WO2023231385A1 - Enrichment detection method and apparatus for trace heavy metal elements in liquid - Google Patents

Abstract

An enrichment detection method and apparatus for trace heavy metal elements in a liquid. The method comprises: providing an original liquid sample and an internal standard solution (5), and making a mixed liquid sample according to the original liquid sample and the internal standard solution (5); extracting, from the mixed liquid sample, a liquid sample to be subjected to detection, and performing enrichment on the liquid sample to be subjected to detection, so as to obtain a target sample (6); and performing fluorescence spectroscopy on the target sample (6) by using a monochromatic focus X-ray fluorescence (XRF) analysis device (3), so as to obtain an element detection result. Measurement is performed by using a monochromatic focus XRF analysis device (3), such that a scattering background is greatly reduced, the required detection precision and detection limit can be achieved by means of a very small amount of liquid to be subjected to detection, and the on-site rapid detection of trace heavy metal elements is realized; moreover, the detection limit of the liquid reaches the μg/L level, and the present application has a wide application range and high application value. The monochromatic focus XRF analysis device (3) comprises a device body (31), an X-ray source (32), a hyperbolic crystal optical device (33), a detector (34) and a processor (35).

Description

Enrichment detection method and device for trace heavy metal elements in liquids

This application requires the priority of the Chinese patent application submitted to the China Patent Office on June 1, 2022, with the application number 202210617981.9 and the invention name "Method and Device for Enrichment Detection of Trace Heavy Metal Elements in Liquids", and all its contents have been approved This reference is incorporated into this application.

Technical field

The invention relates to the technical field of enrichment and detection of heavy metal elements in liquids, and in particular to a method and device for enrichment and detection of trace heavy metal elements in liquids.

Background technique

The content of heavy metal elements in some liquids is usually very low, such as surface water, which is at trace levels. Laboratory methods and on-site testing methods are usually used to detect them. Laboratory methods include atomic absorption spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry. These methods are extremely sensitive and can directly detect heavy metal elements in extremely low concentrations in surface water. However, the sample pretreatment process of this type of method is extremely complex and time-consuming; in addition, the equipment is large in size and weight, making it impossible to conduct rapid on-site testing, and its applicable scope and use environment are limited. Therefore, for the detection of heavy metal elements in liquids such as surface water, on-site detection methods are more practical. On-site detection methods usually use anodic stripping voltammetry, which has high detection sensitivity and fast analysis speed. However, the electrodes need to be replaced regularly, calibration is frequent, the instrument requires a lot of maintenance, and the data is unstable. In addition, this method is an electrochemical analysis method, and the use of toxic chemical reagents and heavy metal electrodes will also cause pollution to the environment. Therefore, there is still a need to seek new breakthroughs in on-site detection of heavy metal elements in liquids.

In recent years, X-ray fluorescence (XRF) analysis technology has gained increasing popularity in the composition detection of solid samples due to its advantages such as simple sample processing, simultaneous measurement of multiple elements, non-destructive detection, fast speed, easy operation and on-site use. The more applications. However, when XRF analysis technology is directly used to measure liquid samples, it will cause a relatively high scattering background. Therefore, the ability of XRF analysis technology to detect the element content in liquid samples is very limited. It can usually only reach the mg/L level, which cannot meet the requirements. Detection requirements for heavy metal elements with low levels of μg/L in liquids. By using total reflection XRF (TXRF) analysis technology, the detection limit of direct detection of liquid samples can reach the μg/L level. This technology can be used for direct detection of heavy metal elements in liquids, but most of this type of equipment is used in laboratories. For scientific research use, there are no commercial instruments for sale, which cannot meet the needs of on-site rapid testing by departments at all levels.

Therefore, in order to seek breakthroughs in on-site detection of heavy metal elements in liquids, how to use XRF analysis technology to achieve rapid on-site detection while making the detection limit of liquids reach the μg/L level has become a technical difficulty at this stage.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is how to use XRF analysis technology to achieve rapid on-site detection while making the detection limit of liquids reach the μg/L level.

In order to solve the above technical problems, the present invention provides an enrichment detection method for trace heavy metal elements in liquid, including:

Provide an original liquid sample and an internal standard solution, and prepare a mixed liquid sample based on the original liquid sample and the internal standard solution;

Extract a liquid sample to be tested from the mixed liquid sample, enrich the liquid sample to be tested, and obtain a target sample;

Monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results.

Preferably, the internal standard solution includes any one of yttrium standard solution and tungsten standard solution.

Preferably, the preparation of a mixed liquid sample based on the original liquid sample and the internal standard solution includes:

Filter the original liquid sample to obtain a filtered liquid sample;

Put the filtered liquid sample into a centrifuge tube;

Add a first preset volume of the internal standard solution to the filtered liquid sample in the centrifuge tube, and mix evenly to obtain the mixed liquid sample.

Preferably, the step of extracting the liquid sample to be tested from the mixed liquid sample includes:

Using a syringe, the liquid sample to be tested is extracted from the mixed liquid sample according to the second preset volume.

Preferably, the step of enriching the liquid sample to be tested to obtain a target sample includes:

Connect an enrichment head to the head of the syringe that draws the liquid sample to be tested, and place the syringe connected with the enrichment head into an automatic enrichment device;

According to the preset enrichment time, the automatic enrichment device is used to automatically enrich the liquid sample to be tested in the syringe to obtain the target sample.

Preferably, the centrifuge tube is specifically a disposable centrifuge tube, and/or the syringe is specifically a disposable syringe, and/or the enrichment head is specifically a disposable enrichment head.

Preferably, after enriching the water sample to be tested to obtain the target sample, the method further includes:

From the syringe, remove the enrichment tip containing the target sample.

Preferably, the monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results, including:

Based on the X-ray fluorescence analysis method, the monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample in the enrichment head to obtain the element detection results.

In addition, the present invention also proposes an enrichment detection device for trace heavy metal elements in liquid, including:

Mixed sample making equipment, used to provide an original liquid sample and an internal standard solution, and make a mixed liquid sample based on the original liquid sample and the internal standard solution;

Enrichment equipment, used to extract a liquid sample to be tested from the mixed liquid sample, enrich the liquid sample to be tested, and obtain a target sample;

Monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results.

Preferably, the monochromatic focused X-ray fluorescence analysis equipment includes:

Equipment body;

The X-ray source is located in the device body;

A hyperbolic crystal optical device is installed in the device body and located on the output optical path of the X-ray source, for receiving the X-rays emitted by the X-ray source and monochromating the X-rays to obtain A monochromatic beam, and using the monochromatic beam to excite the target sample;

A detector, located within the device body, is used to detect the X-ray fluorescence signal generated by the target sample after being excited by the monochromatic beam; and

A processor, located in the device body, is used to receive the X-ray fluorescence signal, and perform fluorescence spectrum analysis on the target sample according to the X-ray fluorescence signal to obtain trace amounts of heavy metal elements in the target sample. Corresponding element detection results.

The technical solution provided by the present invention has the following advantages:

The mixed liquid sample is made from the original liquid sample and the internal standard solution, which facilitates subsequent correction and determination of trace heavy metal elements in the liquid sample to be measured based on the known concentration value of the internal standard solution based on the internal standard method to ensure measurement accuracy. ; By extracting the liquid sample to be measured from the mixed liquid sample and enriching the liquid sample to be measured, the concentration of the element to be measured in the liquid sample to be measured can be increased to achieve the direct detection of low-content heavy metal elements in the μg/L level in the liquid. Requirements: Monochromatic focused X-ray fluorescence analysis equipment can monochromatize and focus complex-colored and divergent X-rays emitted from conventional X-ray tubes by using hyperbolic crystal optics to reduce scattering background, that is, based on monochromatic focused XRF analysis technology , can greatly improve the detection sensitivity of conventional XRF analysis technology, reduce the detection limit, and the detection limit of direct detection of liquid samples can reach the sub-mg/L level; the present invention uses monochromatic focusing XRF analysis equipment to perform enrichment on the target sample. The measurement greatly reduces the scattering background and reaches extremely low element detection limits. A very small amount of the liquid to be measured is required for enrichment to achieve the required detection accuracy and detection limit, realizing the detection of trace heavy metal elements in the liquid. Rapid on-site detection also enables the detection limit of liquids to reach the μg/L level, which has a wider scope of application and high application value.

Instructions with pictures

Figure 1 is a schematic flow chart of a method for enrichment and detection of trace heavy metal elements in liquids according to an embodiment of the present invention;

Figure 2 is a schematic flow chart of preparing a mixed liquid sample according to an embodiment of the present invention;

Figure 3 is a schematic diagram of a model structure for enrichment detection of trace heavy metal elements in liquids according to the embodiment of the present invention;

Figure 4 is a schematic structural diagram of the enrichment head according to the embodiment of the present invention;

Figure 5 is a schematic structural diagram of a monochromatic focused X-ray fluorescence analysis device according to an embodiment of the present invention;

Figure 6 is a schematic structural diagram of a device for enrichment and detection of trace heavy metal elements in liquids according to an embodiment of the present invention.

Explanation of reference symbols:

1. Mixed sample preparation equipment, 2. Enrichment equipment, 3. Monochromatic focused X-ray fluorescence analysis equipment, 4. Filtered liquid sample, 5. Internal standard solution, 6. Target sample, 11. Centrifuge tube, 21. Syringe, 22. Enrichment head, 23. Automatic enrichment device, 24. Enrichment cup holder, 31. Equipment body, 32. X-ray source, 33. Hyperbolic crystal optical device, 34. Detector, 35. Processor, 221. Powder enrichment cup, 222. Powder enrichment cover, 223. Microporous sieve plate, 224. Enriched ion powder, 225. Microporous filter membrane, 226. Membrane collar, 227. Rubber gasket.

Detailed ways

Trace elements refer to any element whose content is less than one part per million (ppm level). Usually, other elements in the earth's crust except for the ten elements O, H, Si, Al, Fe, Ca, Mg, Na, K, and Ti (their total weight abundance accounts for about 99%) are collectively called trace elements or trace elements. quantity elements.

The enrichment detection method and device of trace heavy metal elements in liquids of the present invention can be applied to any liquid containing trace heavy metal elements, such as surface water and groundwater. The following embodiments are applied to the detection of trace heavy metal elements in surface water. The measurement will be explained as an example.

Embodiment 1

As shown in Figure 1, this embodiment provides a method for enrichment and detection of trace heavy metal elements in liquid, including:

S1: Provide an original liquid sample and an internal standard solution, and prepare a mixed liquid sample based on the original liquid sample and the internal standard solution.

Preferably, the internal standard solution includes any one of yttrium standard solution and tungsten standard solution.

Through different internal standard solutions, different enrichment materials can be used to enrich the liquid sample to be tested, and finally targeted analysis and determination of heavy metal elements can be carried out.

Before S1, this embodiment also includes:

Prepare the internal standard solution.

Specifically, in this embodiment, the original liquid sample is a surface water sample.

Before S1, this embodiment also includes:

A third predetermined volume of said original liquid sample is obtained from surface water.

Specifically, in this embodiment, the third preset volume is 20 ml.

Preferably, as shown in Figure 2, in S1, a mixed liquid sample is prepared based on the original liquid sample and the internal standard solution, including:

S11: Filter the original liquid sample to obtain a filtered liquid sample;

S12: Put the filtered liquid sample into a centrifuge tube;

S13: Add a first preset volume of the internal standard solution to the filtered liquid sample in the centrifuge tube, and mix evenly to obtain the mixed liquid sample.

By filtering the original liquid sample, the impurities in the original liquid sample can be filtered out, which can improve the measurement accuracy of trace heavy metal elements to a certain extent. Mixing the filtered liquid sample with the internal standard solution according to the above steps can improve the subsequent measurement. The enrichment effect facilitates the correction and determination of trace heavy metal elements in liquid samples that need to be measured based on the known concentration value of the internal standard solution based on the internal standard method to ensure measurement accuracy.

Specifically, as shown in Figure 3, in this embodiment S13, the first preset volume is 1 ml, and the capacity of the centrifuge tube 11 is 50 ml. When 20 ml of the filtered liquid sample 4 is placed into the 50 ml centrifuge tube 11, After adding 1 ml of the internal standard solution 5 to the filtered liquid sample 4 in the centrifuge tube 11, shake for 3 to 5 times to achieve a mixing effect, and obtain a 21 ml mixed liquid sample.

As shown in Figure 1, in S2, a liquid sample to be tested is extracted from the mixed liquid sample, and the liquid sample to be tested is enriched to obtain a target sample.

Preferably, in S2, extract the liquid sample to be tested from the mixed liquid sample, including:

S21: Use a syringe to extract the liquid sample to be tested from the mixed liquid sample according to the second preset volume.

The second preset volume of the liquid sample to be tested is extracted from the mixed liquid sample through a syringe, which on the one hand enables the mixed liquid sample to be used for multiple on-site tests and on the other hand avoids contamination of the mixed liquid sample.

Specifically, the capacity of the syringe in this embodiment is 30 ml, and the second preset volume is set according to the actual situation.

Preferably, in S2, the liquid sample to be tested is enriched to obtain a target sample, including:

S22: Connect the enrichment head to the head of the syringe that draws the liquid sample to be tested, and place the syringe connected with the enrichment head into the automatic enrichment device.

S23: According to the preset enrichment time, use the automatic enrichment device to automatically enrich the liquid sample to be tested in the syringe to obtain the target sample.

Through the above enrichment steps, it is possible to complete the enrichment process of the liquid sample to be measured with less liquid and shorter enrichment time, achieve the required measurement accuracy and detection limit, and avoid the saturation phenomenon of the enriched material.

Preferably, as shown in Figure 3, the centrifuge tube 11 is a disposable centrifuge tube, and/or the syringe 21 is a disposable syringe, and/or the enrichment head 22 is a disposable syringe. Sexual enrichment head.

The enrichment membranes in existing enrichment devices use imported finished heavy metal ion enrichment membranes, which are relatively expensive. When used on-site, most of the consumables used are reused, and there is a possibility of cross-contamination between samples. , it is difficult to guarantee the reproducibility and accuracy of the measurement results; and before each new enrichment operation, some pipelines and other consumables must be cleaned. On-site operations are cumbersome and time-consuming, and the cleaning is likely to be incomplete and the effect is difficult to achieve. ensure. In this embodiment, the above-mentioned disposable consumables can be used once on site, which can avoid the introduction of contamination to the liquid sample to be tested to the greatest extent, achieve good reproducibility, and the results are accurate and reliable; there is basically no need for cleaning and maintenance on site. Disposable consumables can be cleaned at leisure for reuse.

Specifically, in S22, the connection between the enrichment head 22 and the head of the syringe 21 is in the form of a Luer connector.

Specifically, in S22, the enrichment head 22 adopts a disposable sealed package. As shown in Figure 4, the enrichment head 22 includes a powder enrichment cup 221, a powder enrichment cover 222, a microporous sieve plate 223, and enrichment ions. Powder 224, microporous filter membrane 225, membrane collar 226 and rubber gasket 227; the powder enrichment cup 221 is provided with a through channel, a bayonet is provided on the channel, and a microporous screen plate 223 is provided on the bayonet. The sieve plate 223 matches the powder enrichment cup 221, and the enriched ion powder 224 is compacted in the powder enrichment cover 222. The powder enrichment cover 222 is connected to the powder enrichment cup 51 in a threaded manner. The specific structure of the enrichment head 22 in this embodiment is an existing technology, and other unexplained details will not be described again here.

In the existing enrichment technology, imported finished heavy metal ion enrichment membranes are used. In this embodiment, ionic resin powder is used as the enrichment material. Compared with the enrichment membrane, the single enrichment cost is low. The solid-phase extraction method is also simpler and faster than other pre-enrichment methods.

Among them, the ion-enriched powder 224 includes cation-enriched resin powder and anion-enriched resin powder. For the cation-enriched resin powder, the internal standard solution added in S1 is a yttrium (Y) standard solution with a concentration of 2 mg/L; Anion-enriched resin powder, the internal standard solution added in S1 is tungsten (W) standard solution, with a concentration of 1 mg/L. In the traditional enrichment technology using enrichment membranes, due to differences in performance between enrichment membranes and differences in the pH value of the liquid used for enrichment, these factors will have an impact on the enrichment process. will have a significant impact on the final measurement results. In this embodiment, targeted internal standard solutions are added to different enriched ion resin powders, and the liquid sample to be tested is obtained after mixing and extracting with a syringe. The internal standard solution undergoes pre-enrichment together with the liquid that needs to be measured. During the process, the heavy metal elements in the liquid are adsorbed by the ion-enriched resin powder to form a viscous target sample. During the enrichment process, the difference in the amount and efficiency of the enriched ion resin powder has the same effect on the elements in the liquid that needs to be measured and the elements in the internal standard solution. The pH value of the elements in the liquid and the internal standard solution are the same. The same is true for the influence of elements in the standard solution. In the final spectrum obtained by fluorescence spectrum analysis, the net count values of the elements in the liquid that need to be measured and the elements in the internal standard solution are uniformly high or low, so in the quantitative In the algorithm, the final measurement result can be corrected by using the known concentration value of the internal standard solution to minimize the possible effects caused by factors such as the amount of enriched ion resin powder and the pH value of the liquid to be measured, ensuring measurement accuracy.

Specifically, as shown in Figure 3, in this embodiment, the syringe 21 connected to the enrichment head 22 is placed into the automatic enrichment device 23, the enrichment speed remains at the default setting, and the "Start" button on the automatic enrichment device 23 is clicked. , starts the automatic enrichment process. The preset enrichment time can be set according to the actual situation. In this embodiment, it is set to 3 minutes, that is, the entire automatic enrichment process lasts for 3 minutes. After the automatic enrichment is completed, the target sample is obtained. The automatic enrichment device 23 in this embodiment is an enrichment device in the prior art, and the specific details will not be described again here.

Preferably, after S23, it also includes:

From the syringe, remove the enrichment tip containing the target sample.

By removing the enrichment head, it is convenient to send the target sample into the monochromatic focused X-ray fluorescence analysis equipment for fluorescence spectrum analysis to achieve the determination of heavy metal elements in the target sample.

Specifically, in this embodiment, as shown in Figure 3, after removing the enrichment head 22 from the syringe 21, unscrew the powder enrichment cover 222 above the enrichment head 22 to expose the powder enrichment cup 221, and then The powder enrichment cup 221 is installed on the enrichment cup holder 24 that matches the powder enrichment cup 221 .

As shown in Figure 1, S3, use monochromatic focused X-ray fluorescence analysis equipment to perform fluorescence spectrum analysis on the target sample to obtain element detection results.

Preferably, S3 includes:

Based on the X-ray fluorescence analysis method, the monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample in the enrichment head to obtain the element detection results.

Due to the low sensitivity and high detection limit of conventional XRF analysis equipment, in order to meet the detection limit requirements of heavy metal elements in liquids such as surface water, a large amount of liquid must be used for pre-enrichment, which takes a long time and can easily cause enrichment. Diaphragm saturation phenomenon. This embodiment uses monochromatic focused X-ray fluorescence analysis equipment to measure the enriched sample, which greatly reduces the scattering background and reaches extremely low element detection limits. A very small amount of liquid to be measured is required for enrichment. It achieves the required detection accuracy and detection limit, effectively avoids the saturation phenomenon of enriched materials, and greatly shortens the enrichment time.

Specifically, as shown in Figure 5, the monochromatic focused X-ray fluorescence analysis equipment 3 of this embodiment includes: an equipment body 31; an X-ray source 32, located in the equipment body 31; and a hyperbolic crystal optical device 33, located in The device body 31 is located on the output optical path of the X-ray source, and is used for receiving the X-rays emitted by the X-ray source, monochromating the X-rays to obtain a monochromatic light beam, and utilizing the X-rays. The monochromatic beam excites the target sample 6 .

The detector 34 is located in the device body 31 and is used to detect the X-ray fluorescence signal generated by the target sample 6 after being excited by the monochromatic beam; and the processor 35 is located in the device body 31 , used to receive the X-ray fluorescence signal, and perform fluorescence spectrum analysis on the target sample 6 according to the X-ray fluorescence signal to obtain the element detection results corresponding to the trace heavy metal elements in the target sample 6 .

The monochromatic focused X-ray fluorescence analysis equipment with the above structure uses high-efficiency hyperbolic crystal optical devices to monochromatize and focus the polychromatic and divergent X-rays emitted by the X-ray source. On the one hand, the monochromatization greatly reduces the scattering. background, which improves the sensitivity. On the other hand, due to focusing, the useful X-ray intensity in the sample area is greatly improved and the signal intensity is improved; the monochromatic focused X-ray is set to irradiate the surface of the target sample at a very small angle, so that the sample and The distance between detectors can be made very small, which significantly increases the collection solid angle of the detector, further improves the system sensitivity and reduces the detection limit.

Specifically, the monochromatic focused X-ray fluorescence analysis equipment 3 is also provided with a sample chamber and a safety door. The powder enrichment cup 221 of this embodiment is placed in a sideways sampling manner using the enrichment cup holder 24 on it. Enter the sample room of the monochromatic focused X-ray fluorescence analysis equipment 3, close the safety door, and select the corresponding measurement curve for analysis and testing to obtain the content information of heavy metal elements in surface water. For cation-enriched resin powder, select the cation enrichment curve for measurement. The cation enrichment curve is the analysis curve after calibration with standard samples before leaving the factory. The standard samples used are composed of GSB04-1767-2004 multi-element standard solution and pure water. The configuration is obtained, and the gradient concentrations are 0 μg/L, 10 μg/L, 20 μg/L, 50 μg/L and 100 μg/L; for the anion enrichment resin powder, select the anion enrichment curve for measurement, and the anion enrichment curve has also passed the standard. Analysis curve after sample calibration. The standard samples used are prepared from single element standard solutions such as hexavalent chromium, arsenic, and selenium and pure water. The gradient concentrations are 0 μg/L, 10 μg/L, 20 μg/L, 50 μg/L, and 100μg/L.

Each component of the above-mentioned monochromatic focused X-ray fluorescence analysis equipment 3 is an existing technology, and the specific details will not be described again here.

The heavy metal elements in surface water were measured using the method in this example, and the results are shown in Table 1. It can be seen from Table 1 that the detection limit of heavy metal elements in surface water measured using the method in this example is far lower than the standard detection limit restricted by surface water, which greatly reduces the detection limit.

Table 1 Comparative results of determination of heavy metal elements in surface water

Based on the complete enrichment detection method of trace heavy metal elements in liquid in this embodiment, the following beneficial effects can be achieved:

(1) The enrichment head uses enriched ion resin powder, which greatly reduces the cost compared with imported enrichment membranes. After the imported enrichment membrane is cut into the required size by a special die, the cost for a single enrichment is about 20 yuan, while using enriched ion resin powder, the cost of a single enrichment is less than 2 yuan.

(2) Due to differences in the amount and efficiency of the enrichment ion resin powder filled in the enrichment heads of different enrichment materials, in addition, factors such as the pH value of the liquid sample to be tested may also affect the enrichment process; therefore In this embodiment, an internal standard solution is added to the original liquid sample, and after mixing and extraction, the liquid sample to be measured is obtained for the enrichment process. The internal standard solution is adsorbed by the ionic resin together with the heavy metal elements in the liquid to be measured. During the enrichment process, the difference in the amount and efficiency of the enriched ion resin powder has the same effect on the elements in the liquid that needs to be measured and the elements in the internal standard solution. The pH value has the same effect on the elements in the liquid that needs to be measured and the internal standard solution. The same is true for the influence of elements in the solution. In the final fluorescence spectrum, the net count values of the elements in the liquid to be measured and the elements in the internal standard solution are uniformly high or low. Therefore, in the quantitative algorithm, the net count value of the internal standard solution can be used. The known concentration value corrects the final measurement result, minimizing the impact of differences in ion-enriched resin powder and pH value of the liquid to be measured, ensuring measurement accuracy.

(3) During the on-site detection process, the automatic enrichment device itself does not come into contact with the liquid sample to be tested, and there is no cross-contamination phenomenon, ensuring the accuracy of each enrichment and measurement.

(4) During the on-site detection process, the consumables and containers (such as syringes, enrichment heads, etc.) used are single-use, and no cleaning operations are required on site, which saves the enrichment operation steps and time, and there is no need to worry There are residual phenomena. In addition, disposable consumables after use can be collected in special storage bags. After returning to the laboratory, they can be cleaned uniformly using a special process to ensure the cleaning effect and facilitate reuse.

(5) In the monochromatic focusing X-ray fluorescence analysis equipment used, high-efficiency hyperbolic crystal optical devices are used to monochromatize and focus the polychromatic and divergent X-rays emitted by the X-ray source. On the one hand, due to the monochromatic This greatly reduces the scattering background and improves the sensitivity. On the other hand, due to focusing, the useful X-ray intensity in the sample area is greatly increased and the signal intensity is improved; the monochromatic focused X-ray is set to illuminate the target sample at a very small angle. The surface allows the distance between the sample and the detector to be very small, significantly increasing the collection solid angle of the detector, further improving the system sensitivity and lowering the detection limit.

Embodiment 2

As shown in Figure 6, this embodiment provides an enrichment detection device for trace heavy metal elements in liquid, including:

Mixed sample preparation equipment 1 is used to provide an original liquid sample and an internal standard solution, and prepare a mixed liquid sample based on the original liquid sample and the internal standard solution.

The enrichment device 2 is used to extract a liquid sample to be tested from the mixed liquid sample, and enrich the liquid sample to be tested to obtain a target sample.

Monochromatic focused X-ray fluorescence analysis equipment 3 is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results.

The enrichment detection device of this embodiment uses monochromatic focusing XRF analysis equipment to measure the target sample after enrichment, which greatly reduces the scattering background and reaches extremely low element detection limits, requiring a very small amount of liquid to be measured. Enrichment can achieve the required detection accuracy and detection limit, and realize on-site rapid detection of trace heavy metal elements in liquids. At the same time, the detection limit of liquids can reach the μg/L level, which has a wider scope of application and application value. high.

Specifically, as shown in Figure 3, the mixed sample preparation equipment 1 in this embodiment specifically includes a centrifuge tube 11; as shown in Figure 3, the enrichment equipment 2 includes a syringe 21, an enrichment head 22, an automatic enrichment device 23 and an enrichment device. Cup holder 24; as shown in Figure 5, the monochromatic focused X-ray fluorescence analysis equipment 3 includes an equipment body 31, an X-ray source 32, a hyperbolic crystal optical device 33, a detector 34 and a processor 35.

Specifically, the centrifuge tube 11 is specifically a disposable centrifuge tube, and/or the syringe 21 is specifically a disposable syringe, and/or the enrichment head 22 is specifically a disposable enrichment head.

Specifically, in this embodiment, as shown in Figure 4, the enrichment head 22 includes a powder enrichment cup 221, a powder enrichment cover 222, a microporous screen plate 223, an enriched ion powder 224, a microporous filter membrane 225, a Collar 226 and rubber gasket 227; the powder enrichment cup 221 is provided with a through channel, and a bayonet is provided on the channel. A microporous screen plate 223 is provided on the bayonet, and the microporous screen plate 223 matches the powder enrichment cup 221. , the enriched ion powder 224 is compacted in the powder enrichment cover 222, and the powder enrichment cover 222 is connected to the powder enrichment cup 51 in a threaded connection.

For unfinished details in this embodiment, please refer to the specific description of Embodiment 1 and Figures 1 to 5, and will not be described again here.

Claims (10)

1. The enrichment detection method of trace heavy metal elements in liquid is characterized by including:

   Provide an original liquid sample and an internal standard solution, and prepare a mixed liquid sample based on the original liquid sample and the internal standard solution;

   Extract a liquid sample to be tested from the mixed liquid sample, enrich the liquid sample to be tested, and obtain a target sample;

   Monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results.
2. The method for enrichment and detection of trace heavy metal elements in liquid according to claim 1, wherein the internal standard solution includes any one of an yttrium standard solution and a tungsten standard solution.
3. The method for enrichment detection of trace heavy metal elements in liquid according to claim 1 or 2, characterized in that preparing a mixed liquid sample based on the original liquid sample and the internal standard solution includes:

   Filter the original liquid sample to obtain a filtered liquid sample;

   Put the filtered liquid sample into a centrifuge tube;

   Add a first preset volume of the internal standard solution to the filtered liquid sample in the centrifuge tube, and mix evenly to obtain the mixed liquid sample.
4. The enrichment detection method of trace heavy metal elements in liquid according to claim 3, characterized in that, extracting the liquid sample to be measured from the mixed liquid sample includes:

   Using a syringe, the liquid sample to be tested is extracted from the mixed liquid sample according to the second preset volume.
5. The method for enrichment and detection of trace heavy metal elements in liquid according to claim 4, wherein the step of enriching the liquid sample to be tested to obtain a target sample includes:

   Connect an enrichment head to the head of the syringe that draws the liquid sample to be tested, and place the syringe connected with the enrichment head into an automatic enrichment device;

   According to the preset enrichment time, the automatic enrichment device is used to automatically enrich the liquid sample to be tested in the syringe to obtain the target sample.
6. The method for enrichment and detection of trace heavy metal elements in liquid according to claim 5, wherein the centrifuge tube is a disposable centrifuge tube, and/or the syringe is a disposable syringe, and /Or, the enrichment head is specifically a disposable enrichment head.
7. The enrichment detection method of trace heavy metal elements in liquid according to claim 5, characterized in that, after enriching the water sample to be tested and obtaining the target sample, it also includes:

   From the syringe, remove the enrichment tip containing the target sample.
8. The method for enrichment and detection of trace heavy metal elements in liquids according to claim 7, characterized in that the use of monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results, include:

   Based on the X-ray fluorescence analysis method, the monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample in the enrichment head to obtain the element detection results.
9. The enrichment detection device for trace heavy metal elements in liquid is characterized by including:

   Mixed sample production equipment, used to provide an original liquid sample and an internal standard solution, and prepare a mixed liquid sample based on the original liquid sample and the internal standard solution;

   Enrichment equipment, used to extract a liquid sample to be tested from the mixed liquid sample, enrich the liquid sample to be tested, and obtain a target sample;

   Monochromatic focused X-ray fluorescence analysis equipment is used to perform fluorescence spectrum analysis on the target sample to obtain element detection results.
10. The enrichment detection device for trace heavy metal elements in liquid according to claim 9, characterized in that the monochromatic focused X-ray fluorescence analysis equipment includes:

    Equipment body;

    The X-ray source is located within the device body;

    A hyperbolic crystal optical device is installed in the device body and located on the output optical path of the X-ray source, for receiving the X-rays emitted by the X-ray source and monochromating the X-rays to obtain A monochromatic beam, and using the monochromatic beam to excite the target sample;

    A detector, located within the device body, is used to detect the X-ray fluorescence signal generated by the target sample after being excited by the monochromatic beam; and

    A processor, located in the device body, is used to receive the X-ray fluorescence signal, and perform fluorescence spectrum analysis on the target sample according to the X-ray fluorescence signal to obtain trace amounts of heavy metal elements in the target sample. Corresponding element detection results.

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