Solid-phase extraction agent, preparation method and application thereof

Abstract

The invention discloses a solid-phase extraction agent, a preparation method and application thereof, tobacco stems are adopted as a raw material of the solid-phase extraction agent, the tobacco stem material is natural, wide in source and low in price, surface fibers of purified tobacco stem coarse powder subjected to acid treatment and macromolecular impurity removal are exposed, the surface contains a large number of hydroxyl groups, and the contact surface is increased; according to the present invention, the bisphenol substance in water has the hydrophilic property and the ion exchange performance, can interact with a lot of organic and inorganic substances, and solves the problems of various materials, general biocompatibility and high time cost required by the high-multiple enrichment pretreatment of the bisphenol substance in water at present.

Description

Technical Field

[0001] The invention relates to a solid phase extractant, a preparation method and application thereof, and belongs to the technical field of multi-purpose utilization of tobacco. Background Art

[0002] The analysis of trace components in complex matrices is a common issue faced by many fields, including clinical drug testing, early diagnosis of diseases, toxicology analysis, doping control, addictive drug testing, food additive testing, and environmental pollutant monitoring. Since the sample matrix is ​​very complex and the content of the tested components is low, pretreatment to purify the sample and enrich the tested components is an indispensable step. At present, the main methods for determining bisphenols in water are liquid chromatography-tandem mass spectrometry and liquid chromatography-fluorescence detection. Both methods require high-multiple enrichment pretreatment of bisphenols in water. The pretreatment materials use common alkyl bonded phases such as C2, C8, C18, etc., which require many materials, have average biocompatibility, and are time-consuming and costly. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a solid phase extractant, a preparation method and an application thereof, using tobacco stems with exposed surface fibers (containing a large number of hydroxyl groups on the surface) and increased contact surface after purification as the raw material of the solid phase extractant, which has hydrophilicity and ion exchange properties and can interact with many organic and inorganic substances, thereby solving the current problems of a large number of materials required for high-multiple enrichment pretreatment of bisphenols in water, general biocompatibility and high time cost.

[0004] In order to achieve the above purpose / solve the above technical problems, the present invention is implemented by adopting the following technical solutions: In one aspect, the present invention provides a method for preparing a solid phase extraction agent, comprising: The tobacco stems are ground, added with an organic solvent, heated under reflux, washed, and vacuum dried to obtain tobacco stem coarse powder; The tobacco stem crude powder is subjected to acid treatment, filtered and macromolecular impurities are removed, and then vacuum dried to obtain a solid phase extractant.

[0005] Furthermore, the step of grinding the tobacco stems, adding an organic solvent, heating and refluxing, and washing the tobacco stems comprises: The tobacco stems are ground and placed in a filter paper tube, and then an organic solvent is added to perform the first heating reflux and washing; After adding the organic solvent into the filter paper tube again, heating, refluxing and washing are performed for the second time.

[0006] Furthermore, the organic solvent includes methanol and acetone; The organic solvent added in the first heating and reflux is methanol, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to methanol is 50g:200mL-500mL; The organic solvent added in the second heating reflux is acetone, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to acetone is 50g:200mL-500mL.

[0007] Furthermore, the first heating reflux temperature is 60-80° C., and the heating time is 8-24 hours; The second heating reflux temperature is 55-65° C., and the heating time is 8-24 hours.

[0008] Furthermore, the acid treatment of the tobacco stem powder followed by filtering and removal of macromolecular impurities comprises: transferring the tobacco stem powder to a container, adding phosphoric acid, heating and stirring, filtering, and washing with water, acetone, and a strong base in sequence.

[0009] Furthermore, the phosphoric acid is 5% (V / V) phosphoric acid, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to the phosphoric acid is 50g:100mL-200mL.

[0010] Furthermore, the strong base includes NaOH or KOH or a combination of NaOH and KOH, and the concentration of the strong base is 0.5-2 mol / L.

[0011] Furthermore, the solid-liquid mass volume ratio of the tobacco stem coarse powder to water, acetone and strong alkali is 50g:100mL~200mL.

[0012] Another aspect of the present invention provides the use of the above-mentioned solid phase extractant in the detection of bisphenols in lake water.

[0013] Furthermore, the application of the above-mentioned solid phase extractant in the detection of bisphenols in lake water and the method for detecting bisphenols in lake water include: preparing a sample solution including bisphenol A, bisphenol B and bisphenol AF; Placing the solid phase extraction agent as a filler in an empty column tube to obtain a solid phase extraction column; activating the extraction column with acetonitrile and pure water in sequence to obtain an activated solid phase extraction column; Taking an appropriate amount of the sample solution and adding it into the activated solid phase extraction column; Cleaning and eluting the activated solid phase extraction column to obtain an eluate; After the eluate is centrifuged and blown dry, an organic solvent is added to re-dissolve it to obtain a liquid to be tested on the machine; Detect the test liquid on the machine.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts tobacco stems as raw materials for solid phase extraction. Tobacco stem materials are natural, widely available, and inexpensive. The crude tobacco stem powder has been subjected to acid treatment and purification to remove macromolecular impurities. The surface fibers are exposed, the surface contains a large number of hydroxyl groups, and the contact surface is increased. It has hydrophilicity and ion exchange properties and can interact with many organic and inorganic substances. This solves the problem that the current high-multiple enrichment pretreatment of bisphenols in water requires a large number of materials, has general biocompatibility, and has a high time cost.

[0015] 2. The acid-treated tobacco stem filler in the present invention contains abundant ducts and fiber structures, and has the characteristics of good permeability and fast column speed compared to the existing commercially available SPE columns. There is no need to vacuum extract the solution, and the solution to be analyzed can automatically flow down through the tobacco stem filler solid phase extraction column by gravity alone, reducing the required equipment and processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a scanning electron microscope image of a common tobacco stem; Figure 2 is a scanning electron microscope image of a solid phase extractant prepared by a method for preparing a solid phase extractant in an embodiment of the present invention; Figure 3 It is a flow chart of a method for detecting bisphenols in lake water provided by an example of the present invention; Figure 4 A method for preparing a solid phase extractant provided in an example of the present invention is used to prepare a solid phase extraction column using the solid phase extractant as filler; Figure 5 The present invention is an extraction chromatographic separation diagram of the solid phase extractant prepared by the preparation method of the present invention for detecting bisphenol substances in lake water. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention. Example

[0018] A method for preparing a solid phase extractant, comprising: The tobacco stems are ground, added with an organic solvent, heated under reflux, and washed, and vacuum dried to obtain tobacco stem coarse powder, wherein the tobacco stems are ground, added with an organic solvent, heated under reflux, and washed, comprising: The tobacco stems are ground and placed in a filter paper tube, and then an organic solvent is added to perform the first heating reflux and washing; After adding the organic solvent to the filter paper tube again, heating reflux and washing are performed for the second time; wherein the organic solvent added for the first heating reflux is methanol, the solid-liquid mass volume ratio of the tobacco stem coarse powder to methanol is 50g:200mL~500mL, the first heating reflux temperature is 60~80°C, and the heating time is 8~24h; in this embodiment, the first heating reflux adopts heating reflux at 60°C for 16 hours, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to methanol is 50g:200mL; The organic solvent added in the second heating and reflux is acetone, the solid-liquid mass volume ratio of the tobacco stem coarse powder to acetone is 50g:200mL~500mL, the second heating and reflux temperature is 55~65°C, and the heating time is 8~24h; in this embodiment, the second heating and reflux adopts 55°C heating and reflux for 16 hours, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to acetone is 50g:200mL; Specific: The tobacco stems are ground with a grinder to a coarse powder of 10-50 meshes, and the tobacco stem coarse powder is wrapped with three layers of medium-speed filter paper and placed in a Soxhlet extraction filter paper cylinder; Add 200 mL of methanol in a solid-liquid mass volume ratio of 50 g:200 mL to the Soxhlet extraction filter paper tube, heat and reflux at 60°C for 16 hours, add acetone in a solid-liquid mass volume ratio of 50 g:200 mL to the Soxhlet extraction filter paper tube after washing, heat and reflux at 55°C for 16 hours, take out the tobacco stem powder after washing, and vacuum dry it at 60°C.

[0019] The tobacco stem powder is treated with acid, filtered and macromolecular impurities are removed, and vacuum dried to obtain a solid phase extractant, including: Transfer the tobacco stem coarse powder to a container, add phosphoric acid, heat and stir, filter and wash with water, acetone and strong alkali in turn, wherein the phosphoric acid is 5% (V / V) phosphoric acid, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to the phosphoric acid is 50g:100mL-200mL; the strong alkali includes NaOH or KOH or a combination of NaOH and KOH, and the concentration of the strong alkali is 0.5-2 mol / L; in this example, the solid-liquid mass volume ratio of the tobacco stem coarse powder to the phosphoric acid is 50g:100mL, and the strong alkali is 0.5mol / NaOH; Specific: Transfer the tobacco stem powder to a round-bottom flask and add 5% (V / V) phosphoric acid and 85% (V / V) H3PO4, heat and stir at 70°C for 24 h; After filtering, wash with water, acetone, 2 mol / L hydrochloric acid, 0.5 mol / NaOH, water, ethanol, and acetone in order to remove macromolecular impurities such as pigments and proteins on the surface of tobacco leaves; The solid phase extractant was obtained by vacuum drying at 60°C and storing at room temperature; like Figure 1 and Figure 2As shown, the tobacco stem powder, after being treated with acid and purified to remove macromolecular impurities, has exposed surface fibers, contains a large number of hydroxyl groups on the surface and has an increased contact area. It has hydrophilicity and ion exchange properties and can interact with many organic and inorganic substances. Example

[0020] like Figure 3 As shown, a method for detecting bisphenols in lake water comprises: Prepare the sample solution including bisphenol A, bisphenol B and bisphenol AF, specifically: Take 1 mL of 1 mg / mL standard solution of bisphenol A, bisphenol B, and bisphenol AF in a 100 mL volumetric flask, add lake water to make up to volume, and prepare a 10 µg / mL spiked solution as the sample solution for later use; The solid phase extraction agent is placed as a filler in an empty column tube to obtain a solid phase extraction column. Specifically: like Figure 4 As shown, 150 mg of the solid phase extraction agent prepared in Example 1 was accurately weighed, and the weighed solid phase extraction agent was added to a 6 mL SPE empty column tube with a sieve plate, and the tube was continuously tapped to make it evenly filled, and the sieve plate was covered on the upper end and pressed tightly to obtain a solid phase extraction column; The extraction column was activated with 3 mL of acetonitrile and pure water in turn to obtain an activated solid phase extraction column: Add 1 mL of the above-mentioned loading solution to the activated solid phase extraction column and allow it to slowly flow through the activated extraction column under the action of gravity; Use 1 mL of pure water as a washing solution and pass it through the extraction column under gravity to remove the residual matrix adsorbed on the column; Finally, 6 mL of acetonitrile was used as the eluent, and flowed through the extraction column under gravity. The eluate was collected in a 10 mL centrifuge tube, dried by heating at 40 °C with a nitrogen blower, and re-dissolved with 1 mL of methanol to obtain the liquid to be tested on the machine; The test liquid was tested and analyzed according to the method recommended by GB / T 5750.8-2023. The results are shown in Table 1. Example

[0021] A method for preparing a solid phase extractant, comprising: The tobacco stems are ground, added with an organic solvent, heated under reflux, and washed, and vacuum dried to obtain tobacco stem coarse powder, wherein the tobacco stems are ground, added with an organic solvent, heated under reflux, and washed, comprising: The tobacco stems are ground and placed in a filter paper cylinder, and then an organic solvent is added to perform the first heating reflux and washing; After adding the organic solvent to the filter paper tube again, heating, refluxing and washing are performed for the second time, wherein: The organic solvent added in the first heating reflux is methanol, the solid-liquid mass volume ratio of the tobacco stem coarse powder to methanol is 50g:200mL-500mL, the first heating reflux temperature is 60-80°C, and the heating time is 8-24h; The organic solvent added in the second heating reflux is acetone, the solid-liquid mass volume ratio of the tobacco stem coarse powder to acetone is 50g:200mL-500mL, the second heating reflux temperature is 55-65°C, and the heating time is 8-24h; In this embodiment, the first heating reflux is heated at 80°C for 16 hours, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to methanol is 50g:500mL; the second heating reflux is heated at 65°C for 16 hours, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to acetone is 50g:500mL. Specifically: The tobacco stems are ground with a grinder to a coarse powder of 10-50 meshes, and the tobacco stem coarse powder is wrapped with three layers of medium-speed filter paper and placed in a Soxhlet extraction filter paper cylinder; Add 500 mL of methanol in a solid-liquid mass volume ratio of 50 g to the tobacco stem crude powder to the Soxhlet extraction filter paper tube, heat and reflux at 80°C for 16 hours, add 500 mL of acetone in a solid-liquid mass volume ratio of 50 g to the tobacco stem crude powder to the Soxhlet extraction filter paper tube after washing, heat and reflux at 65°C for 16 hours, take out the tobacco stem crude powder after washing, and vacuum dry it at 60°C.

[0022] The tobacco stem powder is treated with acid, filtered and macromolecular impurities are removed, and vacuum dried to obtain a solid phase extractant, including: Transfer the tobacco stem powder to a container, add phosphoric acid, heat and stir, filter and wash with water, acetone and strong alkali in sequence, wherein the phosphoric acid is 5% (V / V) phosphoric acid, and the solid-liquid mass volume ratio of the tobacco stem powder to the phosphoric acid is 50g:100mL-200mL; the strong alkali includes NaOH or KOH or a combination of NaOH and KOH, and the concentration of the strong alkali is 0.5-2 mol / L; In this example, the solid-liquid mass volume ratio of tobacco stem coarse powder to phosphoric acid is 50g:200mL, and the strong base is 2mol / NaOH. Specifically: Transfer the tobacco stem powder to a round-bottom flask and add 5% (V / V) phosphoric acid and 85% (V / V) H3PO4, heat and stir at 70°C for 24 h; After filtering, wash with water, acetone, 2 mol / L hydrochloric acid, 2 mol / L NaOH, water, ethanol, and acetone in order to remove macromolecular impurities such as pigments and proteins on the surface of tobacco leaves; The solid phase extractant was obtained by vacuum drying at 60°C and storing at room temperature. Example

[0023] A method for detecting bisphenols in lake water, comprising: Prepare the sample solution including bisphenol A, bisphenol B and bisphenol AF, specifically: Take 1 mL of 1 mg / mL standard solution of bisphenol A, bisphenol B, and bisphenol AF in a 100 mL volumetric flask, add lake water to make up to volume, and prepare a 10 µg / mL spiked solution as the sample solution for later use; The solid phase extraction agent is placed as a filler in an empty column tube to obtain a solid phase extraction column. Specifically: Accurately weigh 150 mg of the solid phase extraction agent prepared in Example 3, add the weighed solid phase extraction agent to a 6 mL SPE empty column tube with a sieve plate, tap it continuously to make it evenly filled, cover the upper end with the sieve plate and press it tightly to obtain a solid phase extraction column; The extraction column was activated with 3 mL of acetonitrile and pure water in turn to obtain an activated solid phase extraction column: Add 1 mL of the above-mentioned loading solution to the activated solid phase extraction column and allow it to slowly flow through the activated extraction column under the action of gravity; Use 1 mL of pure water as a washing solution and pass it through the extraction column under gravity to remove the residual matrix adsorbed on the column; Finally, 6 mL of acetonitrile was used as the eluent, and flowed through the extraction column under gravity. The eluate was collected in a 10 mL centrifuge tube, dried by heating at 40 °C with a nitrogen blower, and re-dissolved with 1 mL of methanol to obtain the liquid to be tested on the machine; The test liquid was tested and analyzed according to the method recommended by GB / T 5750.8-2023. The results are shown in Table 1. Comparative Example 1: A commercially available HLB solid phase extraction column was used for solid phase extraction, and the sample solution prepared in Example 2 was taken for detection and analysis according to the method recommended by GB / T5750.8-2023. The results are shown in Table 1; Comparative Example 2: A commercially available C18 solid phase extraction column was used for solid phase extraction. The sample solution prepared in Example 2 was tested and analyzed according to the method recommended by GB / T5750.8-2023. The results are shown in Table 1. Comparative Example 3: A commercially available SCX solid phase extraction column was used for solid phase extraction. The sample solution prepared in Example 2 was tested and analyzed according to the method recommended by GB / T5750.8-2023. The results are shown in Table 1.

[0024]

[0025] Table 1 As shown in Table 1 and Figure 5 As shown, the methods proposed in Examples 2 and 4 of the present invention have a higher recovery rate for detecting bisphenol pollutants in lake water. At the same time, the solid phase extraction filler of the present invention has good permeability to the object to be analyzed, a fast column speed, and improved detection efficiency due to its rich duct and fiber structure.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a solid phase extractant, characterized in that: include: The tobacco stems are ground, added with an organic solvent, heated under reflux, washed, and vacuum dried to obtain tobacco stem coarse powder; The tobacco stem crude powder is subjected to acid treatment, filtered and macromolecular impurities are removed, and then vacuum dried to obtain a solid phase extractant.

2. The method for preparing a solid phase extractant according to claim 1, characterized in that: The step of grinding the tobacco stems, adding an organic solvent, heating, refluxing and washing the tobacco stems comprises: The tobacco stems are ground and placed in a filter paper tube, and then an organic solvent is added to perform the first heating reflux and washing; After adding the organic solvent into the filter paper tube again, heating, refluxing and washing are performed for the second time.

3. The method for preparing a solid phase extractant according to claim 2, characterized in that: The organic solvent includes methanol and acetone; The organic solvent added in the first heating and reflux is methanol, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to methanol is 50g:200mL-500mL; The organic solvent added in the second heating reflux is acetone, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to acetone is 50g:200mL-500mL.

4. The method for preparing a solid phase extractant according to claim 2, characterized in that: The first heating reflux temperature is 60-80°C and the heating time is 8-24h; The second heating reflux temperature is 55-65° C., and the heating time is 8-24 hours.

5. The method for preparing a solid phase extractant according to claim 1, characterized in that: The method of subjecting the tobacco stem coarse powder to acidic treatment and then filtering and removing macromolecular impurities comprises: transferring the tobacco stem coarse powder to a container, adding phosphoric acid, heating and stirring, filtering, and washing with water, acetone, and a strong base in sequence.

6. The method for preparing a solid phase extractant according to claim 5, characterized in that: The phosphoric acid is 5% (V / V) phosphoric acid, and the solid-liquid mass volume ratio of the tobacco stem coarse powder to the phosphoric acid is 50g:100mL-200mL.

7. The method for preparing a solid phase extractant according to claim 5, characterized in that: The strong base includes NaOH or KOH or a combination of NaOH and KOH, and the concentration of the strong base is 0.5-2 mol / L.

8. The method for preparing a solid phase extractant according to claim 5, characterized in that: The solid-liquid mass volume ratio of the tobacco stem coarse powder to water, acetone and strong alkali is 50g:100mL-200mL.

9. Use of the solid phase extractant according to claim 1 in the detection of bisphenols in lake water.

10. The use according to claim 9, characterized in that: The detection methods of bisphenols in lake water include: preparing a sample solution including bisphenol A, bisphenol B and bisphenol AF; Placing the solid phase extraction agent as a filler in an empty column tube to obtain a solid phase extraction column; activating the extraction column with acetonitrile and pure water in sequence to obtain an activated solid phase extraction column; Taking an appropriate amount of the sample solution and adding it into the activated solid phase extraction column; Cleaning and eluting the activated solid phase extraction column to obtain an eluate; After the eluate is centrifuged and blown dry, an organic solvent is added to re-dissolve it to obtain a liquid to be tested on the machine; Detect the test liquid on the machine.

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