Method for detecting azoic coupling component AS-PH production waste gas

Abstract

The invention discloses an azoic coupling component AS-PH production waste gas detection method, and relates to the technical field of environment detection, the method comprises the following steps: constructing a multistage condensation and molecular sieve adsorption combined pretreatment system to realize graded removal of moisture and various interferents in waste gas to obtain purified gas; according to the method, a two-stage series capillary chromatographic column separation system based on the polarity difference principle is constructed, the separation degree of complex components is improved in a programmed heating mode, a mass spectrometry detector is adopted to perform selective scanning and qualitative analysis on multiple characteristic fragment ions of the azoic coupling component AS-PH, and an internal standard method is adopted to perform quantitative analysis; a quantitative analysis system with deuterated azoic coupling component as an internal standard substance is established, the double confirmation advantages of a selective ion monitoring mode and a multiple reaction monitoring channel are combined, high-precision quantitative detection is achieved through a multi-point calibration curve method, and standardized detection of azoic coupling component AS-PH production waste gas is achieved. According to the method, the influence of matrix effect and instrument response drift is effectively eliminated, the measurement result is more reliable, the operation is simple and convenient, and the analysis speed is high.

Description

Technical Field

[0001] The invention relates to the technical field of environmental monitoring, in particular to a method for detecting waste gas produced by naphthol AS-PH. Background Art

[0002] Naphthol AS-PH is an important azo dye intermediate, which is widely used in the production of dye industry. In its production process, waste gas containing Naphthol AS-PH will be generated. If these waste gases are not properly handled, they will cause harm to the environment and human health. At present, the analysis and detection of waste gas from the production of Naphthol AS-PH mainly adopts liquid chromatography, but this method has the disadvantages of complex sample pretreatment, long analysis time and high detection limit. Gas chromatography-mass spectrometry technology has the characteristics of high sensitivity and good selectivity, but in practical applications it faces technical difficulties such as difficulty in waste gas sampling, large matrix interference and low quantitative accuracy. Especially in the high-temperature waste gas sampling process, traditional sampling methods are difficult to effectively enrich the target, resulting in low accuracy of the detection results. At the same time, the existing methods lack a complete quality control system and cannot guarantee the reliability of the analysis results. In addition, production waste gas often contains a variety of interfering substances, such as other aromatic compounds, particulate matter, etc., which will affect the detection sensitivity and accuracy of Naphthol AS-PH.

[0003] The existing analytical methods have insufficient interference suppression ability for complex matrices, and have problems such as poor system stability and high maintenance costs during continuous monitoring. Therefore, it is of great practical significance and application value to establish an efficient analytical method suitable for AS-PH production waste gas. Summary of the invention

[0004] In view of the problems existing in an existing method for detecting waste gas from the production of AS-PH, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is how to establish an efficient, accurate and reliable method for analyzing and determining the AS-PH in the production waste gas.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In the first aspect, an embodiment of the present invention provides a method for detecting waste gas produced by the production of naphthol AS-PH, which includes constructing a pretreatment system combining multi-stage condensation and molecular sieve adsorption, wherein the adsorption unit in the pretreatment system selectively adsorbs water and various interferences in the waste gas through a temperature gradient condensation device combined with silica gel and a mixed molecular sieve to achieve graded removal of water and various interferences in the waste gas, and obtain pretreated purified gas; based on the purified gas, a two-stage tandem capillary chromatographic column separation system utilizing the polarity difference principle is constructed, the separation degree of complex components is improved by a programmed temperature increase method, and a mass spectrometer is used to selectively scan and qualitatively analyze multiple characteristic fragment ions of naphthol AS-PH, and an internal standard method is used to achieve accurate qualitative and quantitative analysis of naphthol AS-PH; on the basis of the accurate qualitative and quantitative analysis of naphthol AS-PH, a quantitative analysis system using deuterated naphthol as an internal standard is established, and the dual confirmation advantages of the selective ion monitoring mode and the multiple reaction monitoring channel are combined to achieve high-precision quantitative detection through a multi-point calibration curve method, thereby achieving standardized detection of waste gas produced by the production of naphthol AS-PH.

[0008] As a preferred embodiment of the method for detecting waste gas from the production of color phenol AS-PH described in the present invention, the method comprises the following steps: the adsorption unit in the pretreatment system selectively adsorbs water and various interferences in the waste gas through a temperature gradient condensation device combined with silica gel and a mixed molecular sieve to remove water and various interferences in the waste gas; the temperature gradient condensation includes primary condensation and secondary condensation; the primary condensation adopts a spiral fin tube for enhancing heat transfer; the secondary condensation adopts a hydrophilic nano material baffle; the adsorption unit adopts activated silica gel and a double-layer composite structure molecular sieve column; the production waste gas is passed into a primary condensation chamber, and the waste gas is preliminarily cooled by a spiral cooling tube to obtain waste gas after primary condensation; the waste gas after primary condensation is passed into a secondary condensation chamber, and the contact time between the waste gas and the cooling surface is extended by the baffle effect of the baffle, so as to improve the condensation efficiency of water and obtain waste gas after secondary condensation.

[0009] As a preferred embodiment of the method for detecting waste gas from the production of color phenol AS-PH described in the present invention, the method comprises the following steps: adding activated silica gel particles to the waste gas after secondary condensation, removing residual moisture and polar organic matter by physical adsorption of the silica gel particles, and obtaining preliminary purified waste gas; selectively removing phenol-type interfering substances from the preliminary purified waste gas by the synergistic adsorption of a mixed molecular sieve, and obtaining purified waste gas; adjusting the waste gas flow rate through a precision flow control system for the purified waste gas, the flow control system comprising a mass flow controller and a pressure sensor, and maintaining the laminar flow state of the gas flow through the flow control system to obtain a pretreated waste gas sample; performing a quality control check on the pretreated waste gas sample, and determining the interfering substance content before and after pretreatment by online gas chromatography, and using an FID detector for gas chromatography to ensure purification efficiency; using a temperature and humidity sensor and a pressure sensor to monitor the temperature, pressure and relative humidity parameters of the pretreated waste gas sample in real time, performing volume correction according to the standard state gas equation, ensuring the standardization of the gas sample state, and obtaining the pretreated purified gas.

[0010] As a preferred embodiment of the method for detecting waste gas from the production of naphthol AS-PH of the present invention, the purified gas is introduced into a chromatographic separation unit; the chromatographic separation unit adopts an HP-5MS capillary chromatographic column, and the theoretical plate number N is calculated by a column efficiency evaluation formula, which is expressed as:

[0011]

[0012] where t R is the component retention time, W 1 / 2 is the half-peak width of the chromatographic peak, and N is the theoretical plate number, which characterizes the separation efficiency of the chromatographic column; establishing a separation efficiency evaluation system based on the theoretical plate number, including: using the theoretical plate number N as the basic parameter for evaluating the separation efficiency of the chromatographic column, determining the temperature program parameter system, establishing a multi-stage temperature rise control strategy through a heating rate formula, and selecting the temperature values ​​of two adjacent temperature points respectively; determining the corresponding time point, calculating the heating rate, selecting and determining the heating rate and constant temperature point of each stage for multiple times, and realizing the sequential separation of the components; calculating the separation degree of adjacent peaks, expressed as:

[0013]

[0014] Where Rs is the separation, t R2 ,t R1 is the retention time of two adjacent peaks, W1 and W2 are the corresponding chromatographic peak widths; according to the separation of adjacent peaks, combined with the temperature program parameters, the temperature program is optimized through the separation index to ensure that the target obtains baseline separation; the optimal carrier gas flow rate is determined based on the Fan equation, expressed as:

[0015]

[0016] Among them, H is the theoretical plate height; u is the carrier gas linear velocity; A is the eddy diffusion term coefficient; B is the longitudinal diffusion term coefficient; C is the mass transfer resistance term coefficient. The optimal carrier gas flow rate is obtained by solving this equation.

[0017] As a preferred embodiment of the method for detecting waste gas from the production of naphthol AS-PH of the present invention, a flow rate-separation degree response relationship is established based on the optimal carrier gas flow rate according to the combined separation degree data to achieve precise control of the carrier gas parameters; and the retention index is calculated for the separated components, which is expressed as:

[0018]

[0019] Wherein, I is the retention index value, t'R(x) is the corrected retention time of the component to be measured, t'R(n) and t'R(n+1)) are the corrected retention times of normal paraffins adjacent to the component to be measured, and n is the number of carbon atoms; a separation chromatogram is obtained based on the chromatographic separation unit, and a preliminary qualitative identification is performed on the target compound in combination with the retention index; the components after preliminary qualitative identification are received by a tandem mass spectrometer detector, wherein the calculation of the resolution R of the mass spectrometer detector is expressed as follows:

[0020]

[0021] Wherein, M is the measured mass, and ΔM is the mass difference between adjacent mass peaks. The components received by the tandem mass spectrometer detector are ionized by electron bombardment to generate characteristic fragment ions, which are used to establish a mass spectral fingerprint. The mass spectral fingerprint contains the mass-to-charge ratio and relative abundance information of the ion fragments. The mass spectral data are extracted based on the obtained mass spectral fingerprint, and the compound is confirmed by the ion ratio β. The ion ratio is expressed as:

[0022]

[0023] Among them, β is the ion ratio, which is used to evaluate the consistency of the characteristic ion intensity ratio between the sample and the standard. m1 is the ionic intensity of the first characteristic ion, I m2 is the ion intensity of the second characteristic ion, sample represents the ion intensity ratio measured in the sample, and std represents the ion intensity ratio measured in the standard. The target is confirmed by the characteristic ion ratio, and the internal standard method is further used for quantitative analysis to establish the response factor F, which is expressed as:

[0024]

[0025] Where F is the response factor, A s is the chromatographic peak area of ​​the analyte, A i is the chromatographic peak area of ​​the internal standard, C i is the internal standard concentration, Cs is the analyte concentration.

[0026] As a preferred embodiment of the method for detecting waste gas from the production of naphthol AS-PH of the present invention, the method comprises the following steps: preparing a deuterated naphthol internal standard stock solution based on the quantitative analysis of the internal standard method, and establishing a response factor system; adding the internal standard working solution to the sample solution to be tested at a ratio of 1:100, vortexing and oscillating to fully mix the solution, and obtaining a sample solution to be tested containing the internal standard; collecting m / z 94 ion fragments and m / z 94→65 transition signals according to the characteristic ion ratio confirmation method, and calculating the characteristic ion ratio, which is expressed as:

[0027]

[0028] Where: I 94 is the signal intensity of the m / z 94 ion, I 65 is the signal intensity of the m / z 65 ion; prepare a standard series of 6 concentration points, repeat the measurement 3 times at each concentration point, calculate the response factor of each point, and verify the linear correlation coefficient; select three concentration levels, measure each concentration 6 times in parallel, and calculate the relative standard deviation RSD, which is expressed as:

[0029]

[0030] Among them, RSD stands for relative standard deviation, which is used to characterize the degree of dispersion of the measurement results; s stands for standard deviation, which reflects the degree of deviation between the measured value and the average value. represents the arithmetic mean, x i represents the i-th measurement value, and n represents the number of measurements. A known concentration of phenol AS-PH standard was added to the blank matrix, and a spike recovery test was performed. Each concentration level was repeated 6 times, and the recovery rate was calculated. The response factor values ​​of the standard solution and the matrix spiked solution were compared, and the matrix effect ME was calculated to ensure that the matrix effect was acceptable.

[0031] As a preferred embodiment of the method for detecting waste gas from the production of naphthol AS-PH of the present invention, the method comprises the following steps: in the standardized detection, it is necessary to ensure that each batch of waste gas samples contains a sampling medium blank, a naphthol AS-PH calibration verification sample, a sampling medium spiked sample, and a parallel sampling double sample; if the relative deviation of the calibration verification sample meets the limit requirement, the precision of the parallel samples meets the requirement, and the detection limit of the blank sample meets the requirement, it indicates that the waste gas sampling and analysis data are reliable; if the quality control result exceeds the limit, the status of the chromatographic instrument is checked, the naphthol AS-PH standard curve is re-prepared, and the batch of waste gas samples is re-analyzed; if the sample is abnormal, check whether the sampling tube is damaged, whether the storage conditions of the sampling tube are appropriate, whether the transportation process meets the requirements, and whether the sample pretreatment process is standardized; if the on-site sampling conditions change, record the abnormal situation, adjust the sampling parameters, and increase the sampling frequency.

[0032] In a second aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, any step of the above-mentioned method for detecting waste gas from the production of phenol AS-PH is implemented.

[0033] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned method for detecting waste gas from the production of phenol AS-PH is implemented.

[0034] The beneficial effects of the present invention are as follows: the waste gas pretreatment system of the present invention, which combines multi-stage condensation cooling with molecular sieve adsorption, can effectively reduce the waste gas temperature and enrich the target substance, thereby significantly improving the sample collection efficiency; combined with the high sensitivity and selectivity of gas chromatography-mass spectrometry technology, accurate qualitative and quantitative analysis of phenol AS-PH is achieved; the internal standard method is used for quantitative analysis, which effectively eliminates the influence of matrix effect and instrument response drift, making the measurement result more reliable; the method is easy to operate and has a fast analysis speed, meets the actual detection needs of phenol AS-PH in production waste gas, and provides reliable technical support for waste gas treatment and environmental monitoring of related enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0036] Figure 1 The present invention is a flow chart of a method for detecting waste gas from the production of AS-PH. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0040] Example 1

[0041] Reference Figure 1 , which is the first embodiment of the present invention, provides a method for detecting waste gas from the production of naphthol AS-PH, comprising:

[0042] S1: Construct a pretreatment system combining multi-stage condensation and molecular sieve adsorption. Through the temperature gradient condensation device combined with silica gel and mixed molecular sieve selective adsorption, the graded removal of moisture and various interferences in the exhaust gas is achieved. The condensation device includes primary condensation and secondary condensation. The primary condensation adopts spiral fin tubes for enhanced heat transfer, and the secondary condensation adopts hydrophilic nanomaterial baffles. The adsorption unit adopts activated silica gel and double-layer composite structure molecular sieve column.

[0043] The production waste gas is passed into the primary condensation chamber, and the temperature of the primary condensation chamber is set to 10-15°C. A spiral cooling tube with an enhanced heat transfer structure is arranged in the primary condensation chamber. The spiral cooling tube is made of stainless steel with a surface sandblasting treatment, and the tube wall thickness is 2.5-3.0mm. The pitch of the spiral coil is 15-20mm. A fin structure is arranged on the inner wall of the coil. The height of the fin is 2-3mm, and the fin spacing is 8-10mm. The waste gas is initially cooled by the spiral cooling tube to obtain the waste gas after primary condensation.

[0044] The exhaust gas after the primary condensation is passed into the secondary condensation chamber. The temperature of the secondary condensation chamber is 5-8°C. A multi-layer baffle is arranged in the secondary condensation chamber. The baffle is made of hydrophilic material. The surface of the baffle is coated with hydrophilic nanomaterial. The particle size of the nanomaterial is 50-100nm and the coverage density is 200-300g / m 2 , through the baffle effect of the baffle plate, the contact time between the exhaust gas and the cooling surface is extended, the condensation efficiency of the water is improved, the secondary condensation efficiency is controlled to reach more than 95%, and the exhaust gas after secondary condensation is obtained;

[0045] Activated silica gel particles are added to the waste gas after secondary condensation. The particle size of the silica gel particles is 80-120 mesh. The silica gel particles are used after being activated at 400°C for 4 hours. The mass ratio of silica gel particles to waste gas is 1:50. Adsorption is carried out in a glass adsorption column. The inner diameter of the glass adsorption column is 30mm and the length is 200mm. The inner wall of the adsorption column is hydrophobic. The adsorption time is controlled at 3-5min. The residual moisture and polar organic matter are removed by the physical adsorption of silica gel particles to obtain preliminary purified waste gas.

[0046] The preliminarily purified waste gas is passed through a molecular sieve adsorption column, which is filled with a mixture of 4A type molecular sieve and 5A type molecular sieve in a mass ratio of 3:1. The molecular sieve is activated at 450°C for 6 hours before use. The molecular sieve adsorption column adopts a double-layer structure design, with an inner layer of 316L stainless steel wire mesh and an outer layer of quartz glass. The working temperature of the adsorption column is controlled at 25-30°C. Phenol interferences are selectively removed through the synergistic adsorption of the mixed molecular sieves, and the adsorption capacity is not less than 0.3g / g to obtain purified waste gas;

[0047] The 4A molecular sieve has a pore size of 0.4nm and exhibits excellent adsorption selectivity for small molecule water and polar organic matter; the 5A molecular sieve has a pore size of 0.5nm and has a strong adsorption capacity for medium molecular weight phenol compounds. After the two molecular sieves are mixed in a mass ratio of 3:1, a gradient adsorption layer is formed through the combination of different pore sizes. The 4A molecular sieve preferentially removes small molecule interfering substances, providing a purer gas phase environment for the 5A molecular sieve to selectively adsorb the target.

[0048] The waste gas flow rate is adjusted by a precision flow control system for the purified waste gas. The flow control system includes a mass flow controller and a pressure sensor to control the waste gas flow rate within the range of 400-600 mL / min. The response time of the control system is less than 100 ms, and the control accuracy is ±1%. The gas pipeline is made of 316L stainless steel with a polished inner wall and an inner diameter of 8 mm. The laminar flow state of the gas flow is maintained by the flow control system to obtain the pretreated waste gas sample.

[0049] The waste gas samples after pretreatment were subjected to quality control inspection, and the interfering substance content before and after pretreatment was determined by online gas chromatography. The gas chromatography used an FID detector, an injection volume of 1 mL, a control temperature of 180°C, and a carrier gas of high-purity nitrogen. The removal rate of interfering substances before and after pretreatment was calculated to ensure that the purification efficiency was not less than 98%.

[0050] Temperature and humidity sensors and pressure sensors are used to monitor the temperature, pressure and relative humidity parameters of the pretreated exhaust gas samples in real time. The temperature is controlled at 25±0.5℃, the pressure is controlled at 101.3±0.5kPa, and the relative humidity is controlled below 30%. Volume correction is performed according to the standard state gas equation to ensure the standardization of the gas sample state.

[0051] S2: Based on the pretreated purified gas, a two-stage tandem capillary column separation system was constructed using the principle of polarity difference. The separation degree of complex components was improved by programmed temperature increase, and a mass spectrometer was used to selectively scan and qualitatively analyze multiple characteristic fragment ions of AS-PH. The internal standard method was used to achieve accurate qualitative and quantitative analysis of AS-PH.

[0052] The purified gas sample after pretreatment is introduced into the chromatographic separation unit. The chromatographic separation unit uses an HP-5MS capillary column. The theoretical plate number N is calculated by the column efficiency evaluation formula, which is expressed as:

[0053]

[0054] where t R is the component retention time, W 1 / 2 is the half-peak width of the chromatographic peak, and N is the number of theoretical plates, which characterizes the separation efficiency of the chromatographic column.

[0055] The separation program is adjusted according to the theoretical plate number N to control the component separation efficiency. The separation program is temperature controlled by programmed heating to ensure that the sample components are baseline separated.

[0056] Furthermore, a separation efficiency evaluation system based on the number of theoretical plates is established, including:

[0057] The theoretical plate number N is used as the basic parameter for evaluating the separation efficiency of the chromatographic column, the temperature program parameter system is determined, and a multi-stage temperature rise control strategy is established through the heating rate formula. The temperature values ​​of two adjacent temperature points are selected respectively; the corresponding time points are determined, the heating rate is calculated, and the heating rate and constant temperature point of each stage are determined by multiple selections to achieve sequential separation of components.

[0058] Calculate the separation of adjacent peaks, expressed as:

[0059]

[0060] Where Rs is the separation, t R2 ,t R1 is the retention time of two adjacent peaks, W1 and W2 are the corresponding chromatographic peak widths.

[0061] According to the separation of adjacent peaks and the temperature program parameters, the temperature program is optimized through the separation index to ensure that the target objects are baseline separated.

[0062] The optimal carrier gas flow rate is determined based on the Fan equation, which is expressed as:

[0063]

[0064] Among them, H is the theoretical plate height; u is the carrier gas linear velocity; A is the eddy diffusion term coefficient; B is the longitudinal diffusion term coefficient; C is the mass transfer resistance term coefficient. The optimal carrier gas flow rate is obtained by solving this equation.

[0065] According to the optimal carrier gas flow rate and the combined separation data, a flow rate-separation degree response relationship is established to achieve precise control of the carrier gas parameters.

[0066] The retention index is calculated for the separated components and is expressed as:

[0067]

[0068] Wherein, I is the retention index value, t'R(x) is the corrected retention time of the component to be measured, t'R(n) and t'R(n+1)) are the corrected retention times of normal paraffins adjacent to the component to be measured, and n is the number of carbon atoms.

[0069] The separation chromatogram is obtained based on the chromatographic separation unit, and the target compound is preliminarily qualitatively identified in combination with the retention index.

[0070] The components after preliminary qualitative identification are received by a tandem mass spectrometer detector, wherein the calculation of the resolution R of the mass spectrometer detector is expressed as:

[0071]

[0072] Where M is the measured mass and ΔM is the mass difference between adjacent mass peaks.

[0073] The components received by the tandem mass spectrometer are ionized by electron bombardment to produce characteristic fragment ions. The characteristic fragment ions are used to establish a mass spectral fingerprint. The mass spectral fingerprint contains the mass-to-charge ratio and relative abundance information of the ion fragments.

[0074] The mass spectrometry data was extracted based on the mass spectrometry fingerprint, and the compound was confirmed by the ion ratio β. The ion ratio is expressed as:

[0075]

[0076] Among them, β is the ion ratio, which is used to evaluate the consistency of the characteristic ion intensity ratio between the sample and the standard. m1 is the ionic intensity of the first characteristic ion, I m2is the ion intensity of the second characteristic ion, sample represents the ion intensity ratio measured in the sample, and std represents the ion intensity ratio measured in the standard.

[0077] The target compound was confirmed by the characteristic ion ratio, and the internal standard method was further used for quantitative analysis to establish the response factor F, which is expressed as:

[0078]

[0079] Where F is the response factor, A s is the chromatographic peak area of ​​the analyte, A i is the chromatographic peak area of ​​the internal standard, C i is the internal standard concentration, C s is the analyte concentration.

[0080] The working curve is established by the response factor F. The response factor F reflects the relative response sensitivity of the analyte and the internal standard, and its stability directly affects the reliability of the quantitative results. The linear range and correlation coefficient of the working curve provide basic data for method evaluation.

[0081] A multiple linear regression correction model was established. Based on the response factor data, the mathematical relationship between the response value and multiple influencing factors was established. The model considered the comprehensive influence of factors such as carrier gas flow rate, column temperature, injection volume, etc. on the determination results, and quantified the contribution of each factor through regression analysis. The multiple linear regression correction model is expressed as:

[0082]

[0083] Among them, y is the response value, x is i is the influencing factor, b i is the regression coefficient of the i-th influencing factor, b0 means when all influencing factors x i The baseline response value when all are 0, and n is the total number of influencing factors.

[0084] The multiple linear regression calibration model was estimated using standard errors, expressed as:

[0085]

[0086] Among them, y i is the measured value, is the theoretical response value calculated by the multiple linear regression correction model, n is the sample size, and SE represents the standard error.

[0087] The standard error SE reflects the goodness of fit of the model and provides a quantitative basis for method optimization.

[0088] S3: On the basis of achieving accurate separation and qualitative identification of the target, a quantitative analysis system with deuterated chromatin as the internal standard is established. Combining the dual confirmation advantages of the selective ion monitoring mode and the multiple reaction monitoring channel, high-precision quantitative detection is achieved through the multi-point calibration curve method, and a complete data quality assurance system is established.

[0089] Based on the internal standard method for quantitative analysis, a deuterated hydroxyphenol internal standard stock solution was prepared: 100 mg (accurate to 0.1 mg) of deuterated hydroxyphenol standard was weighed, dissolved in methanol and diluted to 100 mL to prepare a 1000 mg / L stock solution; 1 mL of the stock solution was taken, diluted to 100 mL with methanol to obtain a 10 mg / L working solution for establishing a response factor system.

[0090] The internal standard working solution was added to the sample solution at a ratio of 1:100, and vortexed for 30 seconds to fully mix the solution to obtain the sample solution containing the internal standard.

[0091] According to the characteristic ion ratio confirmation method, the m / z 94 ion fragment and the m / z 94→65 transition signal were collected, the ion source temperature was maintained at 280°C, the ionization energy was 70 eV, and the dwell time was 100 ms. The characteristic ion ratio was calculated and expressed as:

[0092]

[0093] Where: I 94 is the signal intensity of the m / z 94 ion, I 65 is the m / z 65 ion signal intensity.

[0094] The response factor F was calculated to characterize the relative response relationship between the analyte and the internal standard.

[0095] Prepare a standard series of 6 concentration points (0.01, 0.05, 0.1, 1.0, 5.0, 10.0 mg / L), and repeat the measurement 3 times at each concentration point. right Draw a graph, calculate the response factor of each point, and verify the linear correlation coefficient R 2 ≥0.995.

[0096] Select three concentration levels of 0.1, 1.0, and 5.0 mg / L, measure each concentration 6 times in parallel, and calculate the relative standard deviation RSD, which is expressed as:

[0097]

[0098] Among them, RSD stands for relative standard deviation, which is used to characterize the degree of dispersion of the measurement results; s stands for standard deviation, which reflects the degree of deviation between the measured value and the average value. represents the arithmetic mean, x irepresents the i-th measurement value, and n represents the number of measurements.

[0099] During the determination process, RSD was ensured to be ≤15%, that is, the relative standard deviation of the results of 6 repeated measurements should not be greater than 15% to ensure that the precision of the method met the requirements.

[0100] A known concentration of naphthoic acid AS-PH standard (0.1, 1.0, 5.0 mg / L) was added to the blank matrix, and the spike recovery test was performed. Each concentration level was repeated 6 times, and the recovery rate was calculated to ensure that the recovery rate range remained between 85% and 115%.

[0101] The response factor F values ​​of the standard solution and the matrix-spiked solution were compared, and the matrix effect ME was calculated. When ME was in the range of 80% to 120%, the matrix effect was considered acceptable.

[0102] During the testing process, it is necessary to ensure that each batch of exhaust gas samples contains a sampling medium blank, a 1.0 mg / L phenol AS-PH calibration verification sample, a sampling medium spiked sample, and parallel sampling duplicate samples.

[0103] If the relative deviation between the calibration verification sample measurement result and the theoretical value is ≤±15%, the relative deviation of the parallel sample is ≤15%, and the sampling medium spike recovery rate is 85% to 115%, then the exhaust gas sampling analysis data is reliable.

[0104] If the theoretical plate number of the chromatographic peak of Naphthophenol AS-PH is ≥3000, the tailing factor of the peak of Naphthophenol AS-PH is ≤1.5, and the retention time deviation of Naphthophenol AS-PH is ≤0.2min, it indicates that the analysis is in good condition.

[0105] If the quality control result exceeds the limit, check the status of the chromatographic instrument, re-prepare the chromatographic phenol AS-PH standard curve, re-analyze the batch of waste gas samples, and re-sample if necessary.

[0106] If the sample is abnormal, check whether the sampling tube is damaged, check whether the storage conditions of the sampling tube are appropriate, check whether the transportation process meets the requirements, and check whether the sample pre-treatment process is standardized.

[0107] If the on-site sampling conditions change, record the abnormal situation, adjust the sampling parameters, increase the sampling frequency, and add sampling points if necessary.

[0108] This embodiment also provides a computer device, which is suitable for a method for detecting waste gas from the production of phenol AS-PH, and includes a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement a method for detecting waste gas from the production of phenol AS-PH as proposed in the above embodiment.

[0109] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0110] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, a method for detecting waste gas from the production of AS-PH phenol is implemented as proposed in the above embodiment.

[0111] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0112] Example 2

[0113] This embodiment provides a method for detecting waste gas from the production of naphthol AS-PH. In order to verify the beneficial effects of the present invention, a scientific demonstration is carried out through simulation experiments.

[0114] In order to verify the advantages of the present invention, the method of the present invention and the traditional liquid chromatography method were used to measure the same batch of waste gas samples of naphthophenol AS-PH production. The experimental process includes:

[0115] Accurately weigh 100 mg of Naphthol AS-PH standard and dilute to 100 mL with methanol to prepare a 1000 mg / L stock solution;

[0116] Use the stock solution to dilute in stages to prepare standard working solutions of 0.05, 0.1, 0.5, 1.0, 5.0, 10.0, 50.0, and 100.0 mg / L;

[0117] Weigh 50 mg of deuterated naphthalene and dilute to 50 mL with methanol to prepare a 1000 mg / L internal standard stock solution.

[0118] Use 13X molecular sieve with a filling amount of 50 g, maintain the activation temperature at 350°C for 4 hours, and use N2 gas for detection at a flow rate of 2 L / min to ensure no leakage.

[0119] Collect exhaust gas samples, record environmental parameters such as temperature, pressure, and humidity at the sampling point, sample continuously for 30 minutes, record the flow rate every 10 minutes, collect 6 parallel samples, and collect blank samples on site at the same time.

[0120] According to the collected samples, the method of the present invention and the traditional liquid chromatography method were used for detection respectively. The experimental results show that the detection limit of the method of the present invention is 1 / 10 of that of the traditional method, and the linear range is wider, indicating that the method has higher detection sensitivity and a wider range of application.

[0121] The recovery rate of the method of the present invention reaches 98.5%, which is much higher than that of the traditional method, and under such circumstances, the relative standard deviation is only 2.8%, which is better than 6.5% of the traditional method.

[0122] The 24-hour stability change of the sample of the present invention is less than 2%, while the change of the traditional method is 8%. The uncertainty of the method of the present invention is significantly lower than 7.5% of the traditional method, and has a strong ability to resist matrix interference.

[0123] Through experimental analysis, it is verified that the method of the present invention is significantly superior to the traditional liquid chromatography method, and provides a reliable technical support for the rapid and accurate detection of waste gas from the production of AS-PH.

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for detecting waste gas from the production of naphthol AS-PH, characterized in that: include: Construct a pretreatment system combining multi-stage condensation and molecular sieve adsorption, in which the adsorption unit in the pretreatment system selectively adsorbs by combining a temperature gradient condensation device with silica gel and a mixed molecular sieve to achieve graded removal of moisture and various interferences in the exhaust gas, and obtain pretreated purified gas; Based on the purified gas, a two-stage tandem capillary chromatographic column separation system using the polarity difference principle is constructed, the separation degree of complex components is improved by a programmed temperature method, and a mass spectrometer is used to selectively scan and qualitatively analyze multiple characteristic fragment ions of naphthophenol AS-PH, and an internal standard method is used to achieve accurate qualitative and quantitative analysis of naphthophenol AS-PH; On the basis of the accurate qualitative and quantitative analysis of the naphthol AS-PH, a quantitative analysis system with deuterated naphthol as the internal standard was established. Combining the dual confirmation advantages of the selective ion monitoring mode and the multiple reaction monitoring channel, high-precision quantitative detection was achieved through the multi-point calibration curve method, thereby realizing the standardized detection of naphthol AS-PH production waste gas.

2. The method for detecting waste gas from the production of Naphthol AS-PH as claimed in claim 1, characterized in that: The adsorption unit in the pretreatment system removes moisture and various interferences from the exhaust gas through selective adsorption by combining a temperature gradient condensation device with silica gel and a mixed molecular sieve; The temperature gradient condensation includes primary condensation and secondary condensation; The first-stage condensation adopts spiral finned tubes for enhanced heat transfer; The secondary condensation adopts a hydrophilic nano material baffle; The adsorption unit uses activated silica gel and a double-layer composite structure molecular sieve column; The production waste gas is passed into the primary condensation chamber, and the waste gas is initially cooled by a spiral cooling tube to obtain the waste gas after primary condensation; The exhaust gas after primary condensation is passed into the secondary condensation chamber, and the contact time between the exhaust gas and the cooling surface is prolonged through the baffle effect of the baffle plate, thereby improving the condensation efficiency of water and obtaining the exhaust gas after secondary condensation.

3. The method for detecting waste gas from the production of Naphthol AS-PH as claimed in claim 2, characterized in that: Activated silica gel particles are added to the waste gas after secondary condensation, and residual moisture and polar organic matter are removed through the physical adsorption of silica gel particles to obtain preliminary purified waste gas; The preliminarily purified waste gas is selectively removed of phenolic interfering substances through the synergistic adsorption of the mixed molecular sieve to obtain purified waste gas; The purified waste gas is passed through a precision flow control system to adjust the waste gas flow rate, the flow control system includes a mass flow controller and a pressure sensor, and the laminar flow state of the gas flow is maintained through the flow control system to obtain a pretreated waste gas sample; Conduct quality control checks on pre-treated waste gas samples, and use online gas chromatography to determine the content of interfering substances before and after pretreatment. The gas chromatography uses a FID detector to ensure purification efficiency; Temperature and humidity sensors and pressure sensors are used to monitor the temperature, pressure and relative humidity parameters of the pretreated exhaust gas samples in real time. Volume correction is performed according to the standard state gas equation to ensure the standardization of the gas sample state and obtain the pretreated purified gas.

4. The method for detecting waste gas from the production of Naphthol AS-PH as claimed in claim 3, characterized in that: Based on the purified gas being introduced into a chromatographic separation unit; The chromatographic separation unit uses an HP-5MS capillary chromatographic column, and the theoretical plate number N is calculated by the column efficiency evaluation formula, which is expressed as: where t R is the component retention time, W 1 / 2 is the half-peak width of the chromatographic peak, and N is the number of theoretical plates, which characterizes the separation efficiency of the chromatographic column; Establish a separation efficiency evaluation system based on the number of theoretical plates, including: The theoretical plate number N is used as the basic parameter for evaluating the separation efficiency of the chromatographic column, the temperature program parameter system is determined, a multi-stage temperature rise control strategy is established through a heating rate formula, and the temperature values ​​of two adjacent temperature points are selected respectively; the corresponding time points are determined, the heating rate is calculated, and the heating rate and constant temperature point of each stage are selected multiple times to achieve sequential separation of components; Calculate the separation of adjacent peaks, expressed as: Where Rs is the separation, t R2 ,t R1 is the retention time of two adjacent peaks, W1 and W2 are the corresponding chromatographic peak widths; According to the separation of adjacent peaks and the temperature program parameters, the temperature program is optimized through the separation index to ensure that the target is baseline separated; The optimal carrier gas flow rate is determined based on the Fan equation, which is expressed as: Among them, H is the theoretical plate height; u is the carrier gas linear velocity; A is the eddy diffusion term coefficient; B is the longitudinal diffusion term coefficient; C is the mass transfer resistance term coefficient. The optimal carrier gas flow rate is obtained by solving this equation.

5. The method for detecting waste gas from the production of Naphthol AS-PH as claimed in claim 4, characterized in that: Based on the optimal carrier gas flow rate, a flow rate-separation degree response relationship is established according to the combined separation degree data to achieve precise control of carrier gas parameters; The retention index is calculated for the separated components and is expressed as: Wherein, I is the retention index value, t'R(x) is the corrected retention time of the component to be measured, t'R(n) and t'R(n+1)) are the corrected retention times of n-paraffins adjacent to the component to be measured, and n is the number of carbon atoms; Based on the chromatographic separation unit, the separation chromatogram is obtained, and the target compound is preliminarily qualitatively identified in combination with the retention index; The components after preliminary qualitative identification are received by a tandem mass spectrometer detector, wherein the calculation of the resolution R of the mass spectrometer detector is expressed as: Where M is the measured mass, and ΔM is the mass difference between adjacent mass peaks; The components received by the tandem mass spectrometer are ionized by electron bombardment to generate characteristic fragment ions, and the characteristic fragment ions are used to establish a mass spectrum fingerprint, which contains the mass-to-charge ratio and relative abundance information of the ion fragments; The mass spectrometry data was extracted based on the mass spectrometry fingerprint, and the compound was confirmed by the ion ratio β. The ion ratio is expressed as: Among them, β is the ion ratio, which is used to evaluate the consistency of the characteristic ion intensity ratio between the sample and the standard. m1 is the ionic intensity of the first characteristic ion, I m2 is the ion intensity of the second characteristic ion, sample represents the ion intensity ratio measured in the sample, and std represents the ion intensity ratio measured in the standard; The target compound was confirmed by the characteristic ion ratio, and the internal standard method was further used for quantitative analysis to establish the response factor F, which is expressed as: Where F is the response factor, A s is the chromatographic peak area of ​​the analyte, A i is the chromatographic peak area of ​​the internal standard, C i is the internal standard concentration, C s is the analyte concentration.

6. The method for detecting waste gas from the production of Naphthol AS-PH as claimed in claim 5, characterized in that: Based on the quantitative analysis of the internal standard method, a deuterated chromatin internal standard stock solution is prepared, and a response factor system is established; The internal standard working solution was added to the sample solution at a ratio of 1:100, and vortexed to mix thoroughly to obtain the sample solution containing the internal standard; According to the characteristic ion ratio confirmation method, the m / z 94 ion fragment and the m / z 94→65 transition signal were collected, and the characteristic ion ratio was calculated, which is expressed as: Where: I 94 is the signal intensity of the m / z 94 ion, I 65 is the m / z 65 ion signal intensity; Prepare a standard series of 6 concentration points, repeat the measurement 3 times at each concentration point, calculate the response factor of each point, and verify the linear correlation coefficient; Three concentration levels were selected, and each concentration was measured 6 times in parallel. The relative standard deviation (RSD) was calculated and expressed as: Among them, RSD stands for relative standard deviation, which is used to characterize the degree of dispersion of the measurement results; s stands for standard deviation, which reflects the degree of deviation between the measured value and the average value. represents the arithmetic mean, x i represents the i-th measurement value, and n represents the number of measurements; A known concentration of Naphthophenol AS-PH standard was added to the blank matrix, and the spike recovery test was performed. Each concentration level was repeated 6 times, and the recovery was calculated; Compare the response factor values ​​of the standard solution and the matrix spiked solution, calculate the matrix effect ME, and ensure that the matrix effect is acceptable.

7. The method for detecting waste gas from the production of Naphthol AS-PH as claimed in claim 6, characterized in that: In the standardized test, it is necessary to ensure that each batch of exhaust gas samples contains a sampling medium blank, a naphthophenol AS-PH calibration verification sample, a sampling medium spiked sample, and a parallel sampling double sample; If the relative deviation of the calibration verification sample meets the limit requirements, the precision of the parallel samples meets the requirements, and the detection limit of the blank sample meets the requirements, it means that the exhaust gas sampling and analysis data are reliable; If the quality control result exceeds the limit, check the status of the chromatographic instrument, re-prepare the AS-PH standard curve of Naphthol, and re-analyze the waste gas samples of the batch; If the sample is abnormal, check whether the sampling tube is damaged, check whether the storage conditions of the sampling tube are appropriate, check whether the transportation process meets the requirements, and check whether the sample pre-treatment process is standardized; If the on-site sampling conditions change, record the abnormal situation, adjust the sampling parameters, and increase the sampling frequency.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a method for detecting waste gas from the production of naphthol AS-PH as described in any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for detecting waste gas from the production of naphthol AS-PH as described in any one of claims 1 to 7 are implemented.

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