Method for degrading carbamazepine by sodium periodate driven by ultraviolet light

Abstract

The present application relates to a kind of methods for degrading carbamazepine by sodium periodate catalysis driven by ultraviolet light.To the water to be treated containing carbamazepine,1.0mM sodium periodate is added, and irradiated by ultraviolet light with excitation wavelength of 254nm, so as to degrade carbamazepine.Using sodium periodate oxidation alone, ultraviolet photolysis is almost ineffective for degrading carbamazepine, and the combination of sodium periodate and ultraviolet light can effectively degrade carbamazepine. The present application further studies the intermediate product of degrading carbamazepine by sodium periodate catalysis driven by ultraviolet light, and obtains 7 degradation intermediates, which can be used for detecting or evaluating the degradation degree, degradation speed and residual pollution of carbamazepine. The degradation experiment of carbamazepine in actual water body shows that the method of the present application has good stability and is less affected by environmental factors.

Description

Technical Field

[0001] This invention belongs to the field of water pollution control technology, and in particular relates to a method for treating water polluted by pharmaceutical organic compounds, specifically a method for using ultraviolet light to drive the degradation of carbamazepine by sodium periodate. Background Technology

[0002] With societal progress, the production and consumption of pharmaceuticals and personal care products (PPCPs) are increasing daily. As an emerging class of pollutants, PPCPs have become a hot topic and a challenge in environmental research. Carbamazepine (CBZ), a representative example, has been found to be widely present in wastewater treatment plants, surface water, groundwater, and even drinking water. Carbamazepine is a commonly used psychiatric drug, widely used for central nervous system uremia, polyuria, and bipolar disorder, and is a first-line treatment for these conditions. It has a wide range of uses and high consumption worldwide.

[0003] Carbamazepine residues not only have adverse effects on the environment and ecosystems, but can also cause serious threats to human health and organisms through bioaccumulation in the food chain. The main pathways for carbamazepine to enter the environment include: (1) entering the aquatic environment with sewage treatment plants. Carbamazepine has been detected in the effluent of sewage treatment plants and surface water both domestically and internationally; (2) discarded carbamazepine drugs entering the aquatic environment directly or indirectly as solid waste. Due to the high chemical stability of carbamazepine molecules, its removal efficiency in wastewater treatment plants is low. Therefore, it has always been one of the most frequently detected drugs in surface water and groundwater. Carbamazepine can accumulate in organisms, causing biomagnification effects, affecting embryonic development, and causing reproductive and nervous system dysfunction. In addition, acridine, as a typical intermediate in the photolysis process of CBZ, exhibits greater toxicity than the original CBZ.

[0004] Traditional methods for removing carbamazepine include physical and biological methods. Physical methods have low removal rates for trace levels of carbamazepine and require expensive, easily clogged equipment. Biological methods are ineffective because carbamazepine is a nitrogen-containing aromatic heterocyclic compound with a symmetrical structure and tightly bound atoms. Developing efficient treatment methods for removing CBZ and its metabolites is crucial for ensuring water source safety.

[0005] In recent years, water treatment technology based on periodate (PI) activation has emerged as a novel advanced oxidation process (AOPs). During the treatment of recalcitrant organic matter, it generates highly reactive oxygen species (ROS / RIS), such as hydroxyl radicals (·OH), periodate radicals (IO4·), and superoxide radicals (O2·). - Singlet oxygen () 1O2), iodate radicals (IO3·), etc. Studies have shown that there are some transformation processes among free radicals, which are related to the degradation rate of pollutants. However, there is limited research on the degradation mechanism, potential transformation modes, and degradation intermediates of CBZ using UV / NaIO4, which limits the application of UV / NaIO4 in the degradation of carbamazepine. Summary of the Invention

[0006] To address the technical problems of carbamazepine's wide distribution, high hazard, and difficulty in degradation in existing technologies, this invention provides a method for the catalytic degradation of carbamazepine using sodium periodate driven by ultraviolet light. 1.0 mM sodium periodate is added to the water containing carbamazepine, and the water is irradiated with ultraviolet light at an excitation wavelength of 254 nm to degrade the carbamazepine. While sodium periodate oxidation and ultraviolet photolysis alone are almost ineffective in degrading carbamazepine, the combined use of sodium periodate and ultraviolet light can effectively degrade it.

[0007] This invention further investigated the intermediates of carbamazepine degradation catalyzed by ultraviolet light-driven sodium periodate, obtaining seven degradation intermediates that can be used to detect or evaluate the degree of carbamazepine degradation, degradation rate, and residual pollution. Ion interference experiments showed that the natural anion (Cl...) - and SO4 2- The UV / NaIO4 process has little impact on the degradation rate. Carbamazepine degradation experiments in actual water bodies show that the UV / NaIO4 process of this invention has good stability and is less affected by environmental factors.

[0008] Specifically:

[0009] On one hand, the present invention provides a method for the catalytic degradation of carbamazepine by sodium periodate driven by ultraviolet light, characterized in that sodium periodate is added to the water to be treated containing carbamazepine and irradiated with ultraviolet light of wavelength 254nm to promote the oxidative decomposition of carbamazepine.

[0010] Furthermore, the method for the catalytic degradation of carbamazepine by sodium periodate driven by ultraviolet light according to the present invention is characterized in that the reaction is carried out under continuous stirring or shaking conditions, the reaction temperature is maintained at 20-30℃, and the pH value is 6.0-7.0.

[0011] Furthermore, the method for the ultraviolet light-driven sodium periodate catalytic degradation of carbamazepine described in this invention is characterized by a carbamazepine concentration of 20 μM in the water to be treated, a working concentration of 1.0 mM for sodium periodate, and an ultraviolet light irradiation intensity of 7.6 mW·cm. -2 .

[0012] On the other hand, the carbamazepine degradation products produced by the method for ultraviolet light-driven sodium periodate catalytic degradation of carbamazepine provided by the present invention are selected from one or more of the following groups:

[0013] Product 1: C 15 H 12 N2O2;

[0014] Product 2: C 15 H 12 N2O2;

[0015] Product 3: C 14 H9NO2;

[0016] Product 4: C 13 H9N;

[0017] Product 5: C 15 H 14 N2O;

[0018] Product 6: C 14 H 11 NO2;

[0019] Product 7: C 13 H9NO.

[0020] In another aspect, the present invention provides the application of the aforementioned carbamazepine degradation products in detecting or evaluating the degree of carbamazepine degradation, degradation rate, and residual pollution.

[0021] In another aspect, the present invention provides a method for detecting carbamazepine and its degradation products, comprising:

[0022] (1) Carbamazepine was quantitatively analyzed and detected by HPLC;

[0023] (2) Carbamazepine degradation products were identified by tandem high-resolution mass spectrometry;

[0024] The carbamazepine degradation products are generated by the aforementioned ultraviolet light-driven sodium periodate catalytic degradation method for carbamazepine.

[0025] Furthermore, the method for detecting carbamazepine and its degradation products according to the present invention is characterized in that the HPLC mobile phase is a mixture of water and acetonitrile, and the flow rate is 0.8 mL·min. -1 .

[0026] Furthermore, the method for detecting carbamazepine and its degradation products according to the present invention is characterized in that the tandem high-resolution mass spectrometry is performed using Q-TOF in positive ion exchange mode, wherein the TOF-MS cathode electron spray voltage is 5500V, the ion source temperature is 550℃, the collision energy is 10V, the gas pressure is 25psi, and the declustering voltage is 40V; the TOF-MS2 cathode electron spray voltage is 5500V, the ion source temperature is 550℃, the collision energy is 35V, the gas pressure is 25psi, and the declustering voltage is 40V.

[0027] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0028] First, the present invention provides a method for the degradation of carbamazepine by ultraviolet light-driven NaIO4 catalysis. Compared with the degradation by ultraviolet light-driven NaIO4 alone, the removal efficiency of carbamazepine is significantly improved by ultraviolet light-driven NaIO4, with a degradation efficiency of up to 92.1%.

[0029] Second, this invention identifies carbamazepine intermediates produced by the ultraviolet light-driven NaIO4 catalytic degradation method. The seven intermediate products identified by tandem mass spectrometry provide targets for evaluating the degree of degradation and mineralization of carbamazepine.

[0030] Third, this invention investigated the stability of the UV-driven NaIO4 catalytic degradation method for carbamazepine. The results showed that common natural anions in water (Cl...) - and SO4 2- The effect of UV / NaIO4 on the degradation rate is small, indicating that the degradation process has good stability and is less affected by environmental factors. Attached Figure Description

[0031] The above and other objects, features, and advantages of exemplary embodiments of the present disclosure will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the present disclosure are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0032] Figure 1 Degradation results of CBZ in UV-only system, water system, NaIO4-only system, and UV / NaIO4 system.

[0033] Figure 2 A: Cl - Effect of UV-activated sodium periodate on the degradation of carbamazepine

[0034] Figure 2 B: SO4 2- Effect of UV-activated sodium periodate on the degradation of carbamazepine

[0035] Figure 3 Carbamazepine degradation intermediates and degradation pathways

[0036] Figure 4 Degradation rate of carbamazepine by ultraviolet-activated sodium periodate in actual water bodies

[0037] Figure 5 Secondary mass spectrum of carbamazepine degradation intermediate product 1

[0038] Figure 6Secondary mass spectrum of carbamazepine degradation intermediate product 2

[0039] Figure 7 Secondary mass spectra of carbamazepine degradation intermediate products.

[0040] Figure 8 Secondary mass spectra of carbamazepine degradation intermediate product 4

[0041] Figure 9 Secondary mass spectrum of carbamazepine degradation intermediate product 5

[0042] Figure 10 Secondary mass spectrum of carbamazepine degradation intermediate product 6

[0043] Figure 11 Secondary mass spectrum of carbamazepine degradation intermediate product 7 Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example:

[0046] This invention provides a method for ultraviolet light-driven NaIO4 photocatalytic degradation of CBZ and its evaluation, including the following steps:

[0047] S1. Prepare chemical reagents

[0048] Macarzazepine (CBZ, ≥99%), sodium periodate (NaIO4, ≥99%), ethanol, Milli-Q water, acetonitrile (chromatographic grade).

[0049] S2. Dynamics Experiment

[0050] Batch degradation experiments were conducted in a 120 mL cylindrical glass reactor under a low-pressure mercury lamp with an excitation wavelength of 254 nm. Prepared 1.0 mM NaIO4 was added to a reaction system containing 20 μM CBZ. The reaction solution was accelerated at 350 rpm. -1 The solution was continuously stirred at a constant speed. The pH of the solution was adjusted to 6.4, and the experimental temperature was maintained at 25±1℃. Control groups included a single UV irradiation group, a single acidic sulfite group, and a single Milli-Q water group. Samples were collected at specified time intervals (0, 2, 5, 10, 20, 30, and 45 min) and purified using a 0.22 μm polyethersulfone filter. Next, a small amount of ethanol was added to the samples to terminate the free radical reaction.

[0051] Inorganic anions, as common natural components of water, can quench oxides and generate new free radicals with low redox potentials, thereby hindering the elimination of target pollutants. Therefore, this invention considers the common anion Cl... - and SO4 2- The effect on removal rate was investigated by further adding 10 mM, 20 mM, and 40 mM Cl to the test water. - or SO4 2- The effect of UV-driven NaIO4 on the removal rate of CBZ was investigated. All kinetic experiments were conducted under specified reaction conditions.

[0052] Instrumental Analysis of S3.CBZ and its Intermediates

[0053] 1. Quantitative analysis of CBZ using high performance liquid chromatography.

[0054] The mobile phase consisted of ultrapure water and acetonitrile (v / v = 4:6), and the flow rate was 0.8 mL / min. -1 HPLC was used to quantitatively determine the degradation efficiency of CBZ in various systems, and the results are as follows: Figure 1 As shown, after 30 minutes of degradation, only 1.75% and 3.25% of CBZ were degraded in the UV irradiation system and the NaIO4 system, respectively. However, in the UV / NaIO4 system, the degradation efficiency of CBZ reached 92.1%. In conclusion, sodium periodate and ultraviolet light alone have almost no effect on the degradation of carbamazepine. In contrast, UV-activated periodate can significantly improve the removal rate of carbamazepine.

[0055] Different concentrations of Cl - SO4 2- The effect on CBZ removal rate is shown in the following results. Figure 2 As shown. Add 10mM, 20mM and 40mM Cl. - Subsequently, the removal rate of CBZ decreased from 92.1% to 86.45%, 83.95%, and 81.9%. Similarly, the removal rate of SO4... 2- It also inhibits the degradation of CBZ, specifically SO4. 2- At concentrations of 10 mM, 20 mM, and 40 mM, the removal rates of CBZ were 86.75%, 83.45%, and 82.7%, respectively, representing decreases of 5.14%, 8.75%, and 9.57% compared to the control group. In summary, the inorganic anion Cl... - and SO4 2- The system has minimal impact on the carbamazepine removal method provided by this invention, demonstrating that the system can maintain a stable removal effect in application.

[0056] 2. High-resolution mass spectrometry was used to identify the degradation products of CBZ.

[0057] Measurements were performed using Q-TOF in positive ion exchange mode, with the TOF-MS cathode electron spray voltage at 5500 V, ion source temperature at 550 °C, collision energy at 10 V, gas pressure at 25 psi, and declusivity voltage at 40 V. 2 The positive electrode electron spray voltage is 5500V, the ion source temperature is 550℃, the collision energy is 35V, the gas pressure is 25psi, and the declustering voltage is 40V.

[0058] Seven degradation intermediates of carbamazepine were screened and identified using tandem mass spectrometry data. Figure 3 Product 1: C 15 H 12 N2O2; Product 2: C 15 H 12 N2O2; Product 3: C 14 H9NO2; Product 4:

[0059] C 13 H9N; Product 5: C 15 H 14 N2O; Product 6: C 14 H 11 NO2; Product 7: C 13 H9NO( Figures 5-11 ).

[0060] CBZ exhibits two degradation pathways, specifically:

[0061] Pathway I: Alkene double bond (C 11 -C 13 An electron transfer oxidation of the β-chain element in CBZ produces a carbon-centered radical cation, which undergoes hydroxyl substitution to generate product 1 and epoxidized product 2. Notably, the heterocycle in product 1 undergoes dehydration to generate product 2. Product 3 is formed through ring contraction, hydrogen rearrangement, and deamidation of product 2. Product 3 undergoes decarboxylation to generate product 4, and the central heterocycle of product 4 is further oxidized to generate product 7.

[0062] Pathway II: Alkene double bonds in CBZ-centered heterocyclic rings (C 11 -C 13 ) by IO4 - Oxidation product 5 undergoes central heterocycle cleavage and C 11 -C 13 The product 6 undergoes a carboxylation reaction, followed by cyclization and ketation to form product 7.

[0063] S4.CBZ removal efficiency in actual water bodies

[0064] To obtain important information on the actual water bodies in which UV / NaIO4 degrades, natural water samples a, b, and c were obtained from the Pearl River in Guangzhou, Guangdong Province, and basic water body indicators were tested and verified.

[0065] Three natural water samples were collected to investigate the CBZ degradation system in actual water bodies. 20 μM carbamazepine was added to natural water samples a, b, and c, and the degradation efficiency of carbamazepine in the actual water bodies was detected using the UV / NaIO4 method in steps S2 and S3. The results showed that compared with the distilled water control sample containing the same concentration of carbamazepine (degradation rate 92.1%), the overall removal efficiency of CBZ in the actual water bodies was significantly reduced to 77.75%, 47.05%, and 60.4%, respectively. Figure 4 ).

[0066] Analysis of the basic parameters of the three samples revealed that sample b had higher TOC value, turbidity, and organic matter content than samples a and c (Table 1). Furthermore, the high organic matter content may have a strong inhibitory effect on CBZ degradation due to the quenching effect caused by organic matter. Natural organic matter can act as a filter for ultraviolet light, reducing photon absorption. On the other hand, high turbidity also reduces the transmittance within the reaction system, leading to a decrease in CBZ removal efficiency. In conclusion, the pretreatment of anions and natural organic matter in natural water bodies is a crucial step in improving the efficiency of UV / NaIO4 treatment.

[0067] Table 1 Basic parameters of actual water bodies

[0068]

[0069] The preferred embodiments of the present invention have been described above to make the spirit of the present invention clearer and easier to understand, and are not intended to limit the present invention. All modifications, substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope summarized by the appended claims.

Claims

1. A method for the degradation of carbamazepine by sodium periodate catalyzed by UV light, characterized in that, Sodium periodate was added to the water containing carbamazepine, and the water was irradiated with ultraviolet light at a wavelength of 254 nm to promote the oxidative decomposition of carbamazepine. The concentration of carbamazepine in the water was 20 μM, the working concentration of sodium periodate was 1.0 mM, and the ultraviolet light irradiation intensity was 7.6 mW•cm. -2 ; The method produces a carbamazepine degradation product which is one or more selected from the group consisting of: Product 1 : C 15 H 12 N2O2; Product 2: C 15 H 12 N2O2; Product 3: C 14 H9NO2; Product 4: C 13 H9N; Product 5: C 15 H 14 N2O; Product 6: C 14 H 11 NO2; Product 7: C 13 H9NO.

2. The method for ultraviolet light-driven sodium periodate catalytic degradation of carbamazepine as described in claim 1, characterized in that, The reaction is carried out under continuous stirring or shaking, the reaction temperature is maintained at 20-30℃, and the pH value is 6.0-7.0.

Images