Solid Phase Microextraction Adsorbent for Bis(p-Chlorophenyl)trichloroethane
By preparing covalent organic polymers as solid phase microextraction adsorbents, the problems of insufficient selectivity and adsorption capacity for the detection of bis(p-chlorophenyl)trichloroethane in food were solved, and efficient adsorption and detection of bis(p-chlorophenyl)trichloroethane were achieved.
Patent Information
- Application Number
- CN202310613879.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-29
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2043-05-29
AI Technical Summary
The existing technology lacks solid phase microextraction adsorption materials with high selectivity and adsorption capacity for dichlorophenyltrichloroethane in food.
The invention adopts 2,3,5,6-tetrachloroterephthalaldehyde and 1,3,5-triaminobenzene as reactant monomers, sodium dichloroisocyanurate and trichloroacetic acid as catalysts, and performs a condensation reaction in a solvent to prepare a covalent organic polymer for making a solid phase microextraction probe.
The prepared polymer has good adsorption selectivity and adsorption capacity for bis(p-chlorophenyl)trichloroethane, and can efficiently detect bis(p-chlorophenyl)trichloroethane in food.
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Abstract
Description
Technical Field
[0001] The invention relates to a solid phase microextraction adsorbent of bis(p-chlorophenyl)trichloroethane, in particular to a polymer obtained by condensation reaction of 2,3,5,6-tetrachloroterephthalaldehyde and 1,3,5-triaminobenzene as reactant monomers, belonging to the technical field of pesticide detection. Background Art
[0002] BDCT was first synthesized in 1874, and its insecticidal properties were discovered by Swiss chemists in 1939. In 2002, the World Health Organization announced the reinstatement of BDCT for mosquito control and to prevent the resurgence of malaria, dengue fever, yellow fever, and other diseases worldwide.
[0003] However, the environmental pollution and human harm caused by BCT are clear. Studies have confirmed that BCT can accumulate in animal fat and disrupt hormone secretion. Other studies have shown that it affects human liver function and morphology and has significant carcinogenic properties. Therefore, the detection of BCT in food is extremely important. However, the content of BCT in food is very low, and currently there is no specialized solid-phase microextraction adsorption material. Summary of the Invention
[0004] The purpose of the present invention is to provide a solid phase microextraction adsorbent with high selectivity and adsorption capacity for bis(p-chlorophenyl)trichloroethane.
[0005] The solid-phase microextraction adsorbent described in this invention is a covalent organic polymer obtained by condensing 2,3,5,6-tetrachloroterephthalaldehyde and 1,3,5-triaminobenzene as reactants and a mixture of sodium dichloroisocyanurate and trichloroacetic acid as a catalyst in a solvent. Research has shown that this polymer exhibits excellent adsorption selectivity for bis(p-chlorophenyl)trichloroethane, making it suitable as a solid-phase microextraction adsorbent for bis(p-chlorophenyl)trichloroethane.
[0006] The structure of one reactant monomer 2,3,5,6-tetrachloroterephthalaldehyde of the present invention is shown in Formula I, and the structure of another reactant monomer 1,3,5-triaminobenzene is shown in Formula II.
[0007]
[0008] The specific preparation method of the covalent organic polymer is as follows: a solvent is placed in a reaction kettle, the temperature is raised to 40-60°C, and under continuous stirring, a reactant monomer mixture and a catalyst are added, maintaining a mass ratio of solvent, reactant monomer mixture, and catalyst of (30-40):1:(0.10-0.15), and the reaction is incubated for 5-10 hours; the solid is filtered, washed with the solvent and methanol, respectively, and then vacuum-dried at 50-80°C for 5 hours to obtain a covalent organic polymer having a repeating unit as shown in Formula III. This polymer has a network structure, with each network composed of 12 reactant monomers linked together.
[0009]
[0010] The solvent is one or a mixture of toluene, o-xylene, m-xylene, and p-xylene; the reactant monomer mixture is a mixture of 2,3,5,6-tetrachloroterephthalaldehyde and 1,3,5-triaminobenzene in a molar ratio of 1:1; and the catalyst is a mixture of sodium dichloroisocyanurate and trichloroacetic acid in a molar ratio of 1:3.
[0011] The prepared polymer can be used to make solid-phase microextraction probes. For example, after the stainless steel wire of the solid-phase microextraction device is polished and cleaned, the polymer of the present invention is adhered to the stainless steel wire through a sealant. After curing, a solid-phase microextraction probe with high selectivity and adsorption capacity for bis(p-chlorophenyl)trichloroethane is obtained. DETAILED DESCRIPTION
[0012] Example 1
[0013] m-Xylene was added into a reaction kettle, and the temperature was raised to 50°C. Under continuous stirring, the reactant monomer mixture and the catalyst were added, and the mass ratio of the solvent, the reactant monomer mixture and the catalyst was maintained at 35:1:0.10. The reaction was kept warm for 10 hours. The reaction was carried out after natural cooling, and the solid was filtered out, washed with xylene and methanol respectively, and then vacuum dried at 60°C for 5 hours to obtain a covalent organic polymer.
[0014] Example 2
[0015] Toluene was added into a reaction kettle, and the temperature was raised to 42°C. The reactant monomer mixture and the catalyst were added under continuous stirring, and the mass ratio of the solvent, the reactant monomer mixture and the catalyst was maintained at 35:1:0.10. The reaction was kept warm for 10 hours. The reaction was carried out after natural cooling, and the solid was filtered out, washed with xylene and methanol respectively, and then vacuum dried at 60°C for 5 hours to obtain a covalent organic polymer.
[0016] Example 3
[0017] o-Xylene was placed in a reaction kettle, and the temperature was raised to 40°C. The reactant monomer mixture and the catalyst were added under continuous stirring, and the mass ratio of the solvent, the reactant monomer mixture and the catalyst was maintained at 30:1:0.10. The reaction was kept warm for 6 hours. The reaction was carried out after natural cooling, and the solid was filtered out, washed with xylene and methanol respectively, and then vacuum dried at 50°C for 5 hours to obtain a covalent organic polymer.
[0018] Example 4
[0019] P-xylene was added into a reaction kettle, and the temperature was raised to 45°C. The reactant monomer mixture and the catalyst were added under continuous stirring, and the mass ratio of the solvent, the reactant monomer mixture and the catalyst was maintained at 40:1:0.12. The reaction was kept warm for 7 hours. The reaction was carried out after natural cooling, and the solid was filtered out, washed with xylene and methanol respectively, and then vacuum dried at 70°C for 5 hours to obtain a covalent organic polymer.
[0020] Example 5
[0021] Toluene and o-xylene are added into a reactor in a mass ratio of 1:1, and the temperature is raised to 55°C. Under continuous stirring, the reactant monomer mixture and the catalyst are added, and the mass ratio of the solvent, the reactant monomer mixture and the catalyst is maintained at 38:1:0.15. The reaction is kept warm for 8 hours; the reaction is carried out naturally cooling, and the solid is filtered out, washed with xylene and methanol respectively, and then vacuum dried at 75°C for 5 hours to obtain a covalent organic polymer.
[0022] Example 6
[0023] Toluene and m-xylene are added into a reactor in a mass ratio of 1:1, the temperature is raised to 60°C, and the reactant monomer mixture and the catalyst are added under continuous stirring, maintaining the mass ratio of the solvent, the reactant monomer mixture and the catalyst at 36:1:0.14, and the reaction is kept warm for 9 hours; naturally cooled, the solid is filtered out, washed with xylene and methanol respectively, and then vacuum dried at 65°C for 5 hours to obtain a covalent organic polymer.
[0024] Example 7
[0025] Toluene and p-xylene are added into a reactor in a mass ratio of 1:1, the temperature is raised to 52°C, and the reactant monomer mixture and the catalyst are added under continuous stirring, maintaining the mass ratio of the solvent, the reactant monomer mixture and the catalyst at 32:1:0.11, and the reaction is kept warm for 6 hours; the reaction is carried out naturally cooling, the solid is filtered out, washed with xylene and methanol respectively, and then vacuum dried at 80°C for 5 hours to obtain a covalent organic polymer.
[0026] Example 8
[0027] o-xylene and m-xylene are added into a reactor in a mass ratio of 1:1, and the temperature is raised to 50°C. Under continuous stirring, the reactant monomer mixture and the catalyst are added, and the mass ratio of the solvent, the reactant monomer mixture and the catalyst is maintained at 35:1:0.15. The reaction is kept warm for 5 hours; the reaction is carried out naturally cooling, and the solid is filtered out, washed with xylene and methanol respectively, and then vacuum dried at 50°C for 5 hours to obtain a covalent organic polymer.
[0028] Example 9
[0029] After the stainless steel wire of the solid phase microextraction device was polished and cleaned, a sealant was evenly applied to the front end surface of the stainless steel wire with a length of 2 cm. The polymer prepared in Example 1 was adhered to the stainless steel wire through the sealant and cured to obtain a solid phase microextraction probe.
[0030] Example 10
[0031] 1 gram of apple was weighed and crushed, and 5.0 mL of acetonitrile was added and vortexed for 1 hour. The mixture was filtered and the filtrate was collected. The solid-phase microextraction probe prepared in Example 9 was inserted into the apple extract for solid-phase microextraction adsorption. The solid-phase microextraction probe, which had adsorbed bis(p-chlorophenyl)trichloroethane, was then subjected to GC-ECD analysis using the method described in "Determination of Multicomponent Residues of Organochlorine Pesticides in Foods" (GB / T 5009.19-2008). The gas chromatography thermal desorption temperature was 248°C. The results showed that the bis(p-chlorophenyl)trichloroethane content in the apple was 2.5 ng / g.
[0032] Example 11
[0033] After the stainless steel wire of the solid phase microextraction device was polished and cleaned, a sealant was evenly applied to the front end surface of the stainless steel wire with a length of 2 cm. The polymer prepared in Example 2 was adhered to the stainless steel wire through the sealant and cured to obtain a solid phase microextraction probe.
[0034] Example 12
[0035] Weigh 1 g of corn flour, add 5.0 mL of acetonitrile, vortex for 1 hour, filter, and collect the filtrate. The solid-phase microextraction probe prepared in Example 11 was inserted into the extract and subjected to solid-phase microextraction adsorption. The solid-phase microextraction probe, which had adsorbed bis(p-chlorophenyl)trichloroethane, was then subjected to GC-ECD analysis using the method described in "Determination of Multicomponent Residues of Organochlorine Pesticides in Foods" (GB / T 5009.19-2008). The gas chromatography thermal desorption temperature was 255°C. The results showed that the bis(p-chlorophenyl)trichloroethane content in the corn flour was 1.2 ng / g.
Claims
1. A solid phase microextraction adsorbent for bis(p-chlorophenyl)trichloroethane, characterized in that A polymer is obtained by condensing 2,3,5,6-tetrachloroterephthalaldehyde and 1,3,5-triaminobenzene as reactant monomers. The preparation method comprises the following steps: placing a solvent into a reaction kettle, heating the temperature to 40-60°C, adding a reactant monomer mixture and a catalyst under continuous stirring, maintaining the mass ratio of the solvent, the reactant monomer mixture and the catalyst at (30-40):1:(0.10-0.15), and carrying out the reaction at this temperature for 5-10 hours; filtering out the solid, washing it with a solvent and methanol respectively, and then vacuum drying it at 50-80°C for 5 hours to obtain a covalent organic polymer.
2. A solid phase microextraction adsorbent for bis(p-chlorophenyl)trichloroethane according to claim 1, characterized in that The solvent is one or a mixture of toluene, o-xylene, m-xylene and p-xylene.
3. A solid phase microextraction adsorbent for bis(p-chlorophenyl)trichloroethane according to claim 1, characterized in that The reactant monomer mixture is a mixture of 2,3,5,6-tetrachloroterephthalaldehyde and 1,3,5-triaminobenzene in a molar ratio of 1:
1.
4. A solid phase microextraction adsorbent for bis(p-chlorophenyl)trichloroethane according to claim 1, characterized in that The catalyst is a mixture of sodium dichloroisocyanurate and trichloroacetic acid in a molar ratio of 1:3.