Method for determining polycyclic aromatic hydrocarbons in elastomer

Abstract

A method for determining polycyclic aromatic hydrocarbons in an elastomer, at least comprising the following steps: (1) mixing an elastomer sample with a solvent, and leaving the mixture to stand to obtain a sample solution; and (2) adding an extractant to the sample solution for extraction, standing for layering, and then taking a supernatant for gas chromatography-mass spectrometry analysis. The method is simple, does not require an additional complex pretreatment process, greatly improves determination efficiency, reduces determination costs, can be used for accurate quantitative determination of multiple polycyclic aromatic hydrocarbons in an elastomer, and is easy to promote routine monitoring of polycyclic aromatic hydrocarbons.

Description

A method for testing polycyclic aromatic hydrocarbons in elastomers Technical Field

[0001] This invention relates to the field of polycyclic aromatic hydrocarbon (PAH) detection technology, specifically a method for testing PAHs in elastomers. Background Technology

[0002] Polycyclic aromatic hydrocarbons (PAHs) are compounds in which two or more benzene rings and fused rings are linked together. They are commonly found in materials such as petrochemical products, charcoal, creosote, pharmaceuticals, dyes, rubber, plastics, lubricating oils, mold release agents, capacitor electrolytes, mineral oils, rust inhibitors, pesticides, and incompletely combusted organic compounds. They are biodegradable and cumulative, and pose "three-way" hazards (carcinogenic, teratogenic, and mutagenic). Therefore, various industries have put forward testing requirements for PAHs, including electronic and electrical products, cosmetics, water quality, and soil.

[0003] Chinese patent application (publication number CN106226418A) discloses a rapid, low-cost, simple, and efficient method for detecting polycyclic aromatic hydrocarbons (PAHs). The method includes acidification and purification steps, but it can only detect a limited range of PAHs. Chinese patent application (publication number CN116718686A) discloses a method for determining PAHs in thermoplastic elastomers. This method primarily uses solid-phase extraction (SPE) to remove additive interferences from the thermoplastic elastomers, particularly using a dedicated PAH SPE column. This column utilizes polymers with molecular imprints on PAHs, effectively adsorbing them and directly removing interfering impurities, thus directly improving the recovery rate and accuracy of PAHs. However, the sample pretreatment agent is easily lost during the detection process, the sample volume is relatively large, and the detection cost is relatively high, making it difficult to promote and implement.

[0004] Therefore, developing a simple, efficient, and low-cost method for the quantitative detection of various polycyclic aromatic hydrocarbons (PAHs) in elastomers is of great significance for promoting the routine monitoring of PAHs. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a method for testing polycyclic aromatic hydrocarbons (PAHs) in elastomers. The method is simple, requires no additional complex pretreatment processes, greatly improves detection efficiency, reduces detection costs, and can be used for the accurate quantitative detection of various PAHs in elastomers, facilitating routine monitoring of PAHs.

[0006] This invention provides a method for testing polycyclic aromatic hydrocarbons in elastomers, comprising at least the following steps:

[0007] (1) The elastomer sample is mixed with a solvent and allowed to stand to obtain a sample solution;

[0008] (2) Add extractant to the sample solution for extraction, allow it to stand and separate into layers, and then take the supernatant for gas chromatography-mass spectrometry detection and analysis.

[0009] The elastomers in this invention include thermoplastic elastomers and thermosetting elastomers;

[0010] Thermosetting elastomers include: styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene propylene rubber, butyl rubber, chloroprene rubber, and nitrile rubber.

[0011] Thermoplastic elastomers include: styrene-based thermoplastic elastomers (SBS, hydrogenated SBS (SEBS), SIS, and hydrogenated SIS), polyurethane-based thermoplastic elastomers (TPU), polyolefin-based thermoplastic elastomers (TPO), and polyamide-based thermoplastic elastomers (TPEA).

[0012] As a preferred technical solution, the solvent is selected from at least one of methanol, ethanol, isopropanol, acetone, methyl ketone, N-methylpyrrolidone, and water.

[0013] Preferably, the solvent is methanol.

[0014] As a preferred technical solution, the ratio of the mass of the elastomer sample to the volume of the solvent is 1g:(1-5)mL, preferably 1g:(1-3)mL, and most preferably 1g:2mL.

[0015] As a preferred technical solution, the standing conditions are: standing in an oven at 40-60℃ for 2-4 days.

[0016] Preferably, the settling conditions are: settling in an oven at 50°C for 3 days.

[0017] As a preferred technical solution, the extractant includes at least n-hexane and water.

[0018] Preferably, the volume ratio of hexane to water is 1:(1-4), more preferably 1:(1-2), and most preferably 1:1.

[0019] As a preferred technical solution, the extraction method is shaking extraction, the extraction temperature is 15-30℃, and the extraction time is 15-60s.

[0020] Preferably, the extraction method is shaking extraction, the extraction temperature is 25°C, and the extraction time is 30 seconds.

[0021] In this invention, polycyclic aromatic hydrocarbons include naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, benzo[a]anthracene, chrysene, benzo[a]fluoranthene, benzo[e]pyrene, indene[1,2,3-cd]pyrene, benzo[ghi]perylene, and dibenzo[a,h]anthracene. Benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[j]fluoranthene are isomers, and the three substances are combined into benzo[j]fluoranthene for calculation.

[0022] The testing method provided by this invention, through optimized pretreatment processes and controlled chromatographic detection conditions, has demonstrated validated its specificity, linearity, limit of quantitation, accuracy, precision (repeatability and intermediate precision), and solution stability for 18 polycyclic aromatic hydrocarbons (PAHs) in elastomers. The results are accurate and reliable. Specifically, by mixing the elastomer sample with a solvent and allowing it to stand, the resulting sample solution is directly extracted with an extractant before gas chromatography-mass spectrometry (GC-MS) analysis. This significantly simplifies the pretreatment process, eliminating the need for additional adsorption extraction columns and avoiding PAH loss caused by multiple transfers and evaporation concentrations. In particular, after mixing the elastomer sample with methanol and allowing it to stand for 3 days, extraction with a hexane and water combination for 15-60 seconds ensures no interference with the target analyte peak positions, resulting in high accuracy and precision. In contrast, using only hexane as the extractant affects system stability, leading to increasingly smaller peak values ​​for the target compounds and an increase in QC RSD.

[0023] As a preferred technical solution, the chromatographic parameters of the gas chromatography-mass spectrometry method include: injection port temperature of 280-320℃; injection mode of split injection with a split ratio of (8-12):1; transfer line temperature of 280-320℃; chromatographic column of HP-5MS, 30m×0.25mm, 0.25μm; column flow rate of 0.5-1.5mL / min; and temperature program of: initial temperature 70-90℃, hold for 1-3min, increase to 250-280℃ at 15-25℃ / min, increase to 300-320℃ at 5-10℃ / min, and hold for 3-8min.

[0024] Preferably, the chromatographic parameters of the gas chromatography-mass spectrometry method include: an injection port temperature of 300℃; an injection mode of split injection with a split ratio of 10:1; a transfer line temperature of 300℃; a chromatographic column of HP-5MS, 30m × 0.25mm, 0.25μm; a column flow rate of 1.0mL / min; and a temperature program of: an initial temperature of 80℃, held for 2min, increased to 260℃ at 20℃ / min, increased to 300℃ at 5℃ / min, and held for 5min.

[0025] As a preferred technical solution, the mass spectrometry parameters of the gas chromatography-mass spectrometry method include: ion source temperature of 200-250℃; quadrupole temperature of 130-180℃; solvent delay time of 3-5 min; scan mode of selected ion monitoring, with selected ions including 128 (NAP), 152 (ANY), 154 (ANA), 166 (FLU), 178 (ANT), 178 (PHE), 202 (FLT), 202 (PYR), 228 (BaA), 228 (CHR), 252 (BaP), 252 (BeP), 252 (BFA), 276 (BPE), 276 (IPY), and 278 (DBA) m / z; and scan range of 50-350 m / z.

[0026] Preferably, the mass spectrometry parameters of the gas chromatography-mass spectrometry method include: ion source temperature of 230℃; quadrupole temperature of 150℃; solvent delay time of 4 min; scan mode of selected ion monitoring, with selected ions including 128 (NAP), 152 (ANY), 154 (ANA), 166 (FLU), 178 (ANT), 178 (PHE), 202 (FLT), 202 (PYR), 228 (BaA), 228 (CHR), 252 (BaP), 252 (BeP), 252 (BFA), 276 (BPE), 276 (IPY), and 278 (DBA) m / z; and scan range of 50–350 m / z.

[0027] Furthermore, by optimizing the control of chromatographic and mass spectrometric parameters, the injection repeatability and quality control solution repeatability are good, the method is specific, the linear correlation coefficients of 18 polycyclic aromatic hydrocarbons are all ≥0.993, the recovery rate of spiked at the limit of quantitation is between 70% and 125%, and the accuracy and precision are high. Beneficial effects

[0028] 1. This invention provides a test method for polycyclic aromatic hydrocarbons in elastomers. The method is simple and does not require additional complex pretreatment processes, which greatly improves the detection efficiency and reduces the detection cost. It can be used for the accurate quantitative detection of various polycyclic aromatic hydrocarbons in elastomers and is easy to promote the daily monitoring of polycyclic aromatic hydrocarbons.

[0029] 2. The test method provided by this invention, through optimized pretreatment process and control of chromatographic detection conditions, has been verified for its specificity, linearity, limit of quantitation, accuracy, precision (repeatability and intermediate precision), and solution stability for 18 polycyclic aromatic hydrocarbons in elastomers. The detection and analysis results are accurate and reliable.

[0030] 3. This invention simplifies the pretreatment process by directly extracting the sample solution obtained by mixing the elastomer sample with a solvent and allowing it to stand. This allows for gas chromatography-mass spectrometry detection and analysis. It eliminates the need for additional adsorption extraction columns and avoids the loss of polycyclic aromatic hydrocarbons caused by multiple transfers and evaporation concentrations.

[0031] 4. This invention involves mixing the elastomer sample with methanol and allowing it to stand for 3 days, then extracting it with a combination of hexane and water for 15-60 seconds before using it for subsequent sample injection and detection. This ensures that the peak positions of the target analytes are not interfered with, resulting in a method with high accuracy and precision.

[0032] 5. This invention achieves good repeatability of injection and quality control solutions through optimized chromatographic and mass spectrometry parameter control. The method is specific, with linear correlation coefficients of ≥0.993 for all 18 polycyclic aromatic hydrocarbons. The recovery rate of spiked samples at the limit of quantitation is between 70% and 125%, and the accuracy and precision are high. Attached Figure Description

[0033] Figure 1 shows the specific chromatogram of the reagent blank solution.

[0034] Figure 2 shows the specific chromatogram of the standard curve solution (L-3).

[0035] Figure 3 shows the specific chromatogram of the sample solution.

[0036] Figure 4 shows the specific chromatogram of the solution spiked at the limit of quantitation. Detailed Implementation

[0037] Example 1

[0038] Example 1 of the present invention provides a method for testing polycyclic aromatic hydrocarbons in elastomers, comprising the following steps:

[0039] (1) The elastomer sample is mixed with a solvent and allowed to stand to obtain a sample solution;

[0040] (2) Add extractant to the sample solution for extraction, allow it to stand and separate into layers, and then take the supernatant for gas chromatography-mass spectrometry detection and analysis.

[0041] The thermoplastic elastomer is a butyl rubber stopper.

[0042] The solvent is methanol, and the mass ratio of the elastomer sample to the volume of the solvent is 1 g: 2 mL.

[0043] The conditions for settling are: settling in an oven at 50°C for 3 days.

[0044] The extractant is n-hexane and water, and the volume ratio of n-hexane to water is 1:1.

[0045] The extraction method was shaking extraction, the extraction temperature was 25℃, and the extraction time was 30s.

[0046] The chromatographic parameters of the gas chromatography-mass spectrometry method include: injection port temperature of 300℃; injection mode of split injection with a split ratio of 10:1; injection volume of 1μL; carrier gas of He; transfer line temperature of 300℃; column of HP-5MS, 30m×0.25mm, 0.25μm; column flow rate of 1.0mL / min; and temperature program of: initial temperature of 80℃, hold for 2min, increase to 260℃ at 20℃ / min, increase to 300℃ at 5℃ / min, and hold for 5min.

[0047] The mass spectrometry parameters of the gas chromatography-mass spectrometry method include: ion source temperature of 230℃; quadrupole temperature of 150℃; solvent delay time of 4 min; scan mode of selected ion monitoring, with selected ions including 128 (NAP), 152 (ANY), 154 (ANA), 166 (FLU), 178 (ANT), 178 (PHE), 202 (FLT), 202 (PYR), 228 (BaA), 228 (CHR), 252 (BaP), 252 (BeP), 252 (BFA), 276 (BPE), 276 (IPY), and 278 (DBA) m / z; and scan range of 50–350 m / z.

[0048] Comparative Example 1

[0049] Comparative Example 1 of the present invention provides a method for testing polycyclic aromatic hydrocarbons in an elastomer. The specific implementation method is the same as that in Example 1, except that the extractant is n-hexane.

[0050] Performance testing

[0051] I. The method provided in Example 1 is validated as follows.

[0052] (I) Materials and Methods

[0053] 1. Standard reference material information: Please refer to Table 1-1 below for standard reference material information.

[0054] Table 1-1 Information on Standard Materials

[0055] Table 1-2 Target Information

[0056] 2. Standard test solution information: Please refer to Table 1-3 below for standard test solution information.

[0057] Table 1-3 Standard Test Solution Information

[0058] 3. Instrument information: Please refer to Table 1-4 below for instrument information.

[0059] Table 1-4 Instrument Information

[0060] 4. Reagent information: See Table 1-5 below for reagent information.

[0061] Table 1-5 Reagent Information

[0062] (II) Verification Process

[0063] 1. Preparation of analytical solutions

[0064] 1.1 Diluent: n-Hexane

[0065] 1.2 Extractant: Purified water, n-hexane

[0066] 1.3 Standard Substance Solution

[0067] 1.3.1 Mixed Standard A of 18 Polycyclic Aromatic Hydrocarbons

[0068] Measure 100.0 μL of a mixed standard of 18 polycyclic aromatic hydrocarbons into a 10 mL volumetric flask, dilute to the mark with n-hexane, mix well, and label as Mixed Standard A of 18 Polycyclic Aromatic Hydrocarbons.

[0069] 1.3.2 Mixed Standard B of 18 Polycyclic Aromatic Hydrocarbons

[0070] Measure 100.0 μL of a mixed standard of 18 polycyclic aromatic hydrocarbons into a 10 mL volumetric flask, dilute to the mark with n-hexane, mix well, and label as Mixed Standard B of 18 Polycyclic Aromatic Hydrocarbons.

[0071] 1.4 Standard Curve Solution

[0072] According to Table 2-1, measure out 18 kinds of polycyclic aromatic hydrocarbon mixed standard A into different 10ml volumetric flasks, dilute to the mark with diluent, shake well, and prepare standard curve solutions. The concentrations of the standard substances in the standard curve solutions are shown in Table 2-2 below.

[0073] Table 2-1 Preparation of Standard Curve Solutions

[0074] Table 2-2 Concentration of Standard Substances in Standard Curve Solutions

[0075] 1.5 System Suitability (SST) Solution

[0076] Take 1 ml of L-3 into the injection vial.

[0077] 1.6 Quality Control (QC) Solution

[0078] Take 1 ml of L-3 into the injection vial.

[0079] 1.7 Limit of Quantitation (LOQ) Solution

[0080] L⁻¹ was used as the limit of quantitation solution.

[0081] 1.8 Sample Mother Solution

[0082] Take 500ml of methanol and put it into a 500ml solvent bottle.

[0083] 1.9 Sample Solution

[0084] Take 1g of elastomer and put it into 2ml of methanol for processing. Place it in a 50℃ oven for 3 days. Take 5.000ml of the elastomer into a sample vial, add 5.000ml each of n-hexane and purified water, shake to extract for 30s, let stand until the layers separate, and take 1ml of the supernatant into a sample vial.

[0085] 1.10 Reagent blank solution

[0086] Transfer 5.000 ml of methanol to a sample vial, add 5.000 ml each of n-hexane and purified water, shake to extract for 30 seconds, let stand until the layers separate, and take 1 ml of the supernatant into a vial.

[0087] 1.11 Accuracy Solution

[0088] 1.11.1 Low Concentration Level Accuracy Solution

[0089] Low-concentration level accuracy solution: Measure 5.000 ml of the sample stock solution into a 10 ml volumetric flask, add 50.0 μl of a mixed standard A of 18 polycyclic aromatic hydrocarbons, dilute to the mark with the sample stock solution, and shake well. Transfer 5.000 ml of the above solution to a sample vial, add 5.000 ml each of the extraction solvent n-hexane and purified water, shake to extract for 30 s, allow to stand until layering, and take 1 ml of the supernatant into a vial. Prepare three parallel solutions using the same method to obtain low-concentration level accuracy solution 1 to low-concentration level accuracy solution 3.

[0090] 1.11.2 Medium Concentration Level Accuracy Solution

[0091] Medium-concentration level accuracy solution: Measure 5.000 ml of the sample stock solution into a 10 ml volumetric flask, add 0.0 μl of a mixed standard A15 of 18 polycyclic aromatic hydrocarbons, dilute to the mark with the sample stock solution, and shake well. Transfer 5.000 ml of the above solution to a sample vial, add 5.000 ml each of the extraction solvent n-hexane and purified water, shake to extract for 30 s, allow to stand until layering, and take 1 ml of the supernatant into a vial. Prepare three parallel solutions using the same method to obtain medium-concentration level accuracy solution 1 to medium-concentration level accuracy solution 3.

[0092] 1.11.3 High-concentration level accuracy solution

[0093] High-concentration level accuracy solution: Measure 5.000 ml of the sample stock solution into a 10 ml volumetric flask, add 0.0 μl of a mixed standard A20 of 18 polycyclic aromatic hydrocarbons, dilute to the mark with the sample stock solution, and shake well. Transfer 5.000 ml of the above solution to a sample vial, add 5.000 ml each of the extraction solvent n-hexane and purified water, shake to extract for 30 s, allow to stand until layering, and take 1 ml of the supernatant into a vial. Prepare three parallel solutions using the same method to obtain high-concentration level accuracy solution 1 to high-concentration level accuracy solution 3.

[0094] 1.12 The quantitation limit spiking solutions were the low concentration level accuracy solutions 1 to 3.

[0095] 1.13 Specific solutions: Reagent blank solution, sample solution 1, standard curve solution (L-3), and limit of quantitation spiked solution 1 were used as specific solutions.

[0096] 1.14 Reproducible Solution

[0097] Measure 5.000 ml of the sample stock solution into a 10 ml volumetric flask, add 150.0 μl of a mixed standard A of 18 polycyclic aromatic hydrocarbons, dilute to the mark with the sample stock solution, and shake well. Transfer 5.000 ml of the above solution to a sample vial, add 5.000 ml each of the extraction solvent n-hexane and purified water, shake to extract for 30 s, allow to stand until layering, and take 1 ml of the supernatant into a vial. Prepare a total of 6 solutions in parallel using the same method to obtain repeatable solutions 1 to 6.

[0098] 1.15 Solution stability

[0099] Take the above repeatable solutions 1 to 6 and place them at 2 to 8°C for 8 days to obtain solution stability solutions 1 to 6 in sequence.

[0100] 1.16 The intermediate precision solutions were prepared by a second analyst on different days and analyzed using the same instrument. 5.000 ml of the sample stock solution was measured into a 10 ml volumetric flask, 150.0 μl of a mixed standard B of 18 polycyclic aromatic hydrocarbons was added, and the solution was diluted to the mark with the sample stock solution and shaken well. 5.000 ml of the above solution was transferred to a sample vial, and 5.000 ml each of the extraction solvent n-hexane and purified water were added. The mixture was shaken and extracted for 30 seconds, allowed to stand until layering, and 1 ml of the upper layer was collected into a vial. Six solutions were prepared in parallel using the same method to obtain intermediate precision solutions 1 through 6.

[0101] 2 Instrumental Analysis Methods

[0102] The parameters for the instrumental analysis methods are shown in Tables 2-3 and 2-4 below.

[0103] Table 2-3 Chromatographic parameters for GC-MS

[0104] Table 2-4 Mass Spectrometry Parameters of GC-MS

[0105] (III) Results Analysis

[0106] 1. System Applicability

[0107] 1.1 Results Analysis

[0108] 1.1.1 Sample Injection Repeatability

[0109] Acceptance criteria for injection repeatability: The RSD of the target analyte peak area must not exceed 10%. The analytical results show that the injection repeatability meets the acceptance criteria. The injection repeatability results are shown in Table 3-1 below.

[0110] Table 3-1 Results of injection repeatability

[0111] 1.1.2 Quality Control

[0112] The repeatability acceptance criterion for the quality control solution is that the RSD of the target analyte peak area must not exceed 15%. The analytical results indicate that the quality control test results meet the acceptance criteria.

[0113] The repeatability results of the quality control solution are shown in Tables 3-2 and 3-3 below.

[0114] Table 3-2 Results of Repeatability of Quality Control Solutions - 1

[0115] Table 3-3 Results of repeatability of quality control solutions - 2

[0116] 2. Exclusivity

[0117] 2.1 Results Analysis

[0118] Acceptance criteria for specificity: The peak positions of the target analyte in the reagent blank solution, standard curve solution (L-3), sample solution, and limit-of-quantitation (LOQ) spiked solution should not exhibit significant interference; the measured value of the target analyte in the reagent blank solution should not exceed 1 / 3 of the LOQ. The analytical results show that the specificity test results meet the acceptance criteria. Specificity results are shown in Tables 3-4 and 3-5 below, and the specificity chromatogram is shown in Figure 1-4.

[0119] Table 3-4 Results of Specificity 1

[0120] Table 3-5 Results of Specificity 2

[0121] 3.1 Results Analysis

[0122] The acceptance criterion for linearity is a correlation coefficient of not less than 0.99. The analysis results show that the linearity test results meet the acceptance criteria. The linearity results are shown in Table 3-6 below.

[0123] Table 3-6 Results of Linearity

[0124] 4 Limit of Quantification

[0125] 4.1 Results Analysis

[0126] Report the signal-to-noise ratio of the target analyte in the limit of quantitation (LOQ) solution, and calculate the recovery rate and RSD of the recovery rate in the LOQ spiked solution. Acceptance criteria for LOQ: signal-to-noise ratio not less than 10; LOQ spiked recovery rate between 70% and 125%, with an RSD not greater than 15%. The analytical results show that the LOQ test results meet the acceptance criteria. See Table 3-7 below for the LOQ results. See Table 3-8 below for the LOQ spiked solution results.

[0127] Table 3-7 Results of the Limit of Quantification

[0128] Table 3-8 Results of solutions spiked at the limit of quantitation

[0129] 5. Accuracy

[0130] 5.1 Results Analysis

[0131] Accuracy acceptance criteria: recovery rate between 70% and 125%, with an RSD of recovery rate not exceeding 15%. The analytical results show that the accuracy test results meet the acceptance criteria. The accuracy results are shown in Table 3-9 below.

[0132] Table 3-9 Results of Accuracy Solution

[0133] 5.2 Calculation formula: Recovery rate = (Measured amount (μg) - Background (μg)) ÷ Added (μg) × 100%;

[0134] When the target analyte is not detected in the sample solution, the recovery rate is calculated with a background of 0.000.

[0135] 6. Precision (Repeatability)

[0136] 6.1 Results Analysis

[0137] Repeatability acceptance criteria: RSD must not exceed 15%. The analytical results show that the precision (repeatability) test results meet the acceptance criteria. The repeatability results are shown in Table 3-10 below. Table 3-10 Repeatability Results.

[0138] Table 3-10 Results of Repeatability

[0139] 7. Precision (Intermediate Precision)

[0140] 7.1 Results Analysis

[0141] Intermediate precision acceptance criteria: RSD must not exceed 22%. The analytical results show that the precision (intermediate precision) test results meet the acceptance criteria. The intermediate precision results are shown in Table 3-11 below.

[0142] Table 3-11 Results of intermediate precision

[0143] 8 Solution stability

[0144] 8.1 Results Analysis

[0145] Solution stability acceptance criteria: RSD must not exceed 22%. The analytical results show that the solution stability test results meet the acceptance criteria. The solution stability results are shown in Table 3-12 below.

[0146] Table 3-12 Results of solution stability

[0147] 9 Conclusions

[0148] The specificity, linearity, limit of quantitation, accuracy, precision (repeatability and intermediate precision) and solution stability of the analytical methods for 18 polycyclic aromatic hydrocarbons in the methanol extract of elastomers were validated using gas chromatography-mass spectrometry (GC-MS). The results of all validation indicators met the requirements of the acceptance criteria.

[0149] 2. Methodological validation was performed on the method provided in Comparative Example 1. The validation method was the same as in Example 1. The system suitability did not meet the requirements. Before testing with the method provided in Comparative Example 1, the results of the injection repeatability are shown in Table 3-13. The results showed that the system was stable. Quality control test was performed. The repeatability results of the quality control solution are shown in Table 3-14 (QC-1). tRSD (%)-1 was qualified. After testing with the method provided in Comparative Example 1, quality control test was performed. The repeatability results of the quality control solution are shown in Table 3-14 (QC-1). tRSD (%)-1 was unqualified, which led to the instability of the detection system. No further methodological validation was performed.

[0150] Table 3-13 Results of injection repeatability

[0151] Table 3-14 Results of repeatability of quality control solutions

Claims

1. A method for testing polycyclic aromatic hydrocarbons in an elastomer, characterized in that, At least the following steps are included: (1) The elastomer sample is mixed with a solvent and allowed to stand to obtain a sample solution; (2) Add an extractant to the sample solution for extraction, allow it to stand and separate into layers, and then take the supernatant for gas chromatography-mass spectrometry analysis; the solvent is methanol; the standing conditions are: stand in an oven at 40-60℃ for 2-4 days; the extractant is n-hexane and water, and the volume ratio of n-hexane to water is 1:(1-4); the extraction method is shaking extraction, the extraction temperature is 15-30℃, and the extraction time is 15-60s; the elastomer is a thermosetting elastomer.

2. The method for testing polycyclic aromatic hydrocarbons in elastomers according to claim 1, characterized in that, The mass ratio of the elastomer sample to the volume of the solvent is 1 g: (1-5) mL.

3. The method for testing polycyclic aromatic hydrocarbons in elastomers according to claim 1, characterized in that, The chromatographic parameters of the gas chromatography-mass spectrometry method include: injection port temperature of 280-320℃; injection mode of split injection with a split ratio of (8-12):1; transfer line temperature of 280-320℃; column of HP-5MS, 30m×0.25mm, 0.25μm; column flow rate of 0.5-1.5mL / min; and temperature program of: initial temperature 70-90℃, hold for 1-3min, increase to 250-280℃ at 15-25℃ / min, increase to 300-320℃ at 5-10℃ / min, and hold for 3-8min.

4. The method for testing polycyclic aromatic hydrocarbons in elastomers according to claim 3, characterized in that, The injection port temperature is 300℃; the split ratio is 10:1; the transfer line temperature is 300℃; the column flow rate is 1.0 mL / min; the temperature program is as follows: initial temperature 80℃, hold for 2 min, increase to 260℃ at 20℃ / min, increase to 300℃ at 5℃ / min, and hold for 5 min.

5. The method for testing polycyclic aromatic hydrocarbons in elastomers according to claim 1, characterized in that, The mass spectrometry parameters of the gas chromatography-mass spectrometry method include: ion source temperature of 200-250℃; quadrupole temperature of 130-180℃; solvent delay time of 3-5 min; and selected ion monitoring mode. The selected ions include: NAP: 128 m / z, ANY: 152 m / z, ANA: 154 m / z, FLU: 166 m / z, ANT: 178 m / z, PHE: 178 m / z, FLT: 202 m / z, PYR: 202 m / z, BaA: 228 m / z, CHR: 228 m / z, BaP: 252 m / z, BeP: 252 m / z, BFA: 252 m / z, BPE: 276 m / z, IPY: 276 m / z, and DBA: 278 m / z.

6. The method for testing polycyclic aromatic hydrocarbons in elastomers according to claim 5, characterized in that, The ion source temperature is 230℃; the quadrupole temperature is 150℃; and the solvent delay time is 4 min.

Images