A method for detecting tris(tribromophenoxy)triazine in plastics

Abstract

The invention discloses a method for detecting tris (tribromophenoxy) triazine in plastic, comprising the following steps: S1, plastic sample is mixed with extraction solvent, extracted, and sample solution to be tested is obtained after filtration;Wherein, the extraction solvent is one of n-hexane-acetone mixed solution, n-hexane or dichloromethane;S2, the sample solution to be tested is subjected to gas chromatography and mass spectrometry. The analysis and testing method used in the present invention has the characteristics of low detection limit, good precision, and high sample spike recovery rate, meets the test requirements of tris (tribromophenoxy) triazine in plastic, and the target compound presents a good linear relationship within the range of 1.0~15.0mg / L;Detection limit and quantitative limit are both relatively low, with a detection limit of 0.1586mg / kg and a quantitative limit of 0.5288mg / kg;Relative standard deviation is less than 5.3%;Sample spike recovery rate is 94.5%~112.1%.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis and detection, and in particular relates to a method for detecting tris(tribromophenoxy)triazine in plastics. Background Art

[0002] Plastic products are widely used in daily life, and plastic additives play an important role in plastic processing, such as various plasticizers, colorants, heat stabilizers, synergists, etc. With the rise of a large number of chemical additives, their harm to human health and the environment has gradually received attention. A scientific research team has compiled a comprehensive database of more than 16,000 plastic chemicals, which are used to make plastics and additives such as stabilizers and colorants, of which more than 4,000 chemicals are dangerous. Therefore, in order to ensure the safety of the production and use of plastic products and additives, various parts of the world have successively introduced regulations on the control of the use of plastic additives, such as the well-known RoHS, POPs, and the Stockholm Convention. Among them, tris(tribromophenoxy)triazine is an additive flame retardant with excellent performance and a wide range of uses. It can be used in thermoplastics and rubbers, as well as thermosetting resins. Its notable characteristics are high temperature resistance, good thermal and light stability, good compatibility with resins, can improve the impact strength of products, can improve the colorability of products, does not affect the transparency of thermoplastics, and has long-lasting antistatic properties and good processing properties. At present, the research on tris(tribromophenoxy)triazine as a plastic additive is all aimed at synthesis direction and simple material characterization, and no reports on the detection of its content have been found. Therefore, it is very necessary to establish a method to determine the content of tris(tribromophenoxy)triazine in plastic materials. Summary of the invention

[0003] In order to overcome the problems existing in the prior art, the object of the present invention is to provide a method for detecting tris(tribromophenoxy)triazine in plastics.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The present invention provides a method for detecting tris(tribromophenoxy)triazine in plastics, comprising the following steps:

[0006] S1. Mixing the plastic sample with an extraction solvent, extracting, and filtering to obtain a sample solution to be tested; wherein the extraction solvent is one of a n-hexane-acetone mixed solution, n-hexane or dichloromethane;

[0007] S2. subjecting the sample solution to be tested to gas chromatography and mass spectrometry.

[0008] Preferably, the method further comprises cutting the plastic sample into pieces, wherein the size of the cut pieces is no larger than 5 mm×5 mm×5 mm.

[0009] Preferably, the volume ratio of n-hexane to acetone in the n-hexane-acetone mixed solution is 1:(0.5-2).

[0010] More preferably, the volume ratio of n-hexane to acetone in the n-hexane-acetone mixed solution is 1:(0.8-1.2).

[0011] Preferably, the extraction process conditions are selected from one or more of the following:

[0012] A) Extraction is performed by ultrasonic extraction;

[0013] B) The ratio of plastic sample to extraction solution is 1g: (30-100mL);

[0014] C) extraction time is 50-80min;

[0015] D) The extraction temperature is 15-40°C.

[0016] Preferably, the filtration is carried out using a microporous membrane filtration of ≤0.45 μm.

[0017] Preferably, the chromatographic column used in the gas chromatography determination is a DB-5HT separation chromatographic column.

[0018] More preferably, the DB-5HT separation chromatographic column has a length of 15 m, a membrane thickness of 0.1 μm, and an inner diameter of 0.25 mm.

[0019] The present invention adopts DB-5HT type separation chromatographic column as gas chromatographic column, and the chromatographic column uses (5%-phenyl)-dimethylpolysiloxane as stationary phase, has good performance in various analytical processes, and can provide extreme peak shape and rapid elution for high boiling point components. The precisely designed polyimide coated fused quartz tube enables the chromatographic column to have an operating temperature range of -60°C to 400°C.

[0020] Preferably, the temperature raising program of the chromatographic column temperature measured by gas chromatography includes: initial temperature 40±5°C, maintaining for 3±0.5min, heating to 320±10°C at 23±5°C / min, and maintaining for 5±0.5min.

[0021] Preferably, the gas chromatography conditions for the gas chromatography determination are selected from one or more of the following:

[0022] A) Inlet temperature: 300±10℃;

[0023] B) Carrier gas: helium with a purity of 99.999%;

[0024] C) Injection mode: Pulse splitless

[0025] D) Injection volume: (1.0±0.1) μL;

[0026] E) Column flow rate: (1.2±0.1) mL / min, constant flow.

[0027] Preferably, the mass spectrometry conditions for the mass spectrometry are selected from one or more of the following:

[0028] A) Ion source: electron bombardment source;

[0029] B) Ion source temperature: (230±5)℃;

[0030] C) Interface temperature: (280±5)℃;

[0031] D) Quadrupole temperature: (150±5)℃;

[0032] E) Solvent delay time: 2-3min;

[0033] F) Scan mode: Select ion SIM mode acquisition.

[0034] Preferably, in the mass spectrometry, the mass-to-charge ratios of the qualifier ions of the tris(tribromophenoxy)triazine are 577.85 and 987.80, and the mass-to-charge ratio of the quantifier ion is 737.80.

[0035] Preferably, the method further comprises the following steps: subjecting a matrix standard working solution of tris(tribromophenoxy)triazine to gas chromatography and mass spectrometry analysis to obtain a standard curve with peak area as the ordinate and concentration as the abscissa; and testing the plastic sample to be tested according to the standard curve to measure the content of tris(tribromophenoxy)triazine in the plastic sample to be tested.

[0036] The beneficial effects of the present invention are:

[0037] The invention establishes a method for detecting tris(tribromophenoxy)triazine in plastics. The method adopts a mixed solution of n-hexane-acetone, n-hexane or dichloromethane as an extraction solution for ultrasonic extraction, which can effectively extract tris(tribromophenoxy)triazine in a plastic sample to be tested. Then, the extract is analyzed by a gas chromatography-mass spectrometer (GC-MS). The analytical test method used has the characteristics of low detection limit, good precision and high sample spike recovery rate, and meets the test requirements of tris(tribromophenoxy)triazine in plastics. The target compound presents a good linear relationship (r2>0.9975) in the range of 1.0-15.0 mg / L; the detection limit and the quantitative limit are both low, the detection limit is 0.1586 mg / kg, and the quantitative limit is 0.5288 mg / kg; the relative standard deviation is less than 5.3%; and the sample spike recovery rate is 94.5%-112.1%. The detection method of the invention fills the gap in the detection technology of tris(tribromophenoxy)triazine in plastics. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The gas chromatogram of tris(tribromophenoxy)triazine analyzed by DB-5HT-15m column;

[0039] Figure 2 The effect of different extraction solvents on the extraction efficiency of tris(tribromophenoxy)triazine;

[0040] Figure 3 The effect of different ultrasonic time on the extraction efficiency. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below through specific examples. The raw materials used in the following examples, unless otherwise specified, can be obtained from conventional commercial sources or prepared and separated by simple synthesis; the processes used, unless otherwise specified, are conventional processes in the art.

[0042] Instruments and reagents

[0043] n-Hexane-acetone mixed solution: n-Hexane and acetone were mixed in a volume ratio of 1:1.

[0044] Standard stock solution: Accurately weigh 10 mg (accurate to 0.1 mg) of tris(tribromophenoxy)triazine standard substance, dissolve it in a mixed solution of n-hexane-acetone and dilute it to a 10 mL volumetric flask to obtain a 1000 mg / L stock solution of the standard substance, and store it in a refrigerator at 0-8°C away from light.

[0045] Standard working solution: Dilute the standard stock solution step by step with a n-hexane-acetone mixed solution to obtain a series of standard working solutions of 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, and 15.0 mg / L.

[0046] Example 1

[0047] This embodiment provides a method for detecting tris(tribromophenoxy)triazine in plastics. The detection method is as follows:

[0048] 1. Preparation of extract

[0049] Take a representative plastic sample and cut it into pieces with a size no larger than 2mm×2mm×2mm. Accurately weigh 0.1g of the sample (accurate to 0.1mg) and put it into a sample bottle, and add 5mL of n-hexane:acetone (1:1). After tightening the bottle cap, put the sample bottle into an ultrasonic cleaner. After ultrasonic cleaning for 60 minutes at room temperature, take 1mL of the extracted solution and filter it through a 0.45μm filter membrane, and then directly use a gas chromatograph-mass spectrometer GC-MS for determination.

[0050] 2. Gas chromatography-mass spectrometry conditions

[0051] (1) Gas chromatography conditions

[0052] Chromatographic column: DB-5HT (length 15m, film thickness 0.1μm, inner diameter 0.25mm); injection port temperature: 300℃; carrier gas: helium (purity 99.999%); injection mode: pulsed non-divided flow; column flow rate: 1.2mL / min; heating program: initial temperature 40℃ (maintained for 3min), heated to 320℃ at 23℃ / min (maintained for 5min).

[0053] (2) Mass spectrometry conditions

[0054] The standard working solution of tris(tribromophenoxy)triazine (mass concentration of 10.0 mg / L) was fully scanned in the range of m / z 50 to 1050 to obtain a total ion chromatogram, and the characteristic fragment ions of the substance to be tested were selected as the target monitoring ions for qualitative and quantitative analysis: the fragment ions m / z 577.85 and 987.80 of tris(tribromophenoxy)triazine were used as qualitative ions, and the fragment ion m / z 737.80 was used as the quantitative ion.

[0055] Electron impact ion source (EI); ion source temperature: 230°C; quadrupole temperature: 150°C; scanning range m / z: 50-1050; solvent delay 2-3 min, SIM ion m / z: 737.80, 577.85, 987.80.

[0056] 3. Test results

[0057] (1) Gas phase detection results are as follows Figure 1 As shown, the substance to be tested has a peak at 17.9 min, with a good peak shape and high response, and the analysis time can be controlled within 20 min.

[0058] (2) Linear equation and detection limit

[0059] Under the optimized conditions, the linear range and minimum detection limit test of tri(tribromophenoxy)triazine were carried out. The content was calculated by regression analysis based on the concentration of tri(tribromophenoxy)triazine in the standard working solution as the horizontal coordinate and the area of ​​tri(tribromophenoxy)triazine in the chromatogram as the vertical coordinate to obtain the standard working curve, thereby quantitatively obtaining the concentration of tri(tribromophenoxy)triazine in the extract. The linear equation and correlation coefficient of the obtained test substance are shown in Table 1. It can be seen from the data in the table that within the linear range of 1.0mg / L to 15.0mg / L, tri(tribromophenoxy)triazine showed a good linear relationship with a correlation coefficient of 0.9975. On this basis, the detection limit (LOD) and quantification limit (LOQ) of the standard substance were determined by 3 times and 10 times the signal-to-noise ratio (S / N), and the method detection limit was 0.1586mg / kg and the quantification limit was 0.5288mg / kg respectively.

[0060] Table 1 Linear equation, correlation coefficient, detection limit and quantification limit

[0061] Target compound Linear equations <![CDATA[Coefficient of correlation r 2 > LOD(mg / kg) LOQ (mg / kg) Tris(tribromophenoxy)triazine <![CDATA[Y=1.0×10 3 X-1.1×10 3 ]]> 0.9975 0.1586 0.5288

[0062] (3) Method accuracy and precision

[0063] The recovery experiment in this study was carried out by blank matrix spike experiment. Plastic samples without tris(tribromophenoxy)triazine to be tested were selected as blank matrix, and three different spike concentration levels (1.0 mg / L, 5.0 mg / L, 15.0 mg / L) were set. Each spike level was tested three times in parallel (n=3) to conduct precision experiments. Under the three spike levels, the spike recovery of tris(tribromophenoxy)triazine was 94.5% to 112.1%, and the standard deviation of the recovery was no more than 5.3%, indicating that the test method has high accuracy and can meet the test requirements.

[0064] (4) Sample analysis

[0065] According to the test method, six plastic samples from the same batch were tested and the target substance tris(tribromophenoxy)triazine was detected in all samples, but the detected contents were different. The specific results are shown in Table 2, and the content range is between 285-304 mg / kg.

[0066] Table 2 Tris(tribromophenoxy)triazine in plastic samples

[0067] Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Mass(g) 0.1016 0.1024 0.1031 0.1010 0.1007 0.1008 Volume of extraction solution added (mL) 5 5 5 5 5 5 Sample reading concentration (mg / L) 5.8111 6.0884 5.9168 6.1334 6.0919 6.0537 Final concentration of target substance (mg / kg) 285.98 297.29 286.94 303.63 302.48 300.28

[0068] Example 2

[0069] The difference between this embodiment and embodiment 1 is that toluene, tetrahydrofuran, n-hexane, dichloromethane and acetonitrile are selected as extraction solvents in the preparation of the extract, and the extraction efficiency of tris(tribromophenoxy)triazine in the sample by different extraction solvents is investigated. The results are as follows: Figure 2 shown.

[0070] Among the six extraction solvents, the extraction efficiency of the n-hexane-acetone mixed solution of Example 1 is the highest, and the average extraction efficiency of the test substance can reach 102%, followed by dichloromethane, n-hexane and toluene, and the average extraction efficiency of the test substance can reach more than 85%, while the average extraction efficiency of tetrahydrofuran and acetonitrile is less than 60%.

[0071] Example 3

[0072] The difference between this embodiment and embodiment 1 is that the ultrasonic time (extraction time) is selected to be 30min, 45min, 75min, and 90min, and the extraction efficiency of tris(tribromophenoxy)triazine in the sample is investigated at different ultrasonic times. The results are as follows: Figure 3 shown.

[0073] By comparing the test results, it can be found that the extraction efficiency of the analyte can reach 90% when the ultrasonic time is 60 minutes. When the ultrasonic time exceeds 60 minutes, the extraction efficiency of the analyte is slightly improved but the difference is not large. Therefore, after comprehensive consideration, the ultrasonic 60 minutes is finally selected as the extraction condition for the pretreatment.

[0074] Comparative Example 1

[0075] The difference between this comparative example and Example 1 is that DB-624 and DB-5HT-30m are respectively selected as chromatographic columns to investigate the influence of different chromatographic columns on the chromatographic peak of tris(tribromophenoxy)triazine.

[0076] The results show that when using the DB-624 chromatographic column, due to the high boiling point of the analyte, no chromatographic peak of the analyte was found at the tolerance temperature of the chromatographic column; when using the DB-5HT-30m chromatographic column, the column is too long, resulting in the sample staying in the column for too long, causing the analyte to decompose and no peak.

[0077] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for detecting tris(tribromophenoxy)triazine in plastics, characterized in that: The following steps are involved: S1. Mixing the plastic sample with an extraction solvent, extracting, and filtering to obtain a sample solution to be tested; wherein the extraction solvent is one of a n-hexane-acetone mixed solution, n-hexane or dichloromethane; S2. subjecting the sample solution to be tested to gas chromatography and mass spectrometry.

2. The method for detecting tris(tribromophenoxy)triazine in plastic according to claim 1, characterized in that: The volume ratio of n-hexane to acetone in the n-hexane-acetone mixed solution is 1:(0.5-2).

3. The method for detecting tris(tribromophenoxy)triazine in plastic according to claim 1, characterized in that: The extraction process conditions are selected from one or more of the following: A) Extraction is performed by ultrasonic extraction; B) The ratio of plastic sample to extraction solution is 1g: (30-100mL); C) extraction time is 50-80min; D) The extraction temperature is 15-40°C.

4. The method for detecting tris(tribromophenoxy)triazine in plastic according to claim 1, characterized in that: The filtration is carried out using a microporous membrane filtration of ≤0.45 μm.

5. The method for detecting tris(tribromophenoxy)triazine in plastics according to claim 1, characterized in that: The chromatographic column used in the gas chromatography determination is a DB-5HT separation chromatographic column.

6. The method for detecting tris(tribromophenoxy)triazine in plastics according to claim 1, characterized in that: The temperature raising procedure of the chromatographic column temperature measured by the gas chromatography includes: initial temperature 40±5°C, maintaining for 3±0.5min, heating to 320±10°C at 23±5°C / min, and maintaining for 5±0.5min.

7. The method for detecting tris(tribromophenoxy)triazine in plastics according to claim 1, characterized in that: The gas chromatography conditions of the gas chromatography determination are selected from one or more of the following: A) Inlet temperature: 300±10℃; B) Carrier gas: helium with a purity of 99.999%; C) Injection mode: Pulse splitless D) Injection volume: (1.0±0.1) μL; E) Column flow rate: (1.2±0.1) mL / min, constant flow.

8. The method for detecting tris(tribromophenoxy)triazine in plastics according to claim 1, characterized in that: The mass spectrometry conditions for the mass spectrometry are selected from one or more of the following: A) Ion source: electron bombardment source; B) Ion source temperature: (230±5)℃; C) Interface temperature: (280±5)℃; D) Quadrupole temperature: (150±5)℃; E) Solvent delay time: 2-3min; F) Scan mode: Select ion SIM mode acquisition.

9. The method for detecting tris(tribromophenoxy)triazine in plastics according to claim 8, characterized in that: In the mass spectrometry, the mass-to-charge ratios of the qualifier ions of the tris(tribromophenoxy)triazine are 577.85 and 987.80, and the mass-to-charge ratio of the quantifier ion is 737.

80.

10. The method for detecting tris(tribromophenoxy)triazine in plastics according to claim 1, characterized in that: The method also includes the following steps: subjecting a matrix standard working solution of tris(tribromophenoxy)triazine to gas chromatography and mass spectrometry analysis to obtain a standard curve with peak area as the ordinate and concentration as the abscissa; and testing a plastic sample to be tested according to the standard curve to measure the content of tris(tribromophenoxy)triazine in the plastic sample to be tested.

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