A method for preparing a trace 10-component solution standard of endocrine disruptor phenols

Abstract

The application discloses a preparation method of trace 10-component phenolic endocrine disruptor solution standard substance, which comprises the following steps: accurately weighing 10 kinds of high-purity phenolic compounds with accurate values, and dissolving the phenolic compounds in a mass spectrometry grade methanol solvent in a nitrogen atmosphere operation box to obtain a dissolved phenolic standard; filling nitrogen into a volumetric flask, pouring the dissolved phenolic standard into the volumetric flask, and dissolving and constant volume of the dissolved phenolic standard in a constant-temperature tank at 20.0 DEG C + / - 0.5 DEG C for 20 min, and then using the mass spectrometry grade methanol solvent to dissolve and constant volume to obtain a constant-volume phenolic solution; gradually diluting the constant-volume phenolic solution to 1 ug / L by using the mass spectrometry grade methanol solvent to obtain a diluted phenolic solution; pre-filling argon into a brown glass ampoule in a nitrogen atmosphere operation box, and then pouring the diluted phenolic solution into the brown glass ampoule, filling argon above the ampoule containing the solution, and fusion sealing the ampoule for refrigeration preservation.

Description

Technical Field

[0001] This invention relates to the field of standard substance preparation, and in particular to a method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance. Background Technology

[0002] Phenolic endocrine disrupting chemicals (PEDCs) are a class of organic compounds with estrogen-like activity, widely found in industrial wastewater, domestic sewage, agricultural runoff, and food contact materials. Currently, approximately 6070 chemical substances worldwide have been identified as having endocrine-disrupting properties, but standardized detection methods and matrix reference materials for multi-component PEDCs remain lacking. Traditional single-component detection methods are inefficient and costly, failing to meet the need for simultaneous analysis of trace pollutants in complex environmental samples. Most commercially available reference materials only target a few phenolic substances, making it difficult to simultaneously detect trace amounts of 10 phenolic endocrine disrupting chemicals.

[0003] Therefore, there is an urgent need to develop a trace 10-component phenolic endocrine disruptor solution standard material to improve the technical level of phenolic endocrine disruptor detection and research, meet market and regulatory needs, and provide strong technical support for environmental monitoring, food safety assurance, public health promotion and ecological environmental protection. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a trace 10-component phenolic endocrine disruptor solution standard.

[0005] To achieve the above objectives, the present invention is implemented according to the following technical solution: This invention includes the following steps: S1. Accurately weigh 10 high-purity phenolic compounds with accurately determined purity values, dissolve them in a nitrogen-atmospheric atmosphere using mass spectrometry-grade methanol solvent, and obtain dissolved phenolic standards; the mass spectrometry-grade methanol solvent contains 0.05% butylated hydroxytoluene + 0.1% formic acid + 0.01% EDTA; the mass spectrometry-grade methanol solvent is obtained through a combined stabilizer preparation experiment; S2. Fill the volumetric flask with nitrogen gas, pour the dissolved phenolic standard into the volumetric flask, keep it at a constant temperature of 20.0℃±0.5℃ for 20 min in a constant temperature bath, and then dissolve and dilute the solution with the mass spectrometry grade methanol solvent to obtain a diluted phenolic solution. S3. The phenolic solution is gradually diluted to 1 μg / L using the mass spectrometry-grade methanol solvent to obtain a diluted phenolic solution; S4. In a nitrogen atmosphere operating chamber, the brown glass ampoules are pre-filled with argon gas. The diluted phenolic solution is then dispensed into the brown glass ampoules. Argon gas is then introduced above the ampoules containing the solution to seal the ampoules and store them frozen.

[0006] Furthermore, the method for pre-treating the raw materials of the high-purity phenolic compounds includes: Take out the high-purity phenolic compound raw material stored at room temperature, protected from light, and in a dry place, and equilibrate it in a P2O5 desiccator for 48 hours after accurate purity determination. Place a clean weighing boat on an electronic balance. Once the balance is stable, tare the balance and zero it. Use a weighing spoon to quantitatively transfer 100 mg of raw material into the weighing boat. Once the balance is stable, read the value. Transfer the weighed raw material to a 1 L brown volumetric flask. Rinse the weighing boat several times with solvent, and transfer all the washing solution to the volumetric flask. The 1 L brown volumetric flask is pre-filled with argon gas. The weighing and transfer of raw material are carried out in an operating box under a saturated nitrogen atmosphere.

[0007] Further, the method for preparing the combined stabilizer is as follows: accurately weigh 0.5 g of butylated hydroxytoluene and transfer it to a 1 L volumetric flask, rinse with mass spectrometry-grade methanol, and completely transfer it to the volumetric flask; accurately weigh 1 g of formic acid and transfer it to the above volumetric flask, rinse with mass spectrometry-grade methanol, and completely transfer it to the volumetric flask; then accurately weigh 0.1 g of EDTA and transfer it to the above volumetric flask, rinse with mass spectrometry-grade methanol, and completely transfer it to the volumetric flask.

[0008] Further, a type 1 mass spectrometry grade methanol solvent is added to S1 to about 2 / 3 of the volumetric flask volume, and gently shaken until completely dissolved.

[0009] Furthermore, the volume-degrading method includes: Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the graduation mark, then stop. Stop the flask and place it in a 20°C constant temperature bath for 30 min. After bringing the volume to the mark, bring it to the mark again and hold it at the temperature for 30 min to confirm that the volume has been brought to the graduation mark. Ensure that the components are evenly distributed. The volumetric solution for phenol needs to be vortexed for 10 seconds and sonicated in an ice bath for 5 seconds, repeated 3 times. The sonication in the ice bath should be at 40 kHz.

[0010] Further, the dilution method includes: Accurately transfer 10 mL of the phenolic solution to a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the mark. Stop adding the flask and place it in a 20℃ constant temperature bath for 30 min. Then, bring the volume to the mark and heat it again for 30 min. Confirm that the volume has been brought to the mark to obtain a first-degree diluted solution. Take 10 mL of the first-stage dilution solution into a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm away from the mark. Stop the flask with the stopper and place it in a 20℃ constant temperature bath for 30 min. Then, dilute to the mark and keep it in the constant temperature bath for another 30 min. Confirm that the volume has been diluted to the mark to obtain the second-stage dilution solution. Take 10 mL of the grade 2 dilution solution into a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the mark. Stop adding the flask and place it in a 20℃ constant temperature bath for 30 min. Then, bring the volume to the mark and heat it again for 30 min. Confirm that the volume has been brought to the mark to obtain the diluted phenol solution.

[0011] Further, the method for pre-treating the brown glass ampoule includes: Pickling, rinsing with ultrapure water, rinsing with methanol, and drying at 120°C; the pickling is performed using 10% HNO3 and soaking for 24 hours; the dried ampoules are treated with 5% dimethyldichlorosilane / toluene solution for 1 hour, rinsed with methanol, and dried at 120°C for later use.

[0012] Furthermore, the 10 phenolic compounds include: 4-tert-butylphenol (CAS: 98-54-4), 4-butylphenol (CAS: 1638-22-8), 4-pentylphenol (CAS: 14938-35-3), 4-hexylphenol (CAS: 2446-69-7), 4-heptylphenol (CAS: 1987-50-4), 4-octylphenol (CAS: 1806-26-4), 4-branched nonylphenol (CAS: 84852-15-3), 4-tert-octylphenol (CAS: 140-66-9), 4-nonylphenol (CAS: 104-40-5), and bisphenol A (CAS: 80-05-7).

[0013] Furthermore, the packaging method includes: A hydrogen-oxygen welding machine was used as the dispensing equipment, and the dispensing gas was a mixture of hydrogen and oxygen. Before dispensing, the diluted phenolic solution to be dispensed was frozen at -10℃ for 24 hours. After thoroughly mixing the diluted phenolic solution, the diluted phenolic solution to be dispensed in the volumetric flask was poured into a glass storage bottle, sealed with a cap with a switch valve, and then injected into 2mL brown glass ampoules using a syringe with a switch valve. The dispensing volume was 1mL, and the ampoules were stored frozen at (-10±5)℃ in the dark.

[0014] Furthermore, for the brown glass ampoules, a cooling sleeve is placed on the neck and below the neck of the ampoule before dispensing.

[0015] Furthermore, both the dilution and dispensing processes are carried out in an operating chamber under a saturated nitrogen atmosphere.

[0016] The beneficial effects of this invention are: This invention provides a method for preparing a trace 10-component phenolic endocrine disruptor solution standard. Compared with existing technologies, this invention has the following technical advantages: This invention can prepare a 10-component phenolic endocrine disruptor solution standard with a concentration of 1 μg / L. By pretreating the ampoules, adding a combined stabilizer, and purging with argon, the prepared 1 μg / L 10-component phenolic endocrine disruptor solution standard can be stably stored for 12 months under light-protected and frozen conditions. The 1 μg / L 10-component phenolic endocrine disruptor solution standard is dispensed, with strict control over the influence of flame temperature and the residue after combustion of the sealing gas on solution stability. The preparation of trace 10-component phenolic endocrine disruptor solution standard exhibits stability, reliability, and strong repeatability. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the steps of a method for preparing a trace 10-component phenolic endocrine disruptor solution standard material according to the present invention. Figure 2 This is a trend graph showing the long-term stability of the trace 10-component phenolic endocrine disruptor solution standard material with different stabilizers added in the examples of this specification. Detailed Implementation

[0018] The present invention will be further described below through specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0019] The present invention provides a method for preparing a trace 10-component phenolic endocrine disruptor solution standard, comprising the following steps: like Figure 1 As shown, this embodiment includes the following steps: S1. Accurately weigh 10 high-purity phenolic compounds with accurately determined purity values, dissolve them in a nitrogen-atmospheric atmosphere using mass spectrometry-grade methanol solvent to obtain dissolved phenolic standards; the mass spectrometry-grade methanol solvent is 0.05% butylated hydroxytoluene + 0.1% formic acid + 0.01% EDTA; the mass spectrometry-grade methanol solvent is obtained through a combined stabilizer preparation experiment; S2. Fill the volumetric flask with nitrogen gas, pour the dissolved phenolic standard into the volumetric flask, keep it at a constant temperature of 20.0℃±0.5℃ for 20 min in a constant temperature bath, and then dissolve and dilute the solution with the mass spectrometry grade methanol solvent to obtain a diluted phenolic solution. S3. The phenolic solution is gradually diluted to 1 μg / L using the mass spectrometry-grade methanol solvent to obtain a diluted phenolic solution; S4. In a nitrogen atmosphere operating chamber, the brown glass ampoules are filled with argon gas beforehand. The diluted phenolic solution is then dispensed into the brown glass ampoules. Argon gas is then filled above the ampoules containing the solution to seal the ampoules and store them frozen. In the actual evaluation, a long-term stability study was conducted on a 1.00 μg / L trace 10-component phenolic endocrine disruptor solution standard. Over a 12-month period, following a principle of starting with closer intervals and gradually decreasing them, the instrument operating conditions were strictly controlled for each test of the trace 10-component phenolic endocrine disruptor solution standard stored under refrigeration conditions to minimize the impact on instrument reproducibility. Three bottles were randomly selected each time, and each bottle was measured three times. The average of the three measurements was taken as the result for one bottle, and the average of the three measurements was taken as the final measurement result. According to the standard JJF1343-2012 "General Principles and Statistical Principles for Standard Reference Material Value Determination", a linear fit was performed on the molar concentration c versus time T based on the stability study results. If... This indicates that the slope of the straight line in the solution stability test result is not significant, and the standard substance has good stability. If This indicates that the slope of the straight line in the solution stability test is significant, suggesting poor stability of the standard substance. The test results are shown in Table 10. Table 1. Results of long-term stability study of trace 10-component phenolic endocrine disruptor solution standard substances Experimental results demonstrate that this method for preparing trace 10-component phenolic endocrine disruptor solution standards is stable, reliable, and highly reproducible. The solution standards exhibit accurate and stable values ​​under both refrigerated transport conditions and 12-month long-term storage, making them suitable for measurement, calibration, quality control, proficiency testing, and method validation of total organic carbon in solutions. To ensure the comparability of trace 10-component phenolic endocrine disruptor solution standards in solutions from different regions and at different times, and to guarantee the traceability of measurement results, this method provides accurate, homogeneous, and stable solution standards for the detection of trace 10-component phenolic endocrine disruptor solutions.

[0020] In this embodiment, the method for pre-treating the raw materials of the high-purity phenolic compounds includes: Take out the high-purity phenolic compound raw material stored at room temperature, protected from light, and in a dry place, and equilibrate it in a P2O5 desiccator for 48 hours after accurate purity determination. Place a clean weighing boat on an electronic balance. Once the balance is stable, tare the balance and zero it. Use a weighing spoon to quantitatively transfer 100 mg of raw material into the weighing boat. Once the balance is stable, read the value. Transfer the weighed raw material to a 1 L brown volumetric flask. Rinse the weighing boat several times with solvent, and transfer all the washing solution to the volumetric flask. The 1 L brown volumetric flask is pre-filled with argon gas. The weighing and transfer of raw material are carried out in an operating box under a saturated nitrogen atmosphere.

[0021] In this embodiment, the method for preparing the combined stabilizer is as follows: accurately weigh 0.5 g of butylated hydroxytoluene and transfer it to a 1 L volumetric flask, rinse with mass spectrometry-grade methanol, and completely transfer the solution to the volumetric flask; accurately weigh 1 g of formic acid and transfer it to the same volumetric flask, rinse with mass spectrometry-grade methanol, and completely transfer the solution to the same volumetric flask; then accurately weigh 0.1 g of EDTA and transfer it to the same volumetric flask, rinse with mass spectrometry-grade methanol, and completely transfer the solution to the same volumetric flask. In the actual evaluation, cross-experiments were conducted to examine different stabilizers and different sealing methods, and the changes in the mass value of the solution standard before and after packaging were examined, as shown in Table 2; the long-term stability data of the trace 10-component phenolic endocrine disruptor solution standard with different stabilizers were examined, as shown in Table 3. Table 2. Variation of stabilizer standard substance mass values ​​under different sealing methods for multi-type combined stabilizers Table 3. Long-term stability study data of the combined stabilizers The long-term stability trend of trace 10-component phenolic endocrine disruptor solution standard substances with different stabilizers is shown in the figure below. Figure 2 As shown, the results indicate that the combination of 0.05% butylated hydroxytoluene, 0.1% formic acid, and 0.01% EDTA is the optimal stabilizer.

[0022] In this embodiment, a type 1 mass spectrometry grade methanol solvent is added to S1 to about 2 / 3 of the volumetric flask volume, and the mixture is gently shaken until completely dissolved.

[0023] In this embodiment, the volume-fixing method includes: Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the graduation mark, then stop. Stop the flask and place it in a 20°C constant temperature bath for 30 min. After bringing the volume to the mark, bring it to the mark again and hold it at the temperature for 30 min to confirm that the volume has been brought to the graduation mark. Ensure that the components are evenly distributed. The volumetric solution for phenol needs to be vortexed for 10 seconds and sonicated in an ice bath for 5 seconds, repeated 3 times. The sonication in the ice bath should be at 40 kHz.

[0024] In this embodiment, the dilution method includes: Accurately transfer 10 mL of the phenolic solution to a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the mark. Stop adding the flask and place it in a 20℃ constant temperature bath for 30 min. Then, bring the volume to the mark and heat it again for 30 min. Confirm that the volume has been brought to the mark to obtain a first-degree diluted solution. Take 10 mL of the first-stage dilution solution into a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm away from the mark. Stop the flask with the stopper and place it in a 20℃ constant temperature bath for 30 min. Then, dilute to the mark and keep it in the constant temperature bath for another 30 min. Confirm that the volume has been diluted to the mark to obtain the second-stage dilution solution. Take 10 mL of the grade 2 dilution solution into a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the mark. Stop adding the flask and place it in a 20℃ constant temperature bath for 30 min. Then, bring the volume to the mark and heat it again for 30 min. Confirm that the volume has been brought to the mark to obtain the diluted phenol solution.

[0025] In this embodiment, the pretreatment method for the brown glass ampoule includes acid washing, rinsing with ultrapure water, methanol rinsing, and drying at 120°C; the acid washing uses 10% HNO3 and soaks for 24 hours; the dried ampoule is treated with 5% dimethyldichlorosilane / toluene solution for 1 hour, rinsed with methanol, and dried at 120°C for later use.

[0026] In the actual evaluation, the ampoule was rinsed 5 times with ultrapure water and rinsed 2 times with chromatographic grade methanol, and then dried at 120°C. The dried brown glass ampoule was filled with a 5% dimethyldichlorosilane toluene solution, soaked for 1 hour, rinsed 5 times with chromatographic grade methanol and rinsed 5 times with mass spectrometry grade methanol, and then dried at 120°C for later use. The purpose of the special pretreatment of brown glass ampoules is to reduce the impact of dissolved metal elements and oxidizing substances on the storage solution standard. The experiment investigated the effect of different treatment methods on the stability of the solution standard. Three pretreatment methods were investigated: Ampoule #1 was used directly without cleaning; Ampoule #2 underwent acid washing (immersion in 10% HNO3 for 24 hours), rinsing with ultrapure water, methanol rinsing, and drying at 120℃; Ampoule #3 underwent acid washing (immersion in 10% HNO3 for 24 hours), rinsing with ultrapure water, methanol rinsing, and drying at 120℃. After drying, the ampoules were treated with a 5% dimethyldichlorosilane / toluene solution for 1 hour, rinsed with methanol, and dried at 120℃ for later use. For ampoules pretreated using methods 1#, 2#, and 3#, 24 treated ampoules were randomly selected from each sample and filled with trace amounts of a 10-component phenolic endocrine disruptor solution standard. These were then sealed and stored for 6 months. Six ampoules were taken out at months 1, 2, 3, and 6, and the average value was used as the final result. The detection method was the same as in Experiment 3. The experimental results are shown in Tables 4, 5, and 6. Table 4 Results of the investigation on the pretreatment methods for ampoule #1 Table 5 Results of the investigation on the pretreatment methods for #2 ampoules Table 6 Results of the investigation on the pretreatment methods for ampoule #3 The results showed that the pretreatment method of the No. 3 ampoule was optimal, and the values ​​of the trace 10-component phenolic endocrine disruptor solution standard were stable after 6 months of storage.

[0027] In this embodiment, the 10 phenolic compounds include: 4-tert-butylphenol (CAS: 98-54-4), 4-butylphenol (CAS: 1638-22-8), 4-pentylphenol (CAS: 14938-35-3), 4-hexylphenol (CAS: 2446-69-7), 4-heptylphenol (CAS: 1987-50-4), 4-octylphenol (CAS: 1806-26-4), 4-branched nonylphenol (CAS: 84852-15-3), 4-tert-octylphenol (CAS: 140-66-9), 4-nonylphenol (CAS: 104-40-5), and bisphenol A (CAS: 80-05-7).

[0028] In this embodiment, the packaging method includes: An oxyhydrogen welding machine was used as the dispensing equipment, and the dispensing gas was a mixture of hydrogen and oxygen. Before dispensing, the diluted phenolic solution to be dispensed was frozen at -10℃ for 24 hours. After the diluted phenolic solution was thoroughly mixed, the diluted phenolic solution to be dispensed in the volumetric flask was poured into a glass storage bottle, sealed with a cap with a switch valve, and then injected into 2mL brown glass ampoules using a syringe with a switch valve. The dispensing volume was 1mL, and the ampoules were stored frozen at (-10±5)℃ in the dark. In the actual evaluation, the homogeneity of the standard substance was tested. If the total number of units prepared is N, and N≤200, at least 11 units should be sampled. The specific procedure is as follows: For the above-mentioned 1.00 μg / L trace 10-component phenolic endocrine disruptor solution standard substance, samples were randomly selected at the beginning, middle, and end of dispensing, for a total of 11 bottles for homogeneity testing. The total organic carbon content was determined using a total organic carbon analyzer, measured in random order, with each bottle measured three times. The average of the three measurements was taken as the result for one bottle. Following JJF1343-2012 "General Principles and Statistical Principles for Standard Substance Value Determination," one-way ANOVA was used for testing. The homogeneity test results are shown in Tables 7 and 8. Table 7 Results of One-Way ANOVA Table 8 Results of One-Way ANOVA The results show that: The standard substance exhibits good homogeneity, meeting the requirements for homogeneity of standard substances.

[0029] In this embodiment, a cooling sleeve is placed on the neck and below of the brown glass ampoule before dispensing.

[0030] In this embodiment, both the dilution and dispensing processes are carried out in an operating chamber under a saturated nitrogen atmosphere.

[0031] In the actual evaluation, the stability of trace 10-component phenolic endocrine disruptor solution standard substances under transportation conditions was examined. The stability of the standard substances during transportation was simulated. The specific method for short-term stability testing was as follows: within 15 days, samples stored at 2℃~10℃ and 20℃~30℃ were tested according to the principle of initially denser intervals followed by more sparse intervals. A total organic carbon analyzer was used for testing, and the instrument's operating conditions were strictly controlled during each test to minimize the impact on instrument reproducibility. Three bottles were randomly selected each time, and each bottle was measured three times. The average of the three measurements was taken as the analytical result for one bottle, and the average of the three bottle measurements was taken as the result of that test. According to the standard JJF1343-2012 "General Principles and Statistical Principles for Standard Substance Value Determination", a linear fit was made between the molar concentration c and time T based on the stability test results. If... This indicates that the slope of the straight line in the solution stability test results is not significant, and the standard substance has good stability; if This indicates that the slope of the straight line in the solution stability test results is significant, suggesting poor stability of the standard substance. The test results are shown in Tables 9 and 10. Table 9. Stability study results of trace 10-component phenolic endocrine disruptor solution standard under simulated transport conditions (2℃~10℃). Table 10 Trace 10-component phenolic endocrine disruptor solution standard at 1.00 μg / L Stability study results under simulated transportation conditions (20℃~40℃) Therefore, during summer transportation, insulated boxes with ice packs are used to ensure that the temperature does not exceed 10℃ during transportation.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a trace 10-component phenolic endocrine disruptor solution standard, characterized in that, Includes the following steps: S1. Accurately weigh 10 high-purity phenolic compounds with accurately determined purities, dissolve them in a nitrogen-atmospheric atmosphere using mass spectrometry-grade methanol solvent, and obtain dissolved phenolic standards; the mass spectrometry-grade methanol solvent comprises 0.05% butylated hydroxytoluene + 0.1% formic acid + 0.01% EDTA; the mass spectrometry-grade methanol solvent is obtained through a combined stabilizer preparation experiment; S2. Fill the volumetric flask with nitrogen gas, pour the dissolved phenolic standard into the volumetric flask, keep it at a constant temperature of 20.0℃±0.5℃ for 20 min in a constant temperature bath, and then dissolve and dilute the solution with the mass spectrometry grade methanol solvent to obtain a diluted phenolic solution. S3. The phenolic solution is gradually diluted to 1 μg / L using the mass spectrometry-grade methanol solvent to obtain a diluted phenolic solution; S4. In a nitrogen atmosphere operating chamber, the brown glass ampoules are pre-filled with argon gas. The diluted phenolic solution is then dispensed into the brown glass ampoules. Argon gas is then introduced above the ampoules containing the solution to seal the ampoules and store them frozen.

2. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The method for pre-processing the raw materials of the high-purity phenolic compounds includes: Take out the high-purity phenolic compound raw material stored at room temperature, protected from light, and in a dry place, and equilibrate it in a P2O5 desiccator for 48 hours after accurate purity determination. Place a clean weighing boat on an electronic balance. Once the balance is stable, tare the balance and zero it. Use a weighing spoon to quantitatively transfer 100 mg of raw material into the weighing boat. Once the balance is stable, read the value. Transfer the weighed raw material to a 1 L brown volumetric flask. Rinse the weighing boat several times with solvent, and transfer all the washing solution to the volumetric flask. The 1 L brown volumetric flask is pre-filled with argon gas. The weighing and transfer of raw material are carried out in an operating box under a saturated nitrogen atmosphere.

3. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The method for preparing the combined stabilizer is as follows: accurately weigh 0.5 g of butylated hydroxytoluene and transfer it to a 1 L volumetric flask, rinse with mass spectrometry grade methanol, and completely transfer it to the volumetric flask; accurately weigh 1 g of formic acid and transfer it to the above volumetric flask, rinse with mass spectrometry grade methanol, and completely transfer it to the volumetric flask; Accurately weigh 0.1 g of EDTA and transfer it to the volumetric flask mentioned above. Rinse the flask with mass spectrometry grade methanol and transfer it completely into the volumetric flask.

4. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, Add Class I mass spectrometry grade methanol solvent to S1 to about 2 / 3 of the volumetric flask volume, and shake gently until completely dissolved.

5. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The volume determination method includes: Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the graduation mark, then stop. Stop the flask and place it in a 20°C constant temperature bath for 30 min. After bringing the volume to the mark, bring it to the mark again and hold it at the temperature for 30 min to confirm that the volume has been brought to the graduation mark. Ensure that the components are evenly distributed. The volumetric solution for phenol needs to be vortexed for 10 seconds and sonicated in an ice bath for 5 seconds, repeated 3 times. The sonication in the ice bath should be at 40 kHz.

6. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The dilution method includes: Accurately transfer 10 mL of the phenolic solution to a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the mark. Stop adding the flask and place it in a 20℃ constant temperature bath for 30 min. Then, bring the volume to the mark and heat it again for 30 min. Confirm that the volume has been brought to the mark to obtain a first-degree diluted solution. Take 10 mL of the first-stage dilution solution into a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm away from the mark. Stop the flask with the stopper and place it in a 20℃ constant temperature bath for 30 min. Then, dilute to the mark and keep it in the constant temperature bath for another 30 min. Confirm that the volume has been diluted to the mark to obtain the second-stage dilution solution. Take 10 mL of the second-stage dilution solution into a 1 L brown volumetric flask. Add mass spectrometry grade methanol solvent to the volumetric flask until it is 2-3 cm from the graduation mark. Stop adding the flask and place it in a 20°C constant temperature bath for 30 min. Then, bring the volume to the mark and heat it again for 30 min. Confirm that the volume has been brought to the mark to obtain the diluted phenolic solution. The dilution is carried out in an operating chamber under a saturated nitrogen atmosphere.

7. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The method for pre-processing the brown glass ampoule includes: Pickling, rinsing with ultrapure water, rinsing with methanol, and drying at 120°C; the pickling is performed using 10% HNO3 and soaking for 24 hours; the dried ampoules are treated with 5% dimethyldichlorosilane / toluene solution for 1 hour, rinsed with methanol, and dried at 120°C for later use.

8. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The 10 phenolic compounds include: 4-tert-butylphenol, 4-butylphenol, 4-pentylphenol, 4-hexylphenol, 4-heptylphenol, 4-octylphenol, 4-branched nonylphenol, 4-tert-octylphenol, 4-nonylphenol, and bisphenol A.

9. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, The packaging method includes: An oxyhydrogen welding machine was used as the dispensing equipment, and the dispensing gas was a mixture of hydrogen and oxygen. Before dispensing, the diluted phenolic solution to be dispensed was frozen at -10℃ for 24 hours. After thoroughly mixing the diluted phenolic solution, the diluted phenolic solution to be dispensed in the volumetric flask was poured into a glass storage bottle, sealed with a cap with a switch valve, and then injected into 2mL brown glass ampoules using a syringe with a switch valve. The dispensing volume was 1mL, and the ampoules were stored frozen at (-10±5)℃ in the dark. The dispensing was carried out in an operating box under a saturated nitrogen atmosphere.

10. The method for preparing a trace 10-component phenolic endocrine disruptor solution standard substance according to claim 1, characterized in that, For the brown glass ampoules, a cooling sleeve is placed on the neck and below the neck of the ampoule before dispensing.

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