Rapid detection system and method for benzo(a)pyrene in oil
By developing an electrochemiluminescence preparation method and an electrochemiluminescence detection system, the cumbersome pretreatment problem in the detection of benzo(a)pyrene in oils and fats has been solved, achieving rapid, accurate, and economical detection results.
Patent Information
- Application Number
- CN202310124415.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-16
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2043-02-16
AI Technical Summary
Existing methods for detecting benzo(a)pyrene in oils and fats require cumbersome pretreatment steps and have high equipment costs, which limits their widespread use and application.
An electrochemiluminescence detection system without pretreatment was constructed by using an electrochemiluminescence preparation method, combining N,N-dimethylformamide as a background reagent, 1-butyl-3-methylimidazolium hexafluorophosphate ion solution as a supporting electrolyte, and tri-n-propylamine as a co-reactant. Rapid detection was performed using an electrochemiluminescence-electroluminescence analyzer.
It enables rapid and accurate detection of benzo(a)pyrene in oils and fats, simplifies the operation process, reduces detection costs, and is suitable for front-line applications.
Smart Images
Figure CN116067947B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to electrochemical detection technology, and more specifically, to a novel rapid detection system and method for detecting benzo(a)pyrene in oils and fats. Background Technology
[0002] Benzo(a)pyrene is an aromatic hydrocarbon compound and one of the three major carcinogens recognized by the World Health Organization, possessing extremely strong carcinogenic, embryotoxic, and mutagenic effects. Its toxicity exceeds that of aflatoxin, posing a significant threat to human health. Furthermore, due to its insolubility in water and slight soluble in organic solvents, it readily accumulates in adipose tissue, causing irreversible and severe damage to various organs. Benzo(a)pyrene in oils mainly originates from oilseed crop production processes, oilseed pretreatment processes, oil extraction processes, oil storage and transportation processes, and oil usage processes. The non-industrialized standard production methods in numerous small workshops and incorrect oil usage practices also increase the potential for benzo(a)pyrene to harm public health.
[0003] Currently, commonly used methods for detecting benzo(a)pyrene include high-performance liquid chromatography (HPLC), Raman spectroscopy, gas chromatography-mass spectrometry (GC-MS), and immunoassay. However, these methods are mostly laboratory-based techniques, requiring specialized equipment and operators. Furthermore, the detection of benzo(a)pyrene in oils typically involves cumbersome pretreatment processes such as extraction and purification of the sample. While the HPLC method used in the current national standard (GB 5009.27-2016) boasts a low detection limit and reliable accuracy, its high instrument procurement and maintenance costs, along with its relatively high barrier to entry, limit its widespread adoption. Therefore, developing a rapid, accurate, and cost-effective method for detecting benzo(a)pyrene in oils that requires no cumbersome pretreatment is essential. Summary of the Invention
[0004] The purpose of this invention is to provide a rapid, accurate, and relatively economical detection system and method for benzo(a)pyrene in oils and fats that requires no complicated pretreatment.
[0005] One embodiment of the present invention adopts the following technical solution:
[0006] 1. Preparation of electrochemiluminescent materials
[0007] 1.1 Synthesis of Electrochemiluminescent Materials
[0008] Dichlorobis(2,2'-bipyridine)ruthenium dihydrate and dipyridophenezine were dissolved in an appropriate amount of ethylene glycol and stirred under reflux for 12-18 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature and filtered. Ammonium hexafluorophosphate was added to the filtrate. After the precipitate was formed, the mixture was filtered again and the filtrate was collected for use.
[0009] During the preparation process, the molar ratio of dichlorobis(2,2'-bipyridine)ruthenium dihydrate and dipyridophenezine is 1:1-2, and the molar ratio of ammonium hexafluorophosphate to dichlorobis(2,2'-bipyridine)ruthenium dihydrate is 1:1-2.
[0010] 1.2 Purification of electrochemiluminescent materials
[0011] The filtrate obtained in step 1.1 was purified by silica gel column chromatography. During the separation process, acetonitrile-10w% KNO3 aqueous solution (volume ratio 9:1) was used as the eluent to remove unreacted raw materials during the synthesis process. The purified electrochemiluminescent solution was collected and rotary evaporated in a rotary evaporator until the solid was completely precipitated. The obtained solid was repeatedly washed with distilled water until all residual KNO3 was removed. Finally, the solid was collected to obtain the purified electrochemiluminescent material.
[0012] 2. Establishment of the testing system
[0013] This invention establishes an electrochemiluminescence system that can be directly used for the detection of benzo(a)pyrene in oils and fats. The system uses N,N-dimethylformamide as the background reagent, 1-butyl-3-methylimidazolium hexafluorophosphate ion solution as the supporting electrolyte, tri-n-propylamine as the co-reactant, a glassy carbon electrode polished with Al2O3 powder and a platinum electrode as the working and counter electrodes, an Ag / AgCl electrode with a 0.025 mol / L 1-butyl-3-methylimidazolium hexafluorophosphate acetonitrile solution as the internal reference solution as the reference electrode, and a purified electrochemiluminescent agent as the specific recognition substance for benzo(a)pyrene.
[0014] Thanks to the excellent solubility of N,N-dimethylformamide in oils and fats and the specific recognition of benzo(a)pyrene by the electrochemiluminescent material, this system can achieve quantitative detection of benzo(a)pyrene content in oils and fats without any pretreatment.
[0015] The background detection reagent N,N-dimethylformamide is used to dissolve 1-butyl-3-methylimidazolium hexafluorophosphate to form an ionic solution, which serves as the supporting electrolyte.
[0016] Furthermore, in the electrochemiluminescence system, the background detection reagent is N,N-dimethylformamide, the concentration of the electrochemiluminescent agent is 90-110 μmol / L, the concentration of the supporting electrolyte 1-butyl-3-methylimidazolium hexafluorophosphate is 0.2-1.0 mmol / L, and the concentration of the co-reactant tri-n-propylamine is 20-160 μmol / L.
[0017] 3. A novel rapid detection method for benzo(a)pyrene
[0018] Based on the above-mentioned electrochemiluminescence system, this invention provides a novel rapid detection method for benzo(a)pyrene in oils and fats. The steps are as follows: the oil sample to be tested is mixed evenly with N,N-dimethylformamide in the electrochemiluminescence system, the volume ratio of the oil sample to N,N-dimethylformamide is 0.5-2:9, then other components of the electrochemiluminescence system, including supporting electrolyte, co-reaction reagent, and electrochemiluminescent agent, are added to the mixed solution to obtain the test system, and the test system is subjected to electrochemical performance testing.
[0019] Furthermore, basic electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer (Xi'an Ruimai MPI-E) using cyclic voltammetry at a scan rate of 150 mV / s.
[0020] The technical solution of the present invention will be further described below.
[0021] This invention designs and synthesizes a specific electrochemiluminescent (ECL) emitter for the electrochemiluminescence detection of benzo(a)pyrene, using dipyridophenezine and dichlorobis(2,2'-bipyridine)ruthenium dihydrate as raw materials. This ECL emitter achieves specific recognition of benzo(a)pyrene; upon contact with benzo(a)pyrene, the electrochemiluminescence signal originally generated by the ECL emitter is quenched, and this quenching is linearly correlated with the logarithm of the benzo(a)pyrene concentration. Furthermore, the ECL emitter exhibits stable electroluminescence properties, maintaining relative stability in its chemical properties and electrochemiluminescence signal during long-term detection.
[0022] This invention selects N,N-dimethylformamide, which can dissolve oils, as a background reagent to replace acetonitrile. However, potassium tetra(4-p-chlorophenyl)borate has poor solubility in N,N-dimethylformamide. To provide a stable ion source for the detection system, 1-butyl-3-methylimidazolium hexafluorophosphate ion solution is used instead of potassium tetra(4-p-chlorophenyl)borate as the supporting electrolyte. Through these optimizations, the solubility of oils in the detection system is improved while maintaining the original detection capability, thereby enabling the direct detection of benzo(a)pyrene in oils.
[0023] This invention, based on a classic three-electrode system, utilizes N,N-dimethylformamide as the background reagent, 1-butyl-3-methylimidazolium hexafluorophosphate ion solution as the supporting electrolyte, and tri-n-propylamine as the co-reactant to construct a rapid detection method for benzo(a)pyrene in oils without cumbersome pretreatment. The method has a detection limit of 2.45 nmol / L and a linear range of 50 nmol / L–10 μmol / L, enabling rapid and direct detection of benzo(a)pyrene in oils. Compared to the liquid chromatography method used in national standards, this method is simpler to operate and more suitable for first-line detection.
[0024] Compared with the prior art, the present invention has at least the following beneficial effects:
[0025] The electrochemiluminescence system provided by this invention can be directly used for the detection of benzo(a)pyrene in oils and fats without the need for complicated pretreatment. It has a fast detection speed, high accuracy of detection results, and simple operation. Attached Figure Description
[0026] Figure 1 ECL curves for the gradient addition of benzo(a)pyrene in the acetonitrile-potassium tetrakis(4-p-chlorophenyl)borate system.
[0027] Figure 2 The cyclic voltammetry curves are shown before and after the addition of benzo(a)pyrene.
[0028] Figure 3 Electrochemiluminescence curves before and after the addition of benzo(a)pyrene.
[0029] Figure 4 Electrochemiluminescence intensity-time curves before and after the addition of benzo(a)pyrene.
[0030] Figure 5 The effects of different interfering substances on the detection of benzo(a)pyrene.
[0031] Figure 6 The electrochemiluminescence intensity varies with the concentration of benzo(a)pyrene.
[0032] Figure 7 The figure shows the change in electrochemiluminescence intensity quenching rate as a function of benzo(a)pyrene concentration, with the inset showing the linear fit plot and equation of quenching rate versus the logarithm of benzo(a)pyrene concentration.
[0033] Figure 8 It is the state in which acetonitrile and DMF are added to the oil separately without shaking.
[0034] Figure 9 It is the state of the oil after adding acetonitrile and DMF respectively, and then shaking and letting it stand. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0036] Example 1: Preparation of Electrochemiluminescent Materials
[0037] Dichlorobis(2,2'-bipyridine)ruthenium dihydrate and dipyridophenezine were dissolved in an appropriate amount of ethylene glycol at a molar ratio of 1:1. The mixture was stirred and refluxed under nitrogen protection for 15 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. Ammonium hexafluorophosphate was added to the filtrate at a molar ratio of 1:1 to the ruthenium dihydrate. After the precipitate was formed, the mixture was filtered again and the filtrate was collected for use. The filtrate was purified using silica gel column chromatography. During the separation process, an acetonitrile-10w% KNO3 aqueous solution (volume ratio 9:1) was used as the eluent to remove unreacted raw materials from the synthesis process. The purified electrochemiluminescent solution was collected and subjected to rotary evaporation in a rotary evaporator until the solid was completely precipitated. The obtained solid was repeatedly washed with distilled water until all residual KNO3 was removed. Finally, the solid was collected to obtain the purified electrochemiluminescent material. The obtained luminescent material was used in the examples, comparative examples, and subsequent experiments.
[0038] Detection Examples
[0039] Comparative Example 1
[0040] First, an alarm system was constructed based on a classic three-electrode system, using acetonitrile as the background reagent, potassium tetrakis(4-p-chlorophenyl)borate as the supporting electrolyte, tri-n-propylamine as the co-reactant, a glassy carbon electrode and a platinum electrode polished with Al2O3 powder as the working electrode and counter electrode, an Ag / AgCl electrode as the reference electrode, and the electrochemiluminescent material prepared in Example 1 as a benzo(a)pyrene specific recognition substance. In this system, the concentration of the electrochemiluminescent material was 100 μmol / L; the concentration of potassium tetrakis(4-p-chlorophenyl)borate was 1.0 mmol / L; and the concentration of tri-n-propylamine was 100 μmol / L.
[0041] Benzo(a)pyrene was added to the detection system to prepare test samples a to g, wherein the concentration of benzo(a)pyrene in test sample a was 0 μmol / L, and the concentrations of benzo(a)pyrene in test samples b, c, d, e, f, and g were 5 μmol / L, 10 μmol / L, 15 μmol / L, 20 μmol / L, 30 μmol / L, and 40 μmol / L, respectively.
[0042] Basic electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer (Xi'an Ruimai MPI-E) using cyclic voltammetry at a scan rate of 150 mV / s.
[0043] Experimental test results are as follows Figure 1 As shown, it can be seen that as the concentration of benzo(a)pyrene in the system increases, the electrochemiluminescence intensity gradually decreases and exhibits a certain linearity, indicating that quantitative detection of benzo(a)pyrene can be achieved in the system of this comparative example.
[0044] Add acetonitrile and DMF to two test tubes respectively, then add equal amounts of soybean oil (from the Key Laboratory of Coarse Grain Processing, Ministry of Agriculture and Rural Affairs) to two different test tubes respectively. Figure 8 As shown, after adding the oil, without shaking, the oil in the acetonitrile test tube settled to the bottom of the acetonitrile, while the oil in the DMF test tube remained suspended on the surface of the DMF. After thoroughly shaking the test tubes to ensure the oil, acetonitrile, and DMF were mixed evenly, and allowed to stand for one minute, as shown... Figure 9 As shown, obvious oil precipitation appeared at the bottom of the acetonitrile test tube, while the oil and DMF in the DMF test tube remained dissolved, with no oil suspended on the surface of the DMF. The above experiment reveals that the system using acetonitrile as the background reagent has the disadvantage of poor oil dissolution, which significantly hinders the direct detection of benzo(a)pyrene in oils.
[0045] Example 2
[0046] An electrochemiluminescence (ECL) system was prepared using N,N-dimethylformamide as the background reagent, 1-butyl-3-methylimidazolium hexafluorophosphate (1-butyl-3-methylimidazolium hexafluorophosphate) ion solution as the supporting electrolyte, tri-n-propylamine as the co-reactant, a glassy carbon electrode polished with Al₂O₃ powder and a platinum electrode as the working and counter electrodes, an Ag / AgCl electrode with a 0.025 mol / L 1-butyl-3-methylimidazolium hexafluorophosphate acetonitrile solution as the internal reference solution, and a purified electrochemiluminescent material as the specific recognition substance for benzo(a)pyrene. In this system, N,N-dimethylformamide was used as the background reagent, the concentration of the electrochemiluminescent material was 100 μmol / L, the concentration of 1-butyl-3-methylimidazolium hexafluorophosphate was 1.0 mmol / L, and the concentration of tri-n-propylamine was 100 μmol / L.
[0047] Basic electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer (Xi'an Ruimai MPI-E) using cyclic voltammetry at a scan rate of 150 mV / s. In this example, 10 μmol / L benzo(a)pyrene-N,N-dimethylformamide solution was added to the detection system, and the changes in cyclic voltammetry and electrochemiluminescence curves before and after the addition were observed. The results are as follows: Figure 2 , Figure 3 As shown. By Figure 2 It is known that the electrochemiluminescent material itself has an oxidation peak with a peak potential of around 1.25 V. However, after the addition of benzo(a)pyrene, a new oxidation peak appears at a potential of around 1.0 V, which is the oxidation peak of benzo(a)pyrene. Throughout the process, the current intensity remains at a relatively low level. In contrast, from... Figure 3It can be seen that after the addition of benzo(a)pyrene, the relative electrochemiluminescence signal intensity in the system decreased sharply by more than 50%, indicating that benzo(a)pyrene can effectively quench the original electrochemiluminescence signal intensity in the detection system. The above results show that in the detection system of this embodiment, it is possible to detect benzo(a)pyrene by analyzing either the cyclic voltammetry curve or the change in the quenching rate of the electrochemiluminescence signal, but analyzing the change in the quenching rate of the electrochemiluminescence signal obviously has better sensitivity.
[0048] Investigating the reliability of detection methods
[0049] 0.25 mmol of dichlorobis(2,2'-bipyridine)ruthenium dihydrate and 0.25 mmol of dipyridylphenazine were dissolved in 20 mL of ethylene glycol, and the mixture was stirred and refluxed under nitrogen protection for 15 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. 0.25 mmol of ammonium hexafluorophosphate was added to the filtrate, and after the precipitate formed, it was filtered again. The filtrate was then collected for use.
[0050] The filtrate was purified by silica gel column chromatography, with acetonitrile-10w% KNO3 (volume ratio 9:1) used as the eluent throughout the process. Unreacted raw materials were removed by silica gel column chromatography. The purified electrochemiluminescent solution was collected and subjected to low-temperature rotary evaporation until the solid was completely precipitated. The obtained solid was repeatedly washed with distilled water until all KNO3 was removed, and finally the purified electrochemiluminescent material was obtained.
[0051] The ability of this method to detect benzo(a)pyrene in actual oil samples was investigated using a spiking method. Seven commercially available oils (provided by the Key Laboratory of Coarse Grain Processing, Ministry of Agriculture and Rural Affairs, and conforming to the relevant requirements of national standard GB 15196-2015) were used as actual samples. The types of the seven oils are shown in Table 1. Each oil sample was mixed with N,N-dimethylformamide at a volume ratio of 1:9 to form the background solvent. Then, an electrochemiluminescent agent, tri-n-propylamine, and 1-butyl-3-methylimidazolium hexafluorophosphate were added to 2 mL of the background solvent, so that the test system contained 100 μmol / L of electrochemiluminescent agent, 100 μmol / L of tri-n-propylamine, and 1 mmol / L of 1-butyl-3-methylimidazolium hexafluorophosphate. Subsequently, different concentrations of benzo(a)pyrene were added to the system, and the concentrations of added benzo(a)pyrene are shown in Table 1. Basic electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer (Xi'an Ruimai MPI-E) with cyclic voltammetry at a scan rate of 150 mV / s. The calculated value of the added benzo(a)pyrene was obtained based on the change in electrochemical signal intensity after its addition, and the recovery rate was calculated accordingly. The results are shown in Table 1.
[0052] Table 1. Results of Benzo[a]pyrene spiked test in actual oil samples.
[0053]
[0054] Note: The markings in the sample names follow the markings used by the Key Laboratory of Coarse Grain Processing of the Ministry of Agriculture and Rural Affairs for oils.
[0055] As shown in Table 1, the recovery rates of benzo(a)pyrene in the seven edible oils ranged from 94% to 108%, and the relative standard deviations were all below 9%, indicating the reliability of the detection results of this method.
[0056] To investigate the stability of electrochemiluminescence and the anti-interference ability of the detection system.
[0057] A fixed amount of benzo(a)pyrene was added to 2 mL of N,N-dimethylformamide containing 100 μmol / L electrochemiluminescence, 100 μmol / L tri-n-propylamine, and 1 mmol / L 1-butyl-3-methylimidazolium hexafluorophosphate ion solution. Basic electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer (Xi'an Ruimai MPI-E) by cyclic voltammetry. The electrochemiluminescence signal intensity was recorded during the test, and the scan rate was maintained at 150 mV / s throughout the process.
[0058] Figure 4 The changes in light signal intensity during 10 consecutive electrochemiluminescence tests before and after the addition of benzo(a)pyrene were shown, with the amount of benzo(a)pyrene added fixed at 2.5 μmol / L in each test. It can be seen that without the addition of benzo(a)pyrene, the electrochemiluminescence intensity obtained in the 10 tests was high and basically consistent, indicating that the electrochemiluminescent material prepared in this invention has good and stable electrochemiluminescence performance. After the addition of benzo(a)pyrene, the electroluminescence signal decreased significantly, but the intensity remained stable in the 10 consecutive tests, indicating that the benzo(a)pyrene detection system constructed in this invention has good stability and detection reliability.
[0059] Eight detection systems were prepared by adding 50 μmol / L benzo(a)pyrene to 2 mL of N,N-dimethylformamide containing 100 μmol / L electrochemiluminescence, 100 μmol / L tri-n-propylamine, and 1 mmol / L 1-butyl-3-methylimidazolium hexafluorophosphate ion solution. One interfering substance (AA, V) was added to each of the eight detection systems. E TBHQ, CH, Pb 2+ Cr 3+ Cd 2+ and Hg 2 +Except for TBHQ, which was 500 μmol / L, the concentrations of other interfering substances were all 0.5 mmol / L. Basic electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer (Xi'an Ruimai MPI-E) by cyclic voltammetry. The intensity of the electrochemiluminescence signal was recorded during the test, and the scan rate was maintained at 150 mV / s throughout the process.
[0060] Figure 5 This exhibit showcases cyclohexane (CH), a commonly used extraction solvent in oil and fat preparation; tert-butylhydroquinone (TBHQ), an antioxidant widely present in oils and fats; and other substances that may be present in oils and fats (AA, V). E Pb 2+ Cr 3+ Cd 2+ and Hg 2 + The effect on the intensity of electrochemiluminescence signal. From Figure 5 It can be seen that the interference of common substances in oils, such as vitamin E, ascorbic acid, and various harmful metal ions, on the intensity of the electrochemiluminescence signal in the detection system is negligible. This indicates that the benzo(a)pyrene detection system constructed in this invention is not affected by other substances present in oils and has reliable anti-interference ability.
[0061] The detection limit and linear range of the benzo(a)pyrene detection system constructed in this invention
[0062] In a detection system consisting of 2 mL of N,N-dimethylformamide in 100 μmol / L electrochemiluminescence, 100 μmol / L tri-n-propylamine, and 1 mmol / L 1-butyl-3-methylimidazolium hexafluorophosphate ion solution, a concentration gradient test (benzo[a]pyrene concentration from 50 nmol / L to 15 μmol / L) was performed to determine the relationship between the electrochemiluminescence signal intensity and the benzo[a]pyrene concentration. The test method used was cyclic voltammetry at a scan rate of 150 mV / s. The test results are as follows: Figure 6 As shown, the electrochemiluminescence signal intensity continuously decreases with increasing benzo(a)pyrene concentration. Data analysis revealed that the quenching rate of the electrochemiluminescence signal intensity (I0-I / I0) is related to the logarithm of the benzo(a)pyrene concentration (logC). BaP The relationship between the two is linear (where I0 and I represent the electrochemiluminescence signal intensities before and after the addition of benzo(a)pyrene, respectively), and the linear fitting plot is shown in the figure. Figure 7 As shown, the linear equation is I0 - I / I0 = 0.321logC BaP +0.451(R 2=0.987), with a linear range of 50 nmol / L-15 μmol / L. Using a three-fold signal-to-noise ratio, the detection limit for benzo(a)pyrene calculated by this invention is 2.45 nmol / L, which is close to the detection limit of the liquid chromatography method used in my country's national standard (assuming the oil density is tentatively set at 0.93 kg / L, the detection limit of the national standard method is approximately 0.74 nmol / L, and the quantitation limit is 1.84 nmol / L). Compared to the liquid chromatography method in the national standard, the detection method described in this invention has advantages such as simple operation, lower detection cost, and no need for pretreatment of liquid oil samples, making it suitable for more practical applications.
[0063] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.
Claims
1. A rapid detection system for benzo(a)pyrene in oils and fats, characterized in that, A rapid detection system for detecting benzo(a)pyrene in oils and fats was formed by using 1-butyl-3-methylimidazolium hexafluorophosphate ion solution as the supporting electrolyte, N,N-dimethylformamide as the detection background reagent to dissolve 1-butyl-3-methylimidazolium hexafluorophosphate, tri-n-propylamine as the co-reactant, and an electrochemiluminescent material as the specific recognition substance for benzo(a)pyrene. Together with the working electrode, counter electrode, and reference electrode, the system can be used to detect benzo(a)pyrene in oils and fats by electrochemical performance testing methods. The method for preparing the electrochemiluminescent material is as follows: Dichlorobis(2,2'-bipyridine)ruthenium dihydrate and dipyridophenezine were dissolved in an appropriate amount of ethylene glycol and stirred under reflux for 12-18 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature and filtered. Ammonium hexafluorophosphate was added to the filtrate. After the precipitate was formed, the mixture was filtered again and the filtrate was collected for later use. After purification, an electrochemiluminescent material was obtained.
2. The rapid detection system for benzo(a)pyrene in oils and fats according to claim 1, characterized in that, In the rapid detection system, the concentration of the electrochemiluminescent agent is 90-110 μmol / L, the concentration of the supporting electrolyte 1-butyl-3-methylimidazolium hexafluorophosphate is 0.2-1.0 mmol / L, and the concentration of the co-reactant tri-n-propylamine is 20-160 μmol / L.
3. The rapid detection system for benzo(a)pyrene in oils and fats according to claim 1, characterized in that, The method for purifying the electrochemiluminescent material is to use silica gel column chromatography to purify the final filtrate obtained during the preparation of the electrochemiluminescent material. During the separation process, acetonitrile-10w% KNO3 aqueous solution is used as the eluent, with a volume ratio of acetonitrile to 10w% KNO3 aqueous solution of 9:1, in order to remove the raw materials that have not undergone reaction during the synthesis process. The purified electrochemiluminescent material solution is collected and subjected to rotary evaporation in a rotary evaporator until the solid is completely precipitated. The obtained solid is repeatedly washed with distilled water until all residual KNO3 is removed. Finally, the solid is collected to obtain the purified electrochemiluminescent material.
4. The rapid detection system for benzo(a)pyrene in oils and fats according to claim 1, characterized in that, The working electrode is a glassy carbon electrode polished with Al2O3 powder, the counter electrode is a platinum electrode, and the reference electrode is an Ag / AgCl electrode with a 0.025 mol / L acetonitrile solution of 1-butyl-3-methylimidazolium hexafluorophosphate as the internal reference solution.
5. A novel rapid detection method for benzo(a)pyrene in oils and fats, characterized in that, The oil sample to be tested was mixed with N,N-dimethylformamide to obtain a mixed solution. Then, an electrochemiluminescent agent, tri-n-propylamine, and 1-butyl-3-methylimidazolium hexafluorophosphate were added to the mixed solution to obtain the test system. The electrochemical performance of the test system was then tested. The method for preparing the electrochemiluminescent material is as follows: Dichlorobis(2,2'-bipyridine)ruthenium dihydrate and dipyridophenezine were dissolved in an appropriate amount of ethylene glycol and stirred under reflux for 12-18 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature and filtered. Ammonium hexafluorophosphate was added to the filtrate. After the precipitate was formed, the mixture was filtered again and the filtrate was collected for later use. After purification, an electrochemiluminescent material was obtained.
6. The novel rapid detection method for benzo(a)pyrene in oils and fats according to claim 5, characterized in that, The volume ratio of the oil sample to be tested to the N,N-dimethylformamide is 0.5-2:9; in the test system, the concentration of 1-butyl-3-methylimidazolium hexafluorophosphate is 0.2-1.0 mmol / L; the concentration of tri-n-propylamine is 20-160 μmol / L; and the concentration of the electrochemiluminescent agent is 90-110 μmol / L.
7. The novel rapid detection method for benzo(a)pyrene in oils and fats according to claim 5, characterized in that, The electrochemical performance test used glassy carbon electrode and platinum electrode polished with Al2O3 powder as working electrode and counter electrode, respectively, and Ag / AgCl electrode with 0.025 mol / L acetonitrile solution of 1-butyl-3-methylimidazolium hexafluorophosphate as internal reference solution as reference electrode. Electrochemical performance was tested using an electrochemical-electrochemiluminescence analyzer, and the testing method was cyclic voltammetry.
8. The novel rapid detection method for benzo(a)pyrene in oils and fats according to claim 5, characterized in that, The method for purifying and obtaining electrochemiluminescent materials is The final filtrate obtained during the preparation of the electrochemiluminescent material was purified using silica gel column chromatography. During the separation process, acetonitrile-10w% KNO3 aqueous solution was used as the eluent, with a volume ratio of acetonitrile to 10w% KNO3 aqueous solution of 9:1, to remove unreacted raw materials from the synthesis process. The purified electrochemiluminescent material solution was collected and subjected to rotary evaporation in a rotary evaporator until the solid was completely precipitated. The obtained solid was repeatedly washed with distilled water until all residual KNO3 was removed. Finally, the solid was collected to obtain the purified electrochemiluminescent material.