Petrochemical product analysis method based on cucurbituril

Abstract

The invention discloses a petrochemical product analysis method based on cucurbituril, and relates to the field of analysis of petrochemical products of cucurbituril, and the method comprises the following steps: S1, sample pretreatment; s2, interaction analysis of cucurbituril and a target analyte; and S3, data processing and analysis. According to the petrochemical product analysis method based on cucurbituril, when the petrochemical product is analyzed by adopting an ultraviolet-visible spectrum method, the operation is simple, convenient and rapid, the method is easy to master, the analysis speed is high, a large amount of spectrum information can be obtained in a short time, samples can be rapidly subjected to preliminary screening and qualitative analysis, the analysis efficiency is improved, and the method is suitable for popularization and application. According to the present invention, the petrochemical product analysis is performed by using the fluorescence spectrometry, such that the extremely high sensitivity is provided, the sensitivity of the fluorescence spectrometry is higher than the sensitivity of the ultraviolet-visible spectrometry, the extremely low-concentration fluorescent material can be detected, and even the picomole-level or lower detection limit can be achieved; the method has unique advantages on trace analysis and detection of trace substances in organisms.

Description

Technical Field

[0001] The invention relates to the analysis field of petrochemical products of cucurbituril, and in particular to a petrochemical product analysis method based on cucurbituril. Background Art

[0002] Cucurbituril is a type of macrocyclic compound composed of glycoside urea units connected by methylene bridges. It is shaped like a gourd. From the appearance, cucurbituril is shaped like a gourd. It is a barrel-shaped cyclic compound with a large middle and small openings at both ends. The cavity is surrounded by carbonyl groups and has a rigid structure. The molecular structure is very rigid and cannot change its shape to suit the guest molecule. Therefore, its coordination effect with the guest molecule has extremely strong specificity and an extremely high association constant.

[0003] When analyzing petrochemical products based on cucurbituril, lower concentrations of fluorescent substances cannot be detected, which makes it inconvenient for trace analysis and detection and analysis of trace substances in organisms. At the same time, during the measurement process, most samples require complex pretreatment and chemical reactions, which may damage the structure and properties of the samples, making it inconvenient for subsequent further research and other analytical tests on the samples. Summary of the invention

[0004] The main purpose of the present invention is to provide a petrochemical product analysis method based on cucurbituril, which can effectively solve the problems in the background technology.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A petrochemical product analysis method based on cucurbituril comprises the following steps:

[0007] S1: Sample pretreatment, extraction: Weigh the petrochemical product sample, place it in a stoppered glass container, add an organic solvent to fully dissolve and disperse the sample, and take it out as the extract;

[0008] Purification: passing the extract through a solid phase extraction column filled with silica gel and Florisil, adsorbing impurities in the petrochemical product sample, including but not limited to polar compounds, metal ions, and substances that interact with cucurbituril, which flow out with the eluent, collecting the effluent, washing the extraction column with a solvent, combining the washing liquid and the effluent, and then concentrating the solution to near dryness using a rotary evaporator at 40°C and reduced pressure, and then diluting to a suitable volume with a solvent for subsequent analysis;

[0009] S2: Analysis of the interaction between cucurbituril and target analytes, including the following steps:

[0010] S201: Prepare cucurbituril solution. Accurately weigh cucurbituril and dissolve it in buffer solution to prepare 1×10 -3 mol / L cucurbituril stock solution, and then dilute it to 1×10 -5 -1×10 -4 mol / L;

[0011] S202: taking the treated sample solution and the cucurbituril solution and mixing them in a sealed quartz cuvette or sample bottle, the volume ratio of the sample solution to the cucurbituril solution is 1:10, incubating the mixed solution at 37° C. for 30 minutes to ensure that the cucurbituril and the target analyte fully form an inclusion complex or interact with each other. During the incubation process, magnetic stirring and oscillation are used to mix the solution evenly;

[0012] S203: Detecting the interaction, including UV-visible spectroscopy: Scanning the incubated solution on a UV-visible spectrophotometer with a detection wavelength range of 200-800 nm, observing the changes in the absorption peak position, intensity, etc. of the target analyte in the sample in the presence of cucurbituril. When the target analyte is an aromatic hydrocarbon compound, its absorption peak may be red-shifted or blue-shifted, and the absorption intensity may be changed after the addition of cucurbituril. By analyzing these spectral change characteristics, the type and degree of interaction between cucurbituril and the target analyte can be preliminarily determined;

[0013] Fluorescence spectroscopy: For target analytes with fluorescence characteristics, a fluorescence spectrometer is used for detection. The excitation wavelength and emission wavelength are determined according to the fluorescence characteristics of the target analytes. For some polycyclic aromatic hydrocarbons, the excitation wavelength is set between 250-350nm, and the emission wavelength is in the range of 350-500nm. The fluorescence emission spectra of the target analytes at different cucurbituril concentrations are recorded, and the changes in fluorescence intensity are analyzed. When the fluorescence intensity increases, it is judged that the molecular environment of the target analyte has changed due to the inclusion complex of cucurbituril, reducing non-radiative transitions; when the fluorescence intensity decreases, it is judged that the formed inclusion complex causes fluorescence quenching;

[0014] S3: Data processing and analysis, drawing spectrum change curves based on the data of UV-visible spectrum or fluorescence spectrum, including but not limited to the absorption intensity versus cucurbituril concentration change curve and the fluorescence intensity versus cucurbituril concentration change curve;

[0015] Fitting the data using a suitable mathematical model, including but not limited to using the Langmuir adsorption isotherm and the Scatchard equation, to calculate the binding constant (K) and the number of binding sites (n) of the interaction, which are used to quantitatively describe the interaction strength and binding mode between cucurbituril and the target analyte;

[0016] By comparing the interaction parameters between target analytes and cucurbituril in different petrochemical product samples, the composition and structural differences of petrochemical products as well as the content of certain key components therein can be analyzed and evaluated. For gasoline samples from different batches, when there are significant differences in the interaction parameters between aromatic compounds and cucurbituril, it reflects the difference in their aromatic content or aromatic structure, thus providing a basis for quality control and process optimization of petrochemical products.

[0017] Preferably, in S1, for petrochemical product samples containing heavy hydrocarbons and additives, reflux extraction is performed at 60°C for 2 hours, and magnetic stirring is performed to dissolve and disperse the sample. When the extract passes through the solid phase extraction column, it passes at a flow rate of 1-2 mL / min.

[0018] Preferably, in S201, the buffer solution is a phosphate buffer solution with a pH value of 5-9.

[0019] Preferably, in S203, the UV-visible spectroscopy method specifically includes the following operating steps:

[0020] S20301: Select instruments, use UV-Vis spectrophotometer, ensure the instrument is working properly and calibrated;

[0021] S20302: Set parameters, according to the properties of the sample and experimental requirements, set the appropriate wavelength range, scanning speed and slit width;

[0022] S20303: Measure the sample, put the sample solution into a cuvette, put it into the sample chamber of the spectrophotometer, perform spectral scanning, and record the absorbance value of the sample at different wavelengths;

[0023] S20304: Data analysis: data analysis and processing are performed based on the measured spectral data to draw an absorbance-wavelength curve and determine the maximum absorption wavelength and absorbance value of the sample;

[0024] S20306: Result interpretation: Based on the spectral characteristics of the sample and combined with the known spectral data of the compound, the structure and properties of the sample are explained and inferred.

[0025] Preferably, in S203, the fluorescence spectroscopy method includes the following steps:

[0026] S20307: Select instruments, use fluorescence spectrophotometer, ensure the instrument works properly and calibrate;

[0027] S20308: Set parameters, according to the properties of the sample and experimental requirements, set the appropriate excitation wavelength, emission wavelength range, scanning speed and slit width;

[0028] S20309: Measure the sample, put the sample solution into a fluorescence cuvette, put it into the sample chamber of the spectrophotometer, perform fluorescence spectrum scanning, and record the fluorescence intensity values ​​of the sample at different emission wavelengths;

[0029] S20310: Data analysis: perform data analysis and processing based on the measured fluorescence spectrum data, draw a fluorescence intensity-emission wavelength curve, and determine the maximum fluorescence emission wavelength and fluorescence intensity value of the sample;

[0030] S20311: Result interpretation: Based on the fluorescence spectral characteristics of the sample and combined with the fluorescence spectral data of known compounds, the structure and properties of the sample are explained and inferred.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] In the present invention, when the ultraviolet-visible spectroscopy is used to analyze petrochemical products, the operation is simple and fast, easy to use, and the analysis speed is fast. A large amount of spectral information can be obtained in a short time, and the sample can be quickly preliminarily screened and qualitatively analyzed, thereby improving the analysis efficiency. At the same time, the sensitivity is high, and for some compounds with a conjugated system, such as aromatic compounds, samples with lower concentrations can be detected, and the detection limit can reach the microgram or even nanogram level, which can meet the needs of trace substance detection. The selectivity is good, and different compounds have their own unique ultraviolet-visible absorption spectra. By analyzing the spectral characteristics, compounds with similar structures can be distinguished and Identification, to achieve selective detection of specific substances; non-destructive analysis of samples. During the measurement process, samples usually do not require complex pretreatment or chemical reactions, and can be directly spectrally scanned without causing damage to the structure and properties of the samples, which is convenient for subsequent further research or other analytical tests on the samples; qualitative and quantitative analysis can be performed. According to the shape of the absorption spectrum, the maximum absorption wavelength, the absorption intensity and other characteristics, the unknown samples can be qualitatively analyzed to determine the types of compounds that may exist in the samples. At the same time, by establishing appropriate quantitative analysis methods, such as the standard curve method, the ratio method, etc., the content of the target compound in the sample can be accurately determined.

[0033] Fluorescence spectroscopy is used to analyze petrochemical products with extremely high sensitivity. The sensitivity of fluorescence spectroscopy is higher than that of UV-visible spectroscopy, and it can detect extremely low concentrations of fluorescent substances, even reaching a detection limit of picomolar or lower. It has unique advantages for trace analysis and detection of trace substances in organisms; good selectivity, the emission wavelength and excitation wavelength of the fluorescence spectrum have a certain correspondence, and the fluorescence spectrum characteristics of different substances are significantly different, which makes fluorescence spectroscopy highly selective for fluorescent substances, and can effectively identify and detect target fluorescent substances in complex sample systems and reduce interference; it provides rich information. In addition to fluorescence intensity, fluorescence spectra can also provide a variety of parameter information such as fluorescence emission wavelength, fluorescence lifetime, fluorescence polarization, etc. These parameters can reflect the molecular structure, microenvironment and intermolecular interaction of fluorescent substances. Information on interactions, etc., helps to gain a deep understanding of the properties and change processes of the samples, and provides a powerful means for studying the relationship between the structure and function of substances; it is sensitive to changes in the microenvironment. The fluorescence characteristics of fluorescent substances are easily affected by surrounding environmental factors, such as temperature, pH value, solvent polarity, etc. Therefore, by observing changes in the fluorescence spectrum, the changes in the microenvironment in which the sample is located can be monitored in real time, which is of great significance for studying the conformational changes of biomacromolecules, chemical reaction kinetics, and environmental monitoring. Non-destructive testing, unlike some analytical methods that require chemical reactions or physical destruction of samples, fluorescence spectroscopy usually only requires the sample to be placed under excitation light for detection, which will not cause substantial damage to the sample, which is conducive to the analysis of precious samples or samples that are difficult to prepare, and multiple measurements can be performed without affecting the original properties of the sample. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention relates to a petrochemical product analysis method based on cucurbituril, comprising the following operating steps:

[0036] S1: Sample pretreatment, extraction: Weigh the petrochemical product sample, place it in a stoppered glass container, add an organic solvent to fully dissolve and disperse the sample, and take it out as the extract. For petrochemical product samples containing heavy hydrocarbons and additives, reflux extraction is performed at 60°C for 2 hours, and magnetic stirring is performed to dissolve and disperse the sample. When the extract passes through the solid phase extraction column, it passes at a flow rate of 1-2mL / min;

[0037] Purification: passing the extract through a solid phase extraction column filled with silica gel and Florisil, adsorbing impurities in the petrochemical product sample, including but not limited to polar compounds, metal ions, and substances that interact with cucurbituril, which flow out with the eluent, collecting the effluent, washing the extraction column with a solvent, combining the washing liquid and the effluent, and then concentrating the solution to near dryness using a rotary evaporator at 40°C and reduced pressure, and then diluting to a suitable volume with a solvent for subsequent analysis;

[0038] S2: Analysis of the interaction between cucurbituril and target analytes, including the following steps:

[0039] S201: Prepare cucurbituril solution. Accurately weigh cucurbituril and dissolve it in buffer solution to prepare 1×10 - 3 mol / L cucurbituril stock solution, and then dilute it to 1×10 -5 -1×10 -4 mol / L, the buffer solution is phosphate buffer, pH value is 5-9;

[0040] S202: taking the treated sample solution and the cucurbituril solution and mixing them in a sealed quartz cuvette or sample bottle, the volume ratio of the sample solution to the cucurbituril solution is 1:10, incubating the mixed solution at 37° C. for 30 minutes to ensure that the cucurbituril and the target analyte fully form an inclusion complex or interact with each other. During the incubation process, magnetic stirring and oscillation are used to mix the solution evenly;

[0041] S203: Detecting the interaction, including UV-visible spectroscopy: Scanning the incubated solution on a UV-visible spectrophotometer with a detection wavelength range of 200-800nm, observing the changes in the absorption peak position, intensity, etc. of the target analyte in the sample in the presence of cucurbituril. When the target analyte is an aromatic hydrocarbon compound, its absorption peak may be red-shifted or blue-shifted, and the absorption intensity may be changed after the addition of cucurbituril. By analyzing these spectral change characteristics, the type and degree of interaction between cucurbituril and the target analyte can be preliminarily determined. The specific operation steps include the following:

[0042] S20301: Select instruments, use UV-Vis spectrophotometer, ensure the instrument is working properly and calibrated;

[0043] S20302: Set parameters, according to the properties of the sample and experimental requirements, set the appropriate wavelength range, scanning speed and slit width;

[0044] S20303: Measure the sample, put the sample solution into a cuvette, put it into the sample chamber of the spectrophotometer, perform spectral scanning, and record the absorbance value of the sample at different wavelengths;

[0045] S20304: Data analysis: data analysis and processing are performed based on the measured spectral data to draw an absorbance-wavelength curve and determine the maximum absorption wavelength and absorbance value of the sample;

[0046] S20306: Result interpretation: Based on the spectral characteristics of the sample and combined with the known spectral data of the compound, the structure and properties of the sample are explained and inferred;

[0047] Fluorescence spectroscopy: For target analytes with fluorescence characteristics, a fluorescence spectrometer is used for detection. The excitation wavelength and emission wavelength are determined according to the fluorescence characteristics of the target analyte. For some polycyclic aromatic hydrocarbons, the excitation wavelength is set between 250-350nm, and the emission wavelength is in the range of 350-500nm. The fluorescence emission spectra of the target analytes at different cucurbituril concentrations are recorded, and the changes in fluorescence intensity are analyzed. When the fluorescence intensity increases, it is judged that the molecular environment of the target analyte has changed due to the inclusion complex of cucurbituril, reducing non-radiative transitions; when the fluorescence intensity decreases, it is judged that the formed inclusion complex causes fluorescence quenching. The following steps are included:

[0048] S20307: Select instruments, use fluorescence spectrophotometer, ensure the instrument works properly and calibrate;

[0049] S20308: Set parameters, according to the properties of the sample and experimental requirements, set the appropriate excitation wavelength, emission wavelength range, scanning speed and slit width;

[0050] S20309: Measure the sample, put the sample solution into a fluorescence cuvette, put it into the sample chamber of the spectrophotometer, perform fluorescence spectrum scanning, and record the fluorescence intensity values ​​of the sample at different emission wavelengths;

[0051] S20310: Data analysis: perform data analysis and processing based on the measured fluorescence spectrum data, draw a fluorescence intensity-emission wavelength curve, and determine the maximum fluorescence emission wavelength and fluorescence intensity value of the sample;

[0052] S20311: Result interpretation: Based on the fluorescence spectrum characteristics of the sample and combined with the known fluorescence spectrum data of the compound, the structure and properties of the sample are explained and inferred;

[0053] S3: Data processing and analysis, drawing spectrum change curves based on the data of UV-visible spectrum or fluorescence spectrum, including but not limited to the absorption intensity versus cucurbituril concentration change curve and the fluorescence intensity versus cucurbituril concentration change curve;

[0054] Fitting the data using a suitable mathematical model, including but not limited to using the Langmuir adsorption isotherm and the Scatchard equation, to calculate the binding constant (K) and the number of binding sites (n) of the interaction, which are used to quantitatively describe the interaction strength and binding mode between cucurbituril and the target analyte;

[0055] By comparing the interaction parameters between target analytes and cucurbituril in different petrochemical product samples, the composition and structural differences of petrochemical products as well as the content of certain key components therein can be analyzed and evaluated. For gasoline samples from different batches, when there are significant differences in the interaction parameters between aromatic compounds and cucurbituril, it reflects the difference in their aromatic content or aromatic structure, thus providing a basis for quality control and process optimization of petrochemical products.

[0056] The method of the present invention is compared with the method of the prior art, the present invention is recorded as an embodiment, and the prior art is recorded as a comparative example. The following is a comparison table:

[0057]

[0058] This shows that the analysis success rate of this method is higher.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A petrochemical product analysis method based on cucurbituril, characterized in that: The steps include: S1: Sample pretreatment, extraction: Weigh the petrochemical product sample, place it in a stoppered glass container, add an organic solvent to fully dissolve and disperse the sample, and take it out as the extract; Purification: passing the extract through a solid phase extraction column filled with silica gel and Florisil, adsorbing impurities in the petrochemical product sample, including but not limited to polar compounds, metal ions, and substances that interact with cucurbituril, which flow out with the eluent, collecting the effluent, washing the extraction column with a solvent, combining the washing liquid and the effluent, and then concentrating the solution to near dryness using a rotary evaporator at 40°C and reduced pressure, and then diluting to a suitable volume with a solvent for subsequent analysis; S2: Analysis of the interaction between cucurbituril and target analytes, including the following steps: S201: Prepare cucurbituril solution. Accurately weigh cucurbituril and dissolve it in buffer solution to prepare 1×10 -3 mol / L cucurbituril stock solution, and then dilute it to 1×10 -5 -1×10 -4 mol / L; S202: taking the treated sample solution and the cucurbituril solution and mixing them in a sealed quartz cuvette or sample bottle, the volume ratio of the sample solution to the cucurbituril solution is 1:10, incubating the mixed solution at 37° C. for 30 minutes to ensure that the cucurbituril and the target analyte fully form an inclusion complex or interact with each other. During the incubation process, magnetic stirring and oscillation are used to mix the solution evenly; S203: Detecting the interaction, including UV-visible spectroscopy: Scanning the incubated solution on a UV-visible spectrophotometer with a detection wavelength range of 200-800 nm, observing the changes in the absorption peak position, intensity, etc. of the target analyte in the sample in the presence of cucurbituril. When the target analyte is an aromatic hydrocarbon compound, its absorption peak may be red-shifted or blue-shifted, and the absorption intensity may be changed after the addition of cucurbituril. By analyzing these spectral change characteristics, the type and degree of interaction between cucurbituril and the target analyte can be preliminarily determined; Fluorescence spectroscopy: For target analytes with fluorescence characteristics, a fluorescence spectrometer is used for detection. The excitation wavelength and emission wavelength are determined according to the fluorescence characteristics of the target analytes. For some polycyclic aromatic hydrocarbons, the excitation wavelength is set between 250-350nm, and the emission wavelength is in the range of 350-500nm. The fluorescence emission spectra of the target analytes at different cucurbituril concentrations are recorded, and the changes in fluorescence intensity are analyzed. When the fluorescence intensity increases, it is judged that the molecular environment of the target analyte has changed due to the inclusion complex of cucurbituril, reducing non-radiative transitions; when the fluorescence intensity decreases, it is judged that the formed inclusion complex causes fluorescence quenching; S3: Data processing and analysis, drawing spectrum change curves based on the data of UV-visible spectrum or fluorescence spectrum, including but not limited to the absorption intensity versus cucurbituril concentration change curve and the fluorescence intensity versus cucurbituril concentration change curve; Fitting the data using a suitable mathematical model, including but not limited to using the Langmuir adsorption isotherm and the Scatchard equation, to calculate the binding constant (K) and the number of binding sites (n) of the interaction, which are used to quantitatively describe the interaction strength and binding mode between cucurbituril and the target analyte; By comparing the interaction parameters between target analytes and cucurbituril in different petrochemical product samples, the composition and structural differences of petrochemical products as well as the content of certain key components therein can be analyzed and evaluated. For gasoline samples from different batches, when there are significant differences in the interaction parameters between aromatic compounds and cucurbituril, it reflects the difference in their aromatic content or aromatic structure, thus providing a basis for quality control and process optimization of petrochemical products.

2. A petrochemical product analysis method based on cucurbituril according to claim 1, characterized in that: In S1, for a petrochemical product sample containing heavy hydrocarbons and additives, reflux extraction is performed at 60° C. for 2 hours, and magnetic stirring is performed to dissolve and disperse the sample. When the extract passes through the solid phase extraction column, it passes at a flow rate of 1-2 mL / min.

3. The petrochemical product analysis method based on cucurbituril according to claim 1, characterized in that: In the S201, the buffer solution is a phosphate buffer solution with a pH value of 5-9.

4. The petrochemical product analysis method based on cucurbituril according to claim 1, characterized in that: In S203, the UV-visible spectroscopy method specifically includes the following operating steps: S20301: Select instruments, use UV-Vis spectrophotometer, ensure the instrument is working properly and calibrated; S20302: Set parameters, according to the properties of the sample and experimental requirements, set the appropriate wavelength range, scanning speed and slit width; S20303: Measure the sample, put the sample solution into a cuvette, put it into the sample chamber of the spectrophotometer, perform spectral scanning, and record the absorbance value of the sample at different wavelengths; S20304: Data analysis: data analysis and processing are performed based on the measured spectral data to draw an absorbance-wavelength curve and determine the maximum absorption wavelength and absorbance value of the sample; S20306: Result interpretation: Based on the spectral characteristics of the sample and combined with the known spectral data of the compound, the structure and properties of the sample are explained and inferred.

5. The petrochemical product analysis method based on cucurbituril according to claim 1, characterized in that: In S203, the fluorescence spectroscopy method includes the following steps: S20307: Select instruments, use fluorescence spectrophotometer, ensure the instrument works properly and calibrate; S20308: Set parameters, according to the properties of the sample and experimental requirements, set the appropriate excitation wavelength, emission wavelength range, scanning speed and slit width; S20309: Measure the sample, put the sample solution into a fluorescence cuvette, put it into the sample chamber of the spectrophotometer, perform fluorescence spectrum scanning, and record the fluorescence intensity values ​​of the sample at different emission wavelengths; S20310: Data analysis: perform data analysis and processing based on the measured fluorescence spectrum data, draw a fluorescence intensity-emission wavelength curve, and determine the maximum fluorescence emission wavelength and fluorescence intensity value of the sample; S20311: Result interpretation: Based on the fluorescence spectral characteristics of the sample and combined with the fluorescence spectral data of known compounds, the structure and properties of the sample are explained and inferred.

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