Device and method for preparing aldehyde ketone compound absorption liquid

Abstract

The present application relates to a device for preparing an aldehyde ketone compound absorption liquid, comprising: a first container for accommodating an acid solution; the powder column is used for containing DNPH powder and comprises at least two short columns which are detachably connected; the second container is used for containing absorption liquid; the first pipeline is connected with the first container and the powder column, is provided with a first liquid conveying unit and is used for conveying the acid solution in the first container into the powder column; the second pipeline is connected with the powder column and the second container. The invention further provides a method for preparing the aldehyde ketone compound absorption liquid. According to the device and the method provided by the invention, the labor cost can be saved to a great extent, and the preparation efficiency is improved; a specially-made DNPH powder column is adopted, so that DNPH powder is not prone to agglomeration, and the low-blank DNPH high-load aldehyde ketone compound absorption liquid can be prepared. And reagent raw materials are isolated from a human body and are healthy and friendly to the human body.

Description

Technical Field

[0001] This invention relates to the field of gas monitoring, and particularly to an apparatus and method for preparing an aldehyde and ketone compound absorbent. Background Technology

[0002] This invention relates to the field of gas monitoring; specifically, it relates to an apparatus and method for preparing absorbent solutions for aldehydes and ketones. Currently, DNPH absorbent solutions for aldehydes and ketones are mostly prepared artificially using multiple extractions with organic solvents such as dichloromethane and n-hexane (derived from the US EPA standard method "METHOD FOR THE DETERMINATION OF ALDEHYDES AND KETONES IN AMBIENT AIR USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC)" (TO-5) and the Chinese standard "Determination of Aldehydes and Ketones in Ambient Air - Solution Absorption-High Performance Liquid Chromatography" (HJ1154-2020)). For example: Weigh 4.0 g of DNPH powder into a brown reagent bottle, add 180 ml of hydrochloric acid, then add 820 ml of water, and sonicate for 30 min. A saturated solution is formed and filtered. Transfer the filtered saturated DNPH solution to a 2L separatory funnel, add 60ml of dichloromethane, extract for 3 minutes, let stand, and discard the lower organic phase after separation. Repeat the above operation for one more extraction. Finally, extract with 60ml of n-hexane. After the organic phase separates from the DNPH solution, transfer the lower DNPH solution to a brown reagent bottle that has been rinsed with acetonitrile and dried. Seal the bottle and store it in a desiccator containing activated carbon.

[0003] However, this preparation method currently has many problems, such as: cumbersome operation, and due to its short shelf life (to be used within 48 hours), it needs to be prepared in small batches multiple times, which is extremely labor-intensive; the preparation process requires the use of a large amount of organic reagents, which is not friendly to human health; the prepared absorbent has a high background, which is not conducive to low-concentration monitoring. In addition, DNPH powder particles are usually very fine, easily agglomerate and are not easy to disperse and dissolve in solution, thus affecting the DNPH content loaded in the absorbent, and consequently affecting the monitoring results (especially in the case of high sample concentrations). Summary of the Invention

[0004] To address the aforementioned problems in the prior art, embodiments of this application provide an apparatus and method for preparing aldehyde and ketone compound absorbents, which can achieve high efficiency and automation, are human health-friendly, and yield absorbents with low blank levels.

[0005] One embodiment of this application provides an apparatus for preparing an aldehyde-ketone compound absorbent liquid, the apparatus comprising: a first container for containing an acid solution; a powder column for containing DNPH powder, including at least two detachably connected short columns; a second container for containing the absorbent liquid; a first pipeline connecting the first container and the powder column, and provided with a first liquid delivery unit for delivering the acid solution in the first container to the powder column; and a second pipeline connecting the powder column and the second container.

[0006] Furthermore, the device further includes: a third container for containing the extract; a fourth container for containing the purified absorbent; a third pipeline connecting the third container and the second container, and equipped with a second liquid delivery unit for delivering the extract in the third container to the second container; and a fourth pipeline connecting the second container and the fourth container, and equipped with a third liquid delivery unit for delivering the purified absorbent in the second container to the fourth container.

[0007] Furthermore, the device also includes: a gas source and flow control module for providing purge gas for bubbling and mixing; and a switching valve disposed on a second pipeline, wherein the switching valve selectively connects the gas source and flow control module or the powder column to the flow path.

[0008] Furthermore, the device also includes: a fifth container for containing waste liquid; and a fourth liquid conveying unit, connecting the second container and the fifth container, for conveying the waste liquid in the second container to the fifth container.

[0009] Furthermore, the device also includes a first gas purification device, which is disposed on the second container.

[0010] Furthermore, the device also includes a second gas purification device, which is disposed on the fourth container.

[0011] Furthermore, the connecting surface of the short column is provided with a sieve plate.

[0012] Another embodiment of this application provides a method for preparing an aldehyde-ketone compound absorbent, using the apparatus described in any one of the above claims to prepare the aldehyde-ketone compound absorbent, the method comprising: Step S1: The first liquid delivery unit draws a predetermined amount of acid solution from the first container and delivers it to the second container through the powder column; Step S2: The second liquid delivery unit draws a predetermined amount of extract from the third container and delivers it into the second container; Step S3: The gas source and flow control module are connected to the flow path to deliver a predetermined amount of purge gas to the second container for bubbling and extraction for the first predetermined time; Step S4: The third liquid delivery unit starts working for the second predetermined time and delivers the purified DNPH absorbent to the fourth container.

[0013] Furthermore, after step S4, the process also includes cleaning and drying the flow path.

[0014] Furthermore, the cleaning and drying steps include: Step S5: The second liquid delivery unit draws a predetermined amount of extract from the third container and delivers it to the second container; Step S6: The air source and flow control module delivers a predetermined amount of purge air to the second container for bubble cleaning for a third predetermined time; Step S7: The fourth liquid delivery unit operates for a fourth predetermined time to deliver the waste liquid in the second container to the fifth container.

[0015] The apparatus and method provided in this application can achieve at least one of the following beneficial effects: The apparatus and method provided in this application can greatly save labor costs and improve preparation efficiency; A specially designed DNPH powder column is used to prevent DNPH powder from agglomerating, enabling the preparation of aldehyde and ketone compound absorbent solutions with low blank DNPH and high loading. The process is automated, and the reagents and raw materials are isolated from the human body, ensuring human health. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a powder column according to one embodiment of the present invention; Figure 2 This is a schematic diagram of a powder column according to another embodiment of this application; Figure 3 This is a schematic diagram of an apparatus for preparing an absorbent solution of aldehyde and ketone compounds according to another embodiment of this application.

[0017] Explanation of reference numerals in the attached figures: 10-First container; S1-Powder container; S10-Powder column; S11-First column; S12-Second column; S13-Third column; S14-Fourth column; S15-Fifth column; S01-Sieve plate; 20-Second container; 30-Third container; 40-Fourth container; 50-Fifth container; L1-First pipeline; L2-Second pipeline; L21-Second branch line; L3-Third pipeline; L4-Fourth pipeline; L41-Fourth branch line; L42-Fourth branch line; 11-First liquid conveying unit; 12-Second liquid conveying unit; 13-Third liquid conveying unit; 14-Fourth liquid conveying unit; 101-Switching valve; 102-Gas source; 103-First gas purification device; 104-Second gas purification device; 105-Solenoid valve Detailed Implementation The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. In the description of the present invention, it should be noted that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present application.

[0018] The following is in conjunction with the appendix Figures 1 to 3 This application describes the apparatus and method for preparing aldehyde and ketone compound absorbent solutions according to embodiments of the present application.

[0019] like Figure 3 As shown in the figure, one embodiment of this application provides an apparatus 1 for preparing an aldehyde-ketone compound absorbent liquid. The apparatus 1 may include: a first container 10 for containing an acid solution; a powder column S10 for containing DNPH powder, including at least two detachably connected short columns; a second container 20 for containing the absorbent liquid; a first pipeline L1 connecting the first container 10 and the powder column S10, and provided with a first liquid delivery unit 11 for delivering the acid solution in the first container 10 to the powder column S10; and a second pipeline L2 connecting the powder column S10 and the second container 20.

[0020] Preferably, the acid solution contained in the first container 10 can be sulfuric acid, phosphoric acid, etc. The first liquid delivery unit 11 is used to deliver the solution in the first container 10. Specifically, the first liquid delivery unit 11 can be a syringe pump, plunger pump, etc. The first liquid delivery unit 11 can deliver the solution in the first container through the powder column S10 into the second container 20, which contains a saturated DNPH absorbent. Because DNPH powder is prone to agglomeration, leading to unsaturated solution, the powder column S10 in this embodiment is a specially made DNPH powder column. Specifically, the powder column S10 is composed of multiple short columns filled with DNPH powder connected in series, enabling the preparation of a saturated DNPH absorbent.

[0021] For example, Figure 1 The image only shows the case of four small pillars connected in series. Figure 1In the powder column S10, there are four short columns: a first short column S11, a second short column S12, a third short column S13, and a fourth short column S14. For example, each short column is connected by a thread and can be combined and connected in series at will. When replacing, the bottom short column is disassembled according to the actual use, and a new short column is installed on the top. The corresponding connecting surface of each short column is provided with a sieve plate S01. The aperture size of the sieve plate S01 is smaller than the particle size of the DNPH powder. This prevents the DNPH powder from passing through the sieve plate S01, but the sieve plate S01 can be used by liquid. That is to say, the powder in different short columns is isolated from each other. When the first liquid conveying unit 11 conveys the acid solution through the powder column S10, the acid solution can enter the first short column S11 and react with the DNPH powder in the first short column S11 to form a saturated DNPH absorbent liquid. The absorbent liquid passes through the mesh in the sieve plate S01 and sequentially through the second short column S12, the third short column S13, and the fourth short column S14 into the second container 20. After a saturated DNPH absorbent is formed in the first short column S11, it will not react further with the DNPH powder in other short columns, thus avoiding agglomeration. When the remaining DNPH powder in the first short column S11 is insufficient to form a saturated absorbent, the absorbent enters the second short column S12 to further react with the powder until a saturated solution is formed. When the powder in the first short column S11 is used up, a new short column S15 can be installed above the fourth short column S14. The connection between the two short columns is threaded, making operation convenient. Each short column has a sieve plate S01 at its mating surface, shown in the figure only as an example.

[0022] In other embodiments, such as Figure 2As shown, a powder column S10 is connected to the flow path. One side of the powder column S10 is connected to the first container 10 via a first pipe L1, and the other side of the powder column S10 is connected to the second container 20 via a second pipe L2. The powder column S10 is also connected to another powder container S1, which is filled with DNPH powder. The powder container S1 and the powder column S10 are connected by a pipe, and a solenoid valve 105 is installed on this connecting pipe. In this embodiment, a weight sensor is installed on the powder column S10 to accurately and in real time provide feedback on the weight of the powder column S10. In this embodiment, the powder container S1 is positioned above and adjacent to the powder column S10. The wall of the powder container S1 near the outlet is rounded, and the diameter of the powder container S1 narrows at the outlet, so that the DNPH powder in the powder container S1 can be concentrated at the outlet of the powder container S1 by gravity. Preferably, the device 1 includes a control module. When an absorbent needs to be prepared, the required weight of DNPH can be calculated based on the volume of the saturated absorbent to be prepared. The control module controls the solenoid valve 105 to open, allowing a specified weight of DNPH powder to enter the powder column S10. The weight sensor of the powder column S10 can provide real-time feedback on the weight of the powder column until the specified weight of DNPH powder in the powder column S10 is reached, at which point the solenoid valve closes. The first liquid delivery unit 11 on the first pipeline L1 operates, delivering the acid solution in the first container 10 through the powder column S10 into the second container 20. In this embodiment, by setting the powder container S1, the amount of DNPH powder in each reaction can be quantitatively controlled, thus fully forming a saturated absorbent.

[0023] Further reference Figure 3 As shown, the apparatus 1 of this application may further include: a third container 30 for containing the extract; a fourth container 40 for containing the purified DNPH saturated absorbent; a third pipeline L3 connecting the third container 30 and the second container 20, and equipped with a second liquid delivery unit 12 for delivering the extract in the third container 30 to the second container 20; and a fourth pipeline L4 connecting the second container 20 and the fourth container 40, and equipped with a third liquid delivery unit 13 for delivering the purified absorbent in the second container 20 to the fourth container 40. The extract contained in the third container 30 may be chloroform, carbon tetrachloride, etc. The second container 20 serves as an extraction bottle for extracting and purifying the solution. The fourth container 40 is used to contain the purified DNPH absorbent.

[0024] In detail, the fourth pipeline L4 includes a fourth branch L41, which connects the second container 20 and the fourth container 40, and is equipped with a third liquid delivery unit 13. The fourth pipeline L4 also includes a fourth second branch L42, which connects the second container 20 and the fifth container 50, and is equipped with a fourth liquid delivery unit 14 for delivering the purified waste liquid from the second container 20 to the fifth container 50. It is understood that the fourth branch L41 and the fourth second branch L42 are connected in parallel. The fifth container 50 is used to contain the waste liquid. The second liquid delivery unit 12 is used to deliver the solution from the third container 30; the second liquid delivery unit 12 can be a syringe pump, plunger pump, etc. The third liquid delivery unit 13 is used to deliver the purified DNPH saturated absorbent in the second container 20 to the fourth container 40. The liquid delivery unit can be a peristaltic pump, a diaphragm pump, etc. The fourth liquid delivery unit 14 is used to deliver the waste liquid in the second container 20 to the fifth container 50. The fourth liquid delivery unit 14 can be a peristaltic pump, a diaphragm pump, etc.

[0025] The device 1 also includes a gas source and flow control module 102, which provides purge gas for bubbling and mixing; and a switching valve 101, which is disposed on the second pipeline L2. The switching valve 101 is connected to a second branch L21. The second branch L21 is connected to the gas source 102. The switching valve 101 selectively connects the gas source and flow control module 102 or the powder column S10 to the flow path. That is, only one of the powder column S10 and the gas source and flow control module 102 can be connected to the second pipeline L2, thereby connecting to the second container 20. The gas source and flow control module 102 can be nitrogen, helium, etc. In a preferred embodiment, the gas source and flow control module 102 can be a combination of nitrogen and a flow controller. The branch L21 is connected to the second pipeline L2 through the switching valve 101. That is, the powder column S10 and the gas source and flow control module 102 are selectively connected to the flow path through the switching valve 101. Device 1 includes a controller (not shown), which receives control signals from a host computer and then adjusts the signal transmission to change the flow rate of gas through the flow sensor, thereby achieving precise control of the gas flow rate.

[0026] Understandably, the operation of the second pipeline L2 and the third pipeline L3 is as follows: The first container 10 contains an acid solution such as sulfuric acid or phosphoric acid. The first liquid delivery unit 11 operates, drawing the acid solution from the container 10 and delivering it to the powder column S10. Then, the switching valve 101 connects the powder column S10 to the second container 20, allowing the saturated absorbent from the powder column S10 to enter the second container 20. The second liquid delivery unit 12 draws the extract from the third container 30 and delivers it to the second container 20. Then, the switching valve 101 operates again, connecting the gas source and the flow control module 102 to the flow path, thereby delivering the purge gas to the second container 20 for bubbling extraction.

[0027] The apparatus 1 also includes a first gas purification device 103 and a second gas purification device 104. The first gas purification device 103 is connected to the second container 20, and the second gas purification device 104 is connected to the fourth container 40. The first gas purification device 103 is used to balance the pressure and prevent flow path contamination. The second gas purification device 104 is used to balance the pressure and prevent the purified DNPH absorbent from being contaminated. For example, the first gas purification device 103 and the second gas purification device 104 can be filters containing activated carbon, etc. This is only an example, and this application does not limit it.

[0028] The apparatus of the embodiments of this application can realize the automated preparation of aldehyde and ketone compound absorption liquid, the reagent raw materials are isolated from the human body and are friendly to human health, and the preparation efficiency is high.

[0029] Another embodiment of this application provides a method for preparing an aldehyde-ketone compound absorbent liquid, using the apparatus described above for preparing an aldehyde-ketone compound absorbent liquid, the method comprising the following steps: Step S1: Switching valve 101 operates to connect powder column S10 to the flow path. First liquid delivery unit 11 draws a predetermined amount of acid solution from first container 10 and sequentially delivers it through the specially designed DNPH powder column S10 to second container 20. The predetermined amount can be changed as needed, and the acid solution can also be changed according to actual requirements. For example, in one embodiment, first container 10 draws 50 ml of acid solution. The acid solution in first container 10 can be sulfuric acid, phosphoric acid, etc. First liquid delivery unit 11 can preferably be a syringe pump, plunger pump, etc.

[0030] Step S2: The second liquid delivery unit 12 draws a predetermined amount of extract from the third container 30 and delivers it into the second container 20; the predetermined amount can be changed as needed, and the extract can also be changed according to actual needs. For example, in one embodiment, the third container 30 draws 20 ml of extract. The extract is chloroform, carbon tetrachloride, etc. The second liquid delivery unit 12 can preferably be a syringe pump, plunger pump, etc.

[0031] Step S3: Switching valve 101 connects the gas source and flow control module 102 to the flow path. The gas source and flow control module 102 then delivers a predetermined amount of purge gas, such as nitrogen, to the second container 20 for bubbling extraction for a first predetermined time. For example, in one embodiment, the gas source and flow control module 102 sets the nitrogen level to 50 sccm and delivers the nitrogen to the second container 20 for bubbling extraction for 60 seconds, completing the first purification extraction operation.

[0032] Multiple extraction operations can be performed as needed; for example, in this embodiment, two extraction operations are performed. After the first extraction is completed, the switching valve 101 is activated, and the second liquid delivery unit 12 draws another 10 ml of the extracted solution from the third container 30 and delivers it to the second container 20. Next, switching valve 101 operates, and the gas source and flow control module 4 sets the nitrogen gas to 50 sccm, delivering the nitrogen gas to the second container 20 for bubble extraction for 60 seconds, performing the second extraction. Step S3 can be repeated 2 to 4 times.

[0033] Step S4: After the purification and extraction operation is completed, the third liquid delivery unit 13 starts working for a second predetermined time to deliver the purified DNPH saturated absorbent to the fourth container 40, thus completing the preparation of the DNPH absorbent. The predetermined time here is preferably 10 seconds. The third liquid delivery unit 11 can preferably be a peristaltic pump or a diaphragm pump.

[0034] In a preferred embodiment, the method for preparing aldehyde and ketone compound absorbent provided in this application further requires cleaning and drying the system flow path. The steps of cleaning and drying the system flow path include: Step S5: The second liquid delivery unit 12 draws a predetermined amount of extract from the third container 30 and delivers it to the second container 20. The predetermined amount here can preferably be 30 ml.

[0035] Step S6: Switching valve 101 operates, and gas source and flow control module 102 delivers a predetermined amount of purge gas, such as nitrogen, to the second container 20 for bubble cleaning for a third predetermined time; preferably, gas source and flow control module 102 sets 50 sccm of nitrogen and delivers nitrogen to the second container 20 for bubble cleaning for 60s.

[0036] Step S7: After step S6, i.e., after cleaning is completed, the fourth liquid delivery unit 14 operates for a fourth predetermined time to deliver the waste liquid in the second container 20 to the fifth container 50 (repeating the above cleaning operation three times). The predetermined time here can preferably be 10 seconds.

[0037] Step S8: The gas source and flow control module 102 uses nitrogen to continuously purge and dry the system flow path and the second container 20. In this preferred embodiment, the gas source and flow control module 102 sets the nitrogen flow rate to 50 sccm for 300 seconds.

[0038] The apparatus and method provided in this application can greatly save labor costs and improve preparation efficiency. Using a specially designed DNPH powder column, a specified amount of DNPH powder can be quantitatively set to participate in the reaction, making DNPH less prone to agglomeration and producing aldehyde and ketone compound absorbent solutions with low blank DNPH and high loading. Automated preparation is achieved, and the reagents and raw materials are isolated from the human body, making it health-friendly.

[0039] In the description of this specification, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] Although preferred embodiments of this application have been described, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Thus, these modifications and variations are also within the protection scope of this application.

Claims

1. An apparatus for preparing an absorbent solution of aldehydes and ketones, characterized in that, include: The first container is used to hold the acid solution; A powder column for containing DNPH powder, comprising at least two detachably connected short columns; The second container is used to hold the absorbent liquid; The first pipeline connects the first container and the powder column, and is equipped with a first liquid delivery unit for delivering the acid solution in the first container to the powder column; The second pipeline connects the powder column and the second container.

2. The apparatus as claimed in claim 1, characterized in that, Also includes: The third container is used to hold the extract; The fourth container is used to hold the purified saturated absorbent solution; The third pipeline connects the third container and the second container, and is equipped with a second liquid delivery unit for delivering the extract from the third container to the second container; The fourth pipeline connects the second and fourth containers and is equipped with a third liquid delivery unit for delivering the purified absorption liquid from the second container to the fourth container.

3. The apparatus as described in claim 1, characterized in that, Also includes: The gas source and flow control module provides purge gas for bubbling and mixing. A switching valve is installed on the second pipeline, which selectively connects the gas source to the flow control module or the powder column into the flow path.

4. The apparatus as claimed in claim 2, characterized in that, Also includes: The fifth container is used to hold waste liquid; The fourth liquid transfer unit connects the second container and the fifth container and is used to transfer the waste liquid in the second container to the fifth container.

5. The apparatus as claimed in claim 1, characterized in that, It also includes a first gas purification device, which is installed on the second container.

6. The apparatus as claimed in claim 1, characterized in that, It also includes a second gas purification device, which is installed on the fourth container.

7. The apparatus as claimed in claim 1, characterized in that, The connecting surface of the short column is provided with a sieve plate.

8. A method for preparing an aldehyde-ketone compound absorbent, comprising using the apparatus as described in any one of claims 1 to 7 to prepare the aldehyde-ketone compound absorbent, characterized in that, The method includes: Step S1: The first liquid delivery unit draws a predetermined amount of acid solution from the first container and delivers it to the second container through the powder column; Step S2: The second liquid delivery unit draws a predetermined amount of extract from the third container and delivers it into the second container; Step S3: The gas source and flow control module are connected to the flow path to deliver a predetermined amount of purge gas to the second container for bubbling and extraction for the first predetermined time; Step S4: The third liquid delivery unit starts working for the second predetermined time and delivers the purified DNPH absorbent to the fourth container.

9. The method as described in claim 8, characterized in that, The process after step S4 includes cleaning and drying the flow path.

10. The method as described in claim 9, characterized in that, The cleaning and drying steps include: Step S5: The second liquid delivery unit draws a predetermined amount of extract from the third container and delivers it to the second container; Step S6: The air source and flow control module delivers a predetermined amount of purge air to the second container for bubble cleaning for a third predetermined time; Step S7: The fourth liquid delivery unit operates for a fourth predetermined time to deliver the waste liquid in the second container to the fifth container.

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