Automated reconstitution and delivery control method and system for at-211 separation

Abstract

This invention relates to the field of radioactive separation technology, and discloses an automated solution preparation and delivery control method and system for At-211 separation, comprising: Step 1, determining the column bed volume, setting the minimum operating volume particle size, and determining the pump running time; Step 2, solidifying the reagent and matching it with the valve inlet, obtaining the background current and determining the low threshold current, high threshold current, tail threshold current, and volume confirmation rules for the buffer solution; Step 3, generating the loading solution; Step 4, delivering the low-acid washing column solution, buffer solution, and preset equilibration solution to obtain the separation column; Step 5, loading the sample and comparing the output current of the ionization chamber with the low threshold current and high threshold current to determine the three states; Step 6, switching the collection valve to the product bottle and cutting off the organic elution solvent; Step 7, controlling the collection valve and determining the actual product volume. This invention achieves automated and quantitative control of solution preparation, delivery, elution, and collection during the At-211 separation process.

Description

Technical Field

[0001] The present invention belongs to the technical field of radioactive separation, and particularly relates to an automated liquid preparation and transportation control method and system for At-211 separation. Background Art

[0002] At-211 is an α-emitting radioactive nuclide with important application value, and its preparation usually depends on bombarding a target with an accelerator. After the target is dissolved, a solution system containing At-211 is formed, and then the target nuclide needs to be separated and purified from the matrix metal and impurity components through a separation column. This process belongs to the wet separation process of radioactive metals and involves multiple continuous steps such as acidity adjustment, pre-column pretreatment, adsorption and elution, and product collection.

[0003] In the existing At-211 separation process, the solution preparation and flow path switching control mostly rely on manual experience. There is a lack of a unified quantitative benchmark between the column bed volume and the transportation volume, and the operation consistency between different batches is poor. At the same time, during the column washing and elution stages, the start and end of the product section are usually judged by manually observing the detection signal or a preset time window. It is difficult to form a quantitative coupling between the online detection signal and the transportation volume, and it is easily affected by instantaneous fluctuations or human judgment deviations, resulting in inaccurate product volume measurement and even the situation of mixed collection of products and tail liquids. In addition, the valve switching and solvent replacement actions often lack a linkage control logic, and the automation degree and repeatability of the separation process need to be improved. Summary of the Invention

[0004] The present invention provides an automated liquid preparation and transportation control method and system for At-211 separation, which solves the technical problems in the related art that it is difficult to accurately quantify the liquid preparation volume and the transportation volume, the reagent switching and the collection valve switching rely on manual timing, the online current criterion is easily affected by background drift and instantaneous fluctuations, resulting in unstable definition of the elution interface and the collection section, and poor consistency of separation and collection between batches.

[0005] The present invention provides an automated liquid preparation and transportation control method for At-211 separation, including the following steps:

[0006] Step 1, obtain the column bed volume of the separation column, set the minimum action volume granularity, and determine the pump operation duration according to the preset target volume;

[0007] Step 2, fix the dissolution target acid, low acid column washing solution, buffer solution, organic elution solvent and the inlets of the multi-inlet selection valve in one-to-one correspondence. Transport the buffer solution through the sampling cavity to obtain the background current, and determine the low threshold current, high threshold current and tail threshold current, and set the volume confirmation rule;

[0008] Step 3, determine the volume of the dissolution target acid added and the volume of the buffer solution based on the initial concentration of the dissolution target acid, the target acidity and the preset target volume, and generate the loading solution;

[0009] Step 4: Switch the flow path to the column inlet and sequentially deliver low acid washing solution, buffer solution and preset equilibration solution according to the preset column bed volume multiple to generate a pre-treated and equilibrated column.

[0010] Step 5: Deliver the sample solution at a preset fixed sample flow rate, obtain the output current of the ionization chamber, and compare it with the low threshold current and the high threshold current. Combine the volume confirmation rules to determine the no-product state, product-ready state, or forced product state.

[0011] Step 6: After the sample loading is completed, a column washing gradient is formed according to the preset column bed volume multiple. When the output current of the ionization chamber is higher than the high threshold current and the volume confirmation rule is met, the collection valve is switched to the product bottle and the organic elution solvent is switched.

[0012] Step 7: Perform elution at a fixed organic elution flow rate according to the elution bag volume, obtain the output current of the ionization chamber and compare it with the low threshold current, high threshold current and tail threshold current, control the switching of the collection valve in combination with the volume confirmation rules, and determine the actual product volume.

[0013] The present invention also includes an automated liquid preparation and delivery control system for At-211 separation, comprising:

[0014] The column bed quantitative module is used to obtain the column bed volume of the separation column, set the minimum operating volume particle size, and determine the pump running time based on the preset target volume;

[0015] The threshold criterion module is used to fix the target acid, low acid washing solution, buffer solution, organic elution solvent and the inlet of the multi-inlet selector valve one by one, deliver the buffer solution through the sampling chamber to obtain the background current, and determine the low threshold current, high threshold current and tail threshold current, and set the volume confirmation rules.

[0016] The sample preparation module is used to determine the volume of target acid to be added and the volume of buffer solution based on the initial concentration of target acid, target acidity and preset target volume, and to generate the sample preparation solution.

[0017] The column pretreatment module is used to switch the flow path to the separation column inlet and sequentially deliver low acid washing solution, buffer solution and preset equilibration solution according to a preset column bed volume multiple to generate a separation column that has completed pretreatment and equilibration.

[0018] The sample loading determination module is used to deliver the sample loading solution at a preset fixed sample loading flow rate, obtain the output current of the ionization chamber, and compare it with the low threshold current and the high threshold current. Combined with the volume confirmation rule, it determines the no-product state, the product preparation state, or the forced product state.

[0019] The column washing linkage module is used to form a column washing gradient according to a preset column bed volume multiple after sample loading. When the output current of the ionization chamber is higher than the high threshold current and meets the volume confirmation rule, the collection valve is switched to the product bottle and the organic elution solvent is switched.

[0020] The elution and collection module is used to perform elution at a fixed organic elution flow rate according to the elution bag volume, obtain the output current of the ionization chamber and compare it with the low threshold current, high threshold current and tail threshold current, control the switching of the collection valve in combination with the volume confirmation rules, and determine the actual product volume.

[0021] The beneficial effects of this invention are as follows: This invention establishes a volume regularization mechanism based on column bed volume, focusing on key aspects such as solution ratio control, volume measurement consistency, and elution stage stability in the At-211 separation process. It also achieves discretized control of solution volume and delivery volume by combining minimum action volume granularity, ensuring consistent solution volume across different batches at each stage. Regarding detection and switching control, low-threshold current, high-threshold current, and tail-threshold current are generated based on background current, and volume confirmation rules are introduced. Combining current amplitude determination with cumulative delivery volume provides clear criteria for product segment identification and collection valve switching. Furthermore, synchronous recording of the collection valve pointing state and cumulative delivery volume during the elution stage accurately determines the actual product volume. These technical solutions reduce manual intervention, improve the stability and repeatability of the separation process, and enhance the controllability of the At-211 separation operation. Attached Figure Description

[0022] Figure 1 This is a flowchart of the automated liquid preparation and delivery control method for At-211 separation according to the present invention. Detailed Implementation

[0023] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0024] like Figure 1 As shown, an automated solution preparation and delivery control method for At-211 separation includes the following steps:

[0025] Step 1: Obtain the column bed volume of the separation column, set the minimum action volume particle size, and determine the pump running time based on the preset target volume;

[0026] Step 2: Fix the target acid, low acid washing column solution, buffer solution, organic elution solvent and the inlet of the multi-inlet selector valve one by one, deliver the buffer solution through the sampling chamber to obtain the background current, and determine the low threshold current, high threshold current and tail threshold current, and set the volume confirmation rules.

[0027] Step 3: Determine the volume of target acid to be added and the volume of buffer solution based on the initial concentration of target acid, target acidity and preset target volume to generate the loading solution;

[0028] Step 4: Switch the flow path to the column inlet and sequentially deliver low acid washing solution, buffer solution and preset equilibration solution according to the preset column bed volume multiple to generate a pre-treated and equilibrated column.

[0029] Step 5: Deliver the sample solution at a preset fixed sample flow rate, obtain the output current of the ionization chamber, and compare it with the low threshold current and the high threshold current. Combine the volume confirmation rules to determine the no-product state, product-ready state, or forced product state.

[0030] Step 6: After the sample loading is completed, a column washing gradient is formed according to the preset column bed volume multiple. When the output current of the ionization chamber is higher than the high threshold current and the volume confirmation rule is met, the collection valve is switched to the product bottle and the organic elution solvent is switched.

[0031] Step 7: Perform elution at a fixed organic elution flow rate according to the elution bag volume, obtain the output current of the ionization chamber and compare it with the low threshold current, high threshold current and tail threshold current, control the switching of the collection valve in combination with the volume confirmation rules, and determine the actual product volume.

[0032] In one embodiment of the present invention, to ensure the volume consistency and repeatability of mass transfer behavior and adsorption-elution processes of various solutions within the separation column during the At-211 separation process, the effective liquid containment space of the separation column is first quantitatively calculated; the column bed volume of the separation column is obtained, the minimum operating volume particle size is set, and the pump running time is determined based on the preset target volume, including:

[0033] Step 11: Obtain the inner diameter, column bed height, and column bed porosity of the separation column. Using half the inner diameter as the radius, calculate the circular cross-sectional area of ​​the separation column. Multiply the circular cross-sectional area by the column bed height to obtain the column volume. Since the column volume includes the volume of the packing particles and the void volume between the particles, to obtain the effective volume available for liquid flow, multiply the column volume by the column bed porosity to obtain the column bed volume. The separation column refers to a packed column used for the separation of radioactive metals, filled with solid-phase adsorption material. The column bed volume refers to the effective volume occupied by fluid between the packing particles, which directly determines the residence time of the solution in the column and the adsorption equilibrium state. The column bed porosity is the ratio of the void volume between the packing particles to the total column volume.

[0034] Step 12: Determine the minimum action volume particle size according to the preset minimum action volume particle size generation rule. The minimum action volume particle size refers to the smallest volume unit allowed for all pumping and dispensing operations in the system, used for discretized control of continuous volume. The preset minimum action volume particle size generation rule refers to a rule pre-set based on the column bed volume and equipment metering accuracy, used to determine the volume discrete unit suitable for the current separation column size. After determining the minimum action volume particle size based on the column bed volume, divide the subsequent dispensing volume and delivery volume by the minimum action volume particle size and round to the nearest integer as the normalization factor. Then multiply the normalization factor by the minimum action volume particle size to obtain the normalized dispensing volume and the normalized delivery volume. Through this volume normalization process, all solution volumes entering the separation column are integer multiples of the uniform particle size, thereby ensuring volume consistency between different batch operations and avoiding shifts in the distribution of At-211 within the column and the position of the elution interface due to minor volume errors.

[0035] Step 13: Obtain the preset target volume and preset fixed pump flow rate. The preset target volume refers to the theoretical volume value to be delivered to the separation column in this operation plan; the preset fixed pump flow rate refers to the constant volumetric flow rate parameter set by the system, used to control the liquid delivery speed. The pump running time is obtained by calculating the ratio of the preset target volume to the preset fixed pump flow rate. This pump running time is sent as a control signal to the delivery pump, ensuring that the pump runs for the corresponding duration under fixed flow conditions to complete the delivery of the target volume. By converting volume control to time control, real-time feedback adjustment of instantaneous flow rate is avoided, making the liquid delivery in the At-211 separation process deterministic and traceable.

[0036] Through the above implementation methods, the present invention establishes a volume discretization and time-equivalent control mechanism with column bed volume as the core benchmark in the At-211 separation process. This enables the preparation volume, washing volume, and elution volume to be uniformly planned with column bed volume as the scale, and achieves precise regularization through minimum action volume granularity. This results in stable and repeatable liquid propulsion and interface control in radioactive metal separation operations.

[0037] In one embodiment of the present invention, the target acid, low-acid washing solution, buffer solution, organic elution solvent, and multi-inlet selector valve inlet are fixed one-to-one. The buffer solution is delivered through the sampling chamber to obtain the background current, and the low threshold current, high threshold current, and tail threshold current are determined. Volume verification rules are set, including:

[0038] Step 21: Obtain the inlet number of the multi-inlet selection valve and a list of preset reagent names. The multi-inlet selection valve refers to a flow path switching device with multiple independent inlet channels that can switch the connection between different inlets and a common outlet under the action of a control signal. The list of preset reagent names includes target acid, low-acid washing solution, buffer solution, and organic elution solvent. The above reagents are then mapped one-to-one with the specific inlet number of the multi-inlet selection valve, forming an inlet mapping. Inlet mapping refers to the fixed correspondence between reagent names and specific inlet numbers of the multi-inlet selection valve. Through inlet mapping, the system control program can directly call the corresponding inlet number based on the reagent name, avoiding the risk of incorrect switching due to manual confirmation, thereby ensuring the consistency of solution type and delivery path during the At-211 separation process.

[0039] Step 22: Switch to the corresponding inlet of the buffer solution according to the inlet mapping, and deliver the buffer solution through the sampling chamber at a preset flow rate, allowing the buffer solution to flow through the ionization chamber detection area. The sampling chamber is a detection channel located at the front end or in the middle flow path of the separation column, used to allow the fluid to pass through the ionization chamber detection area. Since the buffer solution does not contain the target radionuclide At-211 at this stage, the ionization chamber output current mainly reflects the inherent noise of the system, the background response of the ionization chamber, and the contribution of fluid conductivity. The ionization chamber output current obtained during buffer solution delivery is continuously sampled to form an ionization chamber output current sampling sequence, and the minimum sampled value in the sampling sequence is determined as the background current. The background current refers to the reference current value generated when the fluid passes through the ionization chamber under conditions without At-211. By using the buffer solution data under actual operating conditions as a reference, the influence of equipment differences, temperature changes, and flow path residues on threshold judgment is eliminated, making subsequent judgments adaptive to the current system state.

[0040] Step 23: After obtaining the background current, acquire the preset threshold generation rule and the volume confirmation rule. The preset threshold generation rule is used to generate different judgment level current thresholds based on the background current; the preset low threshold current increment, preset high threshold current increment, and preset tail threshold current increment are current difference parameters relative to the background current, used to distinguish different stages of radioactive signals; the volume confirmation rule refers to the rule that the threshold comparison result is considered a valid judgment result only when the cumulative transport volume reaches the preset confirmation volume. According to the preset threshold generation rule, the background current is added to the preset low threshold current increment to obtain the low threshold current, the background current is added to the preset high threshold current increment to obtain the high threshold current, and the background current is added to the preset tail threshold current increment to obtain the tail threshold current. In this way, each threshold current is generated with an offset based on the actual background current, thereby ensuring that the threshold matches the current system noise level.

[0041] Simultaneously, reaching a preset confirmation volume is used as the effective condition for the volume confirmation rule. The cumulative delivery volume refers to the cumulative volume formed by delivering solution at a fixed flow rate during a specific operation phase; the preset confirmation volume is the minimum volume threshold used to prevent misjudgments triggered by instantaneous current fluctuations. The threshold comparison result is only confirmed and effective when the cumulative delivery volume reaches the preset confirmation volume. By combining the current criterion with the volume confirmation rule, the judgment of the current signal during the At-211 separation process is subject to both amplitude and volume constraints, avoiding malfunctions of the collection valve due to short-term fluctuations or trace residues.

[0042] Through the above implementation methods, the present invention establishes an adaptive threshold system based on actual background current during the At-211 separation process, and introduces a judgment threshold of volume dimension through volume confirmation rules, so as to form a coupled control mechanism between radioactive signal identification and fluid transport process, improve the judgment accuracy and batch consistency of the automated separation process, and thus enhance the stable operation capability of the At-211 separation system.

[0043] In one embodiment of the present invention, the volume of target acid added and the volume of buffer solution are determined based on the initial concentration of the target acid, the target acidity, and the preset target volume to generate a sample loading solution, including:

[0044] Step 31: Obtain the initial concentration of the dissolving acid, the target acidity, and the preset target volume, and determine the validity of these parameters. The dissolving acid refers to the acidic solution used to dissolve the target material and release At-211; its acidity is typically higher than the target acidity required for loading onto the separation column. The initial concentration of the dissolving acid refers to its acidity parameter in its undiluted state. The target acidity refers to the acidity value required for the loading solution to enter the separation column. Validity determination includes confirming that the data has been collected and is within the allowable range, avoiding inaccurate solution ratios due to missing parameters or outliers. Subsequently, a volume particle size consistency check is performed on the preset target volume, i.e., determining whether the preset target volume is an integer multiple of the minimum action volume particle size. When the preset target volume meets the integer multiple constraint, the verified preset target volume is obtained. This check ensures that subsequent volume calculation results can directly match the discrete volume control capability of the automatic delivery system, avoiding inconsistencies between pump running time and the target volume due to non-integer multiple volumes.

[0045] Step 32: After obtaining the verified target volume, the volume is calculated according to the acidity conservation relationship. The target acidity is multiplied by the verified target volume to obtain a first result, which represents the amount of acid required under the target acidity condition. This first result is then divided by the initial concentration of the target acid to obtain the theoretical target acid addition volume. This calculation process is based on the quantitative relationship between solution concentration and volume, ensuring the sample solution reaches the target acidity. Subsequently, the target acid addition volume is divided by the minimum action volume granularity and rounded to the nearest integer as a normalization factor. This normalization factor is then multiplied by the minimum action volume granularity to obtain the normalized target acid addition volume. Through this normalization process, the theoretically calculated volume is converted into a standard volume unit that the system can execute.

[0046] Step 33: After determining the standardized target acid addition volume, subtract the standardized target acid addition volume from the verified preset target volume to obtain the buffer solution volume. The buffer solution is used to adjust the solution acidity and provide a suitable ionic environment; its addition volume also needs to be standardized. Divide the buffer solution volume by the minimum action volume particle size and round to the nearest integer as the standardization factor. Then multiply the standardization factor by the minimum action volume particle size to obtain the standardized buffer solution volume. By standardizing the volumes of the two solutions separately, it is ensured that the total volume of the final prepared loading solution remains within an integer multiple of the minimum action volume particle size.

[0047] Step 34: Switch the inlet mapping to the inlet corresponding to the target acid and deliver the solution according to the adjusted target acid volume. Then, switch the inlet mapping to the inlet corresponding to the buffer solution and deliver the solution according to the adjusted buffer volume. Deliver the target acid and buffer solution to the same target container and mix them to form the loading solution. The target container is a closed container used for temporary storage and mixing of the components, ensuring uniform solution composition.

[0048] Through the above embodiments, the present invention establishes a quantitative solution preparation mechanism with target acidity as the control core in the At-211 separation process, and achieves automated regularization control by combining minimum action volume particle size, so that the acidity and volume of the sample solution are consistent between different batches, improving the stability and repeatability of sample loading conditions, and reducing the difference in separation efficiency caused by acidity fluctuations.

[0049] In one embodiment of the present invention, the flow path is switched to the inlet of the separation column, and low-acid washing solution, buffer solution, and preset equilibration solution are sequentially delivered according to a preset column bed volume multiple to generate a separation column that has completed pretreatment and equilibration, including:

[0050] Step 41: Obtain the column bed volume, minimum action volume granularity, and preset column bed volume multiple sequence. Multiply each preset column bed volume multiple in the preset column bed volume multiple sequence by the column bed volume to obtain the corresponding preset delivery volume. The preset column bed volume multiple sequence refers to several proportional coefficients set based on the column bed volume, used to determine the delivery volume of the washing solution at each stage; the preset delivery volumes correspond to the delivery volumes of low-acid washing solution, buffer solution, and equilibration solution, respectively. Subsequently, a volume granularity consistency check is performed on each preset delivery volume, i.e., to confirm whether each preset delivery volume is an integer multiple of the minimum action volume granularity. When the integer multiple constraint is met, the preset delivery volume is confirmed for subsequent delivery control. Through this process, all liquid volumes entering the separation column are uniformly planned using the column bed volume as the proportional unit, and are consistent with the system's metering accuracy.

[0051] Step 42: After determining the volume parameters, switch the flow path to the separation column inlet and point the separation column outlet towards the waste liquid. The flow path switching refers to changing the liquid channel through a multi-inlet selection valve or other valve control device to allow liquid to enter the separation column; pointing the separation column outlet towards the waste liquid means directing the outflowing liquid into a waste liquid container to prevent the pretreatment solution from entering the product collection path. Subsequently, the inlet mapping is invoked, sequentially switching to the corresponding inlets for the low-acid wash solution, buffer solution, and equilibration solution, and delivering them according to their respective preset delivery volumes. The low-acid wash solution is used to remove residual strong acid or impurities within the column, the buffer solution is used to adjust the acidity gradient within the column, and the equilibration solution is used to establish stable sample loading conditions. By sequentially delivering solutions of different properties, the internal environment of the separation column gradually transitions to the desired chemical state.

[0052] Step 43: After each stage of delivery is completed, acquire the delivery completion status of the low-acid wash solution, buffer solution, and equilibration solution. The delivery completion status refers to the state signal indicating that the corresponding liquid has reached the preset delivery volume and the pump has run for the set duration. Subsequently, with the separation column outlet pointing towards the waste liquid, perform a consistency judgment on the three delivery completion statuses according to the preset delivery sequence, confirming that the completion sequence is consistent with the preset sequence and that all have reached the corresponding volume requirements. When the consistency judgment passes, generate a separation column status flag indicating that pretreatment and equilibration are complete, signifying that the internal environment of the separation column has reached the conditions for sample loading.

[0053] Through the above embodiments, the present invention establishes a segmented pretreatment and equilibration control mechanism based on column bed volume in the At-211 separation process, so that the delivery volume of low acid washing solution, buffer solution and equilibration solution matches the actual effective volume of the separation column, and ensures the complete execution of the pretreatment steps through sequential consistency judgment, thereby improving the repeatability and separation efficiency of the sample loading stage.

[0054] In one embodiment of the present invention, a sample solution is delivered at a preset fixed sample loading flow rate, the output current of the ionization chamber is obtained, and compared with a low threshold current and a high threshold current. Based on volume confirmation rules, a product-free state, a product-ready state, or a forced product state is determined, including:

[0055] Step 51: Obtain the preset fixed loading flow rate, loading solution, pre-treated and equilibrated separation column, low-threshold current, and high-threshold current. The preset fixed loading flow rate refers to the constant volumetric flow rate pre-set by the system, used to deliver the loading solution at a constant rate during the loading stage. The loading solution refers to the solution to be separated after being prepared with target acid and buffer solution to reach the target acidity condition. The pre-treated and equilibrated separation column refers to a separation column that has been sequentially treated with low-acid washing solution, buffer solution, and equilibration solution to meet the loading conditions. Subsequently, the loading solution is delivered into the pre-treated and equilibrated separation column at the preset fixed loading flow rate, allowing the solution to adsorb onto the solid-phase material within the column. During the loading process, the radioactivity signal of the effluent is continuously detected in the ionization chamber to obtain the ionization chamber output current sampling sequence, and the loading time is recorded simultaneously. Since the flow rate remains constant, the loading time and flow rate together determine the cumulative delivery volume.

[0056] Step 52: After acquiring the ionization chamber output current sampling sequence, each sampled value in the sampling sequence is compared with the low threshold current and the high threshold current, respectively, to obtain a threshold comparison result sequence. This comparison result is used to reflect the degree of change of the At-211 signal in the current effluent relative to the background level. Simultaneously, the product of the preset fixed sample loading flow rate and the sample loading and delivery time is determined as the cumulative delivery volume. A volume confirmation rule and a preset confirmation volume are obtained; when the cumulative delivery volume reaches the preset confirmation volume, that moment is taken as the effective threshold. By introducing a volume confirmation rule, the threshold comparison result is only confirmed as valid after a certain delivery volume is reached, thereby avoiding interference from instantaneous fluctuations on the judgment result.

[0057] Step 53: When the cumulative transport volume corresponding to the threshold comparison result sequence reaches the effective threshold, the corresponding threshold comparison result is recorded as the confirmed comparison result sequence, and the current operating state is determined according to the preset state mapping rule. The preset state mapping rule refers to the rule that establishes a one-to-one correspondence between the confirmed comparison results and three operating states. Specifically, when the confirmed comparison result is below the low threshold current, it is determined to be in the no-product state, indicating that no obvious At-211 signal was detected in the effluent; when the confirmed comparison result is between the low and high threshold currents, it is determined to be in the product preparation state, indicating that the At-211 signal has begun to appear but has not yet reached a high intensity level; when the confirmed comparison result is above the high threshold current, it is determined to be in the forced product state, indicating that the At-211 signal in the effluent has reached a relatively high intensity level. Through the above state division, the system can automatically identify different stages based on the intensity of the radioactive signal.

[0058] The method described in this embodiment realizes an online determination mechanism based on the output current of the ionization chamber during the At-211 separation process. By combining the current amplitude with the volume confirmation rule, the determination result has both signal strength basis and volume threshold constraint, thereby improving the accuracy of automated control of the separation process. This helps to realize real-time monitoring and status classification of At-211 adsorption behavior in automated liquid preparation and delivery control systems, and improves the consistency and repeatability of separation operations.

[0059] In one embodiment of the present invention, after sample loading, a column washing gradient is formed according to a preset column bed volume multiple. When the output current of the ionization chamber is higher than the high threshold current and the volume confirmation rule is met, the collection valve is switched to the product bottle and the organic elution solvent is switched, including:

[0060] Step 61: After the sample loading stage, the system first acquires the high threshold current, the preset confirmation volume, and the cumulative delivery volume, and continuously acquires the ionization chamber output current. The cumulative delivery volume refers to the cumulative volume value formed by delivering the solution at a fixed flow rate during the current operation stage. The ionization chamber output current is compared with the high threshold current to obtain the high threshold comparison result; simultaneously, it is determined whether the cumulative delivery volume has reached the preset confirmation volume. When the cumulative delivery volume reaches the preset confirmation volume, the volume confirmation result is confirmed. This dual determination combines the validity of the current signal with the delivery volume condition, avoiding false triggering due to instantaneous fluctuations or residual signals.

[0061] Step 62: During the column washing gradient process, the system continuously acquires the high threshold comparison result and the volume confirmation result, and logically combines the two. When the high threshold comparison result shows that the ionization chamber output current is higher than the high threshold current, and the volume confirmation result is valid, this state is determined as the linkage switching trigger condition. Since the adsorption and desorption behavior of At-211 within the separation column causes changes in the radioactive signal in the effluent, when the signal reaches the high threshold level and continuously exceeds the volume confirmation threshold, it indicates that the radioactive material within the separation column has begun to enter the elution stage. The column washing gradient refers to the process of gradually transitioning the column environment from the sample loading state to the elution state by sequentially changing the composition or acidity conditions of the solution entering the separation column according to a preset column bed volume multiple.

[0062] Step 63: When the linkage switching trigger condition is met, the system executes synchronous control actions. On the one hand, it switches the collection valve to the product bottle, allowing the subsequent effluent to enter the product collection path; on the other hand, it calls the inlet mapping to switch to the inlet corresponding to the organic elution solvent, so that the solution entering the separation column transitions from the washing liquid to the organic elution solvent. The collection valve refers to the valve control device used to control the direction of the fluid at the separation column outlet, and the product bottle is the container used to collect the target nuclide solution. The linkage switching trigger condition refers to the control condition that triggers the synchronous switching of the collection valve and the solvent inlet when both the current criterion and the volume criterion are met. Through the above linkage control, the switching of the collection path and the elution solvent is completed under the same trigger condition, avoiding the mixing of product solution with waste liquid or washing liquid due to asynchronous operation.

[0063] Through the method described in this embodiment, the present invention establishes a linkage control mechanism in the At-211 separation process, with the ionization chamber output current as the core criterion and the volume confirmation rule as the auxiliary constraint, realizing the automatic transition from the column washing stage to the elution stage; by coupling the online detection signal with the volume condition, the key switching nodes in the separation process have clear and repeatable triggering criteria, thereby improving the stability and operational consistency of the automated liquid preparation and delivery control system used for At-211 separation.

[0064] In one embodiment of the present invention, elution is performed at a fixed organic elution flow rate based on the elution bag volume. The output current of the ionization chamber is obtained and compared with the low threshold current, high threshold current, and tail threshold current. The collection valve is switched in conjunction with the volume confirmation rule, and the actual product volume is determined, including:

[0065] Step 71: Obtain the fixed organic elution flow rate, elution pack volume, low threshold current, high threshold current, tail threshold current, volume confirmation rules, and preset confirmation volume. The fixed organic elution flow rate refers to the constant volumetric flow rate parameter maintained during the elution stage to ensure stable fluid propulsion speed during the elution process. The elution pack volume refers to the volume value corresponding to each unit when the elution process is divided into several equal volume units, used to form a volume benchmark for segmented detection and control. The tail threshold current refers to the lower limit of the current used to determine the end of the product segment. With the organic elution solvent switched to the separation column inlet via inlet mapping, the organic elution solvent is continuously delivered at a fixed organic elution flow rate according to the elution pack volume, causing At-211 adsorbed on the separation column packing to be gradually desorbed and enter the detection channel with the effluent. During the elution process, the effluent is continuously detected through the ionization chamber, forming an ionization chamber output current sampling sequence. Because the flow rate remains constant, each completed elution pack volume forms a corresponding detection cycle, establishing a one-to-one correspondence between volume and current signal.

[0066] Step 72: Each sampled value in the ionization chamber output current sampling sequence is compared with the low threshold current, high threshold current, and tail threshold current to obtain a threshold comparison result sequence. This threshold comparison result sequence is used to reflect the intensity range of the At-211 signal in the effluent. Simultaneously, the elution transport time is recorded, and the product of the fixed organic elution flow rate and the elution transport time is determined as the cumulative transport volume. A volume confirmation result is generated by determining whether the cumulative transport volume has reached the preset confirmation volume. By introducing a volume confirmation rule, the current judgment result is combined with the volume propagation process, avoiding misjudgments caused by instantaneous current fluctuations.

[0067] Step 73: When the volume confirmation result is valid, the current threshold comparison result sequence is recorded as the confirmed comparison result sequence, and the collection valve is controlled to switch between the product bottle and the tail liquid or waste liquid based on this confirmed comparison result sequence. When the confirmed comparison result sequence shows that the current is within the product range, the collection valve remains pointing towards the product bottle; when the confirmed comparison result sequence shows that the current is lower than the tail threshold current, the product segment is determined to have ended, and the collection valve is switched to the tail liquid or waste liquid path. Simultaneously, during the period when the collection valve is pointing towards the product bottle, the corresponding cumulative transport volume is recorded and accumulated, and the cumulative value is ultimately determined as the actual product volume; the actual product volume refers to the cumulative volume of solution entering the product bottle during the period when the collection valve is pointing towards the product bottle. Since the flow rate is constant, volume calculation and time measurement form an equivalent relationship, thereby achieving automated measurement of product volume.

[0068] Through the above embodiments, this invention achieves integrated control of elution, detection, collection, and volume measurement in the At-211 separation process. A volume reference is established by fixing the organic elution flow rate and elution bag volume. Segmented identification and valve control switching are achieved through three-threshold current judgment and volume confirmation rules. The actual product volume is determined by the correspondence between valve position status and cumulative delivery volume. This transforms the At-211 separation operation from manual experience-based judgment to an automatic control process based on signal and volume coupling, improving the stability, repeatability, and measurement accuracy of the separation system.

[0069] In one embodiment of the present invention, determining the actual product volume based on the cumulative conveyed volume during the period when the collection valve is pointing towards the product bottle includes:

[0070] Step 81: Obtain the current pointing state of the collection valve and the cumulative delivery volume. During the elution stage, when the current pointing state of the collection valve is the product bottle, the system records the current cumulative delivery volume and forms the cumulative delivery volume of the product bottle. Since the elution process is carried out under a fixed organic elution flow rate, the cumulative delivery volume and the elution delivery time maintain a corresponding relationship. Therefore, the cumulative delivery volume of the product bottle can accurately reflect the total volume of eluent entering the product bottle.

[0071] Step 82: Obtain the confirmed comparison result sequence. This confirmed comparison result sequence is a valid comparison result obtained after the volume confirmation rule is met, based on comparisons between the ionization chamber output current and the low threshold current, high threshold current, and tail threshold current. When the current pointing state of the collection valve is the product bottle, and the confirmed comparison result sequence shows that the ionization chamber output current is lower than the tail threshold current, a product segment end flag is generated, and the product segment end state is locked. By combining the current signal with the valve position state, a deterministic criterion for the end of the product segment is formed, preventing the continued miscollection of low-activity liquid into the product bottle during the radioactivity signal decay phase.

[0072] Step 83: After the product segment ends and the state is locked, the system disables the switching action of the collection valve switching command pointing to the product bottle. Even if there are short-term fluctuations in the subsequent current signal, the collection valve is no longer allowed to switch back to the product bottle path. This locking mechanism ensures that the collection path remains stable after the product segment ends. Finally, the cumulative transport volume of the product bottle recorded during the period when the collection valve is pointing to the product bottle is determined as the actual product volume and output as the measurement result of the separation operation.

[0073] Through the above embodiments, the present invention establishes a product volume determination mechanism based on valve position status, current criteria, and volume measurement in the elution and collection stage of At-211 separation. This mechanism can synchronously couple online detection results with the volume measurement process, giving the start and end of the product segment clear and repeatable judgment criteria. This improves the stability and measurement accuracy of the automated liquid preparation and delivery control system used for At-211 separation in the product collection stage, and enhances batch consistency of the separation operation.

[0074] In one embodiment of the present invention, an automated liquid preparation and delivery control system for At-211 separation is also provided, comprising:

[0075] The column bed quantitative module is used to obtain the column bed volume of the separation column, set the minimum operating volume particle size, and determine the pump running time based on the preset target volume;

[0076] The threshold criterion module is used to fix the target acid, low acid washing solution, buffer solution, organic elution solvent and the inlet of the multi-inlet selector valve one by one, deliver the buffer solution through the sampling chamber to obtain the background current, and determine the low threshold current, high threshold current and tail threshold current, and set the volume confirmation rules.

[0077] The sample preparation module is used to determine the volume of target acid to be added and the volume of buffer solution based on the initial concentration of target acid, target acidity and preset target volume, and to generate the sample preparation solution.

[0078] The column pretreatment module is used to switch the flow path to the separation column inlet and sequentially deliver low acid washing solution, buffer solution and preset equilibration solution according to a preset column bed volume multiple to generate a separation column that has completed pretreatment and equilibration.

[0079] The sample loading determination module is used to deliver the sample loading solution at a preset fixed sample loading flow rate, obtain the output current of the ionization chamber, and compare it with the low threshold current and the high threshold current. Combined with the volume confirmation rule, it determines the no-product state, the product preparation state, or the forced product state.

[0080] The column washing linkage module is used to form a column washing gradient according to a preset column bed volume multiple after sample loading. When the output current of the ionization chamber is higher than the high threshold current and meets the volume confirmation rule, the collection valve is switched to the product bottle and the organic elution solvent is switched.

[0081] The elution and collection module is used to perform elution at a fixed organic elution flow rate according to the elution bag volume, obtain the output current of the ionization chamber and compare it with the low threshold current, high threshold current and tail threshold current, control the switching of the collection valve in combination with the volume confirmation rules, and determine the actual product volume.

[0082] It should be noted that the range and threshold size are set for ease of comparison. The size of the threshold depends on the amount of sample data and the number of bases set by those skilled in the art for each set of sample data, as long as it does not affect the ratio between the parameter and the quantized value.

[0083] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of the present embodiments, all of which are within the protection scope of the present embodiments.

Claims

1. An automated reconstitution and delivery control method for At-211 separation, characterized by, Includes the following steps: Step 1: Obtain the column bed volume of the separation column, set the minimum action volume particle size, and determine the pump running time based on the preset target volume; Step 2: Fix the target acid, low-acid washing solution, buffer solution, organic elution solvent, and the inlet of the multi-inlet selector valve one-to-one. Receive the background current by delivering the buffer solution through the sampling chamber, and determine the low threshold current, high threshold current, and tail threshold current. Set volume validation rules, including: Step 21: Obtain the inlet number of the multi-inlet selection valve and the list of preset reagent names, and fix the target acid, low acid washing solution, buffer solution, organic elution solvent and the inlet of the multi-inlet selection valve one by one to obtain the inlet mapping; Step 22: Switch to the corresponding inlet of the buffer according to the inlet mapping and deliver the buffer through the sampling chamber to obtain the ionization chamber output current sampling sequence during the buffer delivery, and determine the minimum sampling value in the ionization chamber output current sampling sequence as the background current. Step 23: Obtain the preset threshold generation rule and volume confirmation rule. Add the background current to the preset low threshold current increment to obtain the low threshold current. Add the background current to the preset high threshold current increment to obtain the high threshold current. Add the background current to the preset tail threshold current increment to obtain the tail threshold current. Take the cumulative transport volume reaching the preset confirmation volume as the effective condition for the volume confirmation rule. Step 3: Based on the initial concentration of the target acid, the target acidity, and the preset target volume, determine the volume of the target acid to be added and the volume of the buffer solution to generate the loading solution, including: Step 31: Obtain the initial concentration of the target acid, the target acidity, and the preset target volume. Determine that the initial concentration of the target acid, the target acidity, and the preset target volume have all been obtained and are valid values. Perform a volume granularity consistency check on the preset target volume to confirm that the preset target volume meets the integer multiple constraint of the minimum action volume granularity. Obtain the preset target volume that has passed the check. Step 32: Multiply the target acidity by the preset target volume that has passed the verification to obtain the first result; divide the first result by the initial concentration of the target acid to obtain the target acid addition volume; divide the target acid addition volume by the minimum action volume particle size and take the integer as the normalization factor; multiply the normalization factor by the minimum action volume particle size to obtain the normalized target acid addition volume. Step 33: Subtract the normalized target acid addition volume from the verified preset target volume to obtain the buffer volume. Divide the buffer volume by the minimum action volume particle size and take the integer as the normalization factor. Multiply the normalization factor by the minimum action volume particle size to obtain the normalized buffer volume. Step 34: Switch the inlet mapping to the inlet corresponding to the target acid and deliver the target acid according to the corrected volume; switch the inlet mapping to the inlet corresponding to the buffer solution and deliver the buffer according to the corrected volume, deliver the target acid and buffer to the same target container and mix them to obtain the loading solution; Step 4: Switch the flow path to the column inlet and sequentially deliver low acid washing solution, buffer solution and preset equilibration solution according to the preset column bed volume multiple to generate a pre-treated and equilibrated column. Step 5: Deliver the sample solution at a preset fixed sample flow rate, obtain the output current of the ionization chamber, and compare it with the low threshold current and the high threshold current. Combine the volume confirmation rules to determine the no-product state, product-ready state, or forced product state. Step 6: After the sample loading is completed, a column washing gradient is formed according to the preset column bed volume multiple. When the output current of the ionization chamber is higher than the high threshold current and the volume confirmation rule is met, the collection valve is switched to the product bottle and the organic elution solvent is switched. Step 7: Perform elution at a fixed organic elution flow rate according to the elution bag volume, obtain the output current of the ionization chamber and compare it with the low threshold current, high threshold current and tail threshold current, control the switching of the collection valve in combination with the volume confirmation rules, and determine the actual product volume.

2. The automated reconstitution and delivery control method for At-211 separation of claim 1, wherein, Obtain the column bed volume of the separation column, set the minimum operating volume particle size, and determine the pump runtime based on the preset target volume, including: Step 11: Obtain the inner diameter of the separation column, the height of the column bed, and the column bed porosity. Take half of the inner diameter of the separation column as the radius and calculate the circular cross-sectional area. Multiply the circular cross-sectional area by the column bed height to obtain the column volume, and multiply the column volume by the column bed porosity to obtain the column bed volume. Step 12: According to the preset minimum action volume particle size generation rule, determine the minimum action volume particle size based on the column bed volume, divide the subsequent liquid preparation volume and delivery volume by the minimum action volume particle size and take the integer as the normalization factor, and multiply the normalization factor by the minimum action volume particle size to obtain the normalized liquid preparation volume and the normalized delivery volume. Step 13: Obtain the preset target volume and preset fixed pump flow rate, calculate the ratio of the preset target volume to the preset fixed pump flow rate, and obtain the pump running time.

3. The automated solution preparation and delivery control method for At-211 separation according to claim 1, characterized in that, Switch the flow path to the column inlet and sequentially deliver low-acid wash buffer, buffer solution, and pre-set equilibration solution in multiples of the preset column bed volume to generate a pre-treated and equilibrated separation column, including: Step 41: Obtain the column bed volume, minimum action volume granularity and preset column bed volume multiple sequence. Multiply each preset column bed volume multiple in the preset column bed volume multiple sequence with the column bed volume to obtain the corresponding preset conveying volume. Perform volume granularity consistency check on each preset conveying volume to confirm that each preset conveying volume meets the integer multiple constraint of the minimum action volume granularity. Step 42: Switch the flow path to the inlet of the separation column and point the outlet of the separation column to the waste liquid. Call the inlet mapping to switch to the corresponding inlets of low acid washing solution, buffer solution and preset equilibrium solution in sequence, and deliver them according to the corresponding preset delivery volume. Step 43: Obtain the completion status of low acid washing column solution delivery, buffer solution delivery, and preset equilibrium solution delivery. Under the condition that the separation column outlet points to the waste liquid, the consistency of the three is judged according to the delivery sequence. When the judgment is passed, a separation column that has completed pretreatment and equilibrium is generated.

4. The automated solution preparation and delivery control method for At-211 separation according to claim 1, characterized in that, The sample solution is delivered at a preset fixed loading flow rate, the output current of the ionization chamber is obtained, and compared with the low threshold current and high threshold current. Based on volume confirmation rules, the state is determined as either product-free, product-ready, or forced product state, including: Step 51: Obtain the preset fixed loading flow rate, loading solution, pre-treated and balanced separation column, low threshold current and high threshold current; deliver the loading solution into the pre-treated and balanced separation column at the preset fixed loading flow rate; obtain the ionization chamber output current sampling sequence; and obtain the loading delivery time. Step 52: Compare each sampled value in the ionization chamber output current sampling sequence with the low threshold current and the high threshold current respectively to obtain the threshold comparison result sequence. Determine the product of the preset fixed sample loading flow rate and the sample loading and delivery time as the cumulative delivery volume. Obtain the volume confirmation rule and the preset confirmation volume. Determine the effective threshold when the cumulative delivery volume reaches the preset confirmation volume. Step 53: When the cumulative delivery volume corresponding to the threshold comparison result sequence reaches the effective threshold, the corresponding threshold comparison result is recorded as the confirmed comparison result sequence, and the no-product state, product preparation state, or forced product state is determined according to the preset state mapping rule. Specifically, when the confirmed comparison result sequence is lower than the low threshold current, the no-product state is determined; when the confirmed comparison result sequence is between the low threshold current and the high threshold current, the product preparation state is determined; and when the confirmed comparison result sequence is higher than the high threshold current, the forced product state is determined.

5. The automated solution preparation and delivery control method for At-211 separation according to claim 1, characterized in that, After sample loading, a column washing gradient is formed according to a preset column bed volume multiple. When the ionization chamber output current is higher than the high threshold current and the volume confirmation rule is met, the collection valve is switched to the product vial and the organic elution solvent is switched, including: Step 61: After the sample loading is completed, obtain the high threshold current, the preset confirmation volume and the cumulative delivery volume, and obtain the ionization chamber output current. Compare the ionization chamber output current with the high threshold current to obtain the high threshold comparison result. Determine the cumulative delivery volume as the volume confirmation result when it reaches the preset confirmation volume. Step 62: During the column washing gradient process, obtain the high threshold comparison result and the volume confirmation result, and determine the high threshold comparison result as the ionization chamber output current being higher than the high threshold current and the volume confirmation result being valid as the linkage switching trigger condition. Step 63: When the linkage switching trigger condition is met, switch the collection valve to the product bottle and call the inlet mapping to switch to the corresponding inlet of the organic elution solvent.

6. The automated solution preparation and delivery control method for At-211 separation according to claim 1, characterized in that, Elution is performed at a fixed organic elution flow rate based on the elution bag volume. The output current of the ionization chamber is obtained and compared with the low threshold current, high threshold current, and tail threshold current. Combined with volume confirmation rules, the collection valve is switched to determine the actual product volume, including: Step 71: Obtain the fixed organic elution flow rate, elution bag volume, low threshold current, high threshold current, tail threshold current, volume confirmation rules and preset confirmation volume; deliver organic elution solvent according to the elution bag volume at the fixed organic elution flow rate and obtain the ionization chamber output current sampling sequence. Step 72: Compare each sampled value in the ionization chamber output current sampling sequence with the low threshold current, high threshold current, and tail threshold current to obtain a threshold comparison result sequence, obtain the elution transport time, determine the product of the fixed organic elution flow rate and the elution transport time as the cumulative transport volume, and determine the volume confirmation result when the cumulative transport volume reaches the preset confirmation volume. Step 73: When the volume confirmation result is valid, the threshold comparison result sequence is recorded as the confirmed comparison result sequence. The collection valve is controlled to switch between the product bottle and the tail liquid or waste liquid according to the confirmed comparison result sequence. The actual product volume is determined based on the cumulative transport volume during the period when the collection valve is pointing to the product bottle.

7. The automated solution preparation and delivery control method for At-211 separation according to claim 6, characterized in that, The actual product volume is determined based on the cumulative conveyed volume during the period when the collection valve is pointing towards the product bottle, including: Step 81: Obtain the current pointing state of the collection valve and the cumulative conveying volume, and record the cumulative conveying volume when the current pointing state of the collection valve is a product bottle, so as to obtain the cumulative conveying volume of the product bottle; Step 82: Obtain the confirmed comparison result sequence. When the current state of the collection valve is the product bottle and the confirmed comparison result sequence is below the tail threshold current, generate the product segment end flag and lock the product segment end state. Step 83: When the product segment ends and the state is locked, disable the switching action of the collection valve switching command that points to the product bottle, and determine the cumulative conveying volume of the product bottle as the actual product volume.

8. An automated liquid preparation and delivery control system for At-211 separation, characterized in that, The automated solution preparation and delivery control method for At-211 separation as described in any one of claims 1-7 includes: The column bed quantitative module is used to obtain the column bed volume of the separation column, set the minimum operating volume particle size, and determine the pump running time based on the preset target volume; The threshold criterion module is used to fix the target acid, low acid washing solution, buffer solution, organic elution solvent and the inlet of the multi-inlet selector valve one by one, deliver the buffer solution through the sampling chamber to obtain the background current, and determine the low threshold current, high threshold current and tail threshold current, and set the volume confirmation rules. The sample preparation module is used to determine the volume of target acid to be added and the volume of buffer solution based on the initial concentration of target acid, target acidity and preset target volume, and to generate the sample preparation solution. The column pretreatment module is used to switch the flow path to the separation column inlet and sequentially deliver low acid washing solution, buffer solution and preset equilibration solution according to a preset column bed volume multiple to generate a separation column that has completed pretreatment and equilibration. The sample loading determination module is used to deliver the sample loading solution at a preset fixed sample loading flow rate, obtain the output current of the ionization chamber, and compare it with the low threshold current and the high threshold current. Combined with the volume confirmation rule, it determines the no-product state, the product preparation state, or the forced product state. The column washing linkage module is used to form a column washing gradient according to a preset column bed volume multiple after sample loading. When the output current of the ionization chamber is higher than the high threshold current and meets the volume confirmation rule, the collection valve is switched to the product bottle and the organic elution solvent is switched. The elution and collection module is used to perform elution at a fixed organic elution flow rate according to the elution bag volume, obtain the output current of the ionization chamber and compare it with the low threshold current, high threshold current and tail threshold current, control the switching of the collection valve in combination with the volume confirmation rules, and determine the actual product volume.

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