8: Calculate the calibration acquisition time t3 according to the mass-to-charge ratio of the matrix ions, and then calibrate the activation time t4 according to the first acquisition time t1 and the calibration acquisition time t3; Step 9: Calculate the mass-to-charge ratio of the component ion to be measured according to the second acquisition time t2, generate the measured content of the component to be measured according to the signal intensity at the second acquisition time t2, output the mass-to-charge ratio and the measured content of the component to be measured, and return to step 2.

4. The online continuous detection method according to claim 3, characterized in that: The matrix is ​​one or more of vitamins, proteins or carbohydrates, the components to be detected are one or more of heavy metals, toxins or pesticides, and the gas solvent is nitrogen.

5. The online continuous detection method according to claim 3, characterized in that: In step 2, the ionization parameters include ionization temperature and electric field strength. The humidity difference between the current humidity and the calibrated humidity is calculated, the compensation temperature is calculated according to the humidity difference, and the ionization temperature is calculated according to the compensation temperature. If the ionization temperature is greater than the system linear temperature, the electric field strength of the ionization device is adjusted according to the ionization temperature and the pressure of the first channel.

6. The online continuous detection method according to claim 3, characterized in that: In step 6, the matrix ions and the component ions to be detected in the ion beam pass through the migration device at the first flight speed v1 and the second flight speed v2 respectively.

7. The online continuous detection method according to claim 3, characterized in that: In step 7, the signal intensity of the matrix is ​​determined according to the reference content of the matrix, and a time with the signal intensity is found as the first acquisition time t1.

8. The online continuous detection method according to claim 7, characterized in that: In step 8, the sampling drift Δt is calculated according to the first acquisition time t1 and the calibration acquisition time t3, and the activation time t4 = t0 + Δt.

9. The online continuous detection method according to claim 8, characterized in that: In step 9, the flight time of the component ion to be measured is determined according to the activation time t4 and the second acquisition time t2, and the mass-to-charge ratio and molar mass of the component ion to be measured are calculated according to the flight time of the component ion to be measured.

10. The online continuous detection method according to claim 9, characterized in that: In step 9, a response function is generated according to the response ratios at multiple different calibrated contents, and then the response ratio of the component to be measured at the second acquisition time t2 is calculated, and the actual measured content of the component to be measured is determined according to the response ratio and the response function.

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