Method for detecting content of quasi-binary bromo-alcohol in electronic waste recycled material

Abstract

The invention relates to a method for detecting the content of quasi-binary brominated alcohol in electronic waste recycled materials, which comprises the following steps: (1) mixing a quasi-binary brominated alcohol standard substance with a solvent to prepare a standard working solution; the method comprises the following steps: extracting binary-like brominated alcohol in the electronic waste recovered material, and preparing a to-be-detected sample solution; and (2) carrying out ultra-high performance liquid chromatography-mass spectrometry detection analysis on the standard working solution and the to-be-detected sample solution obtained in the step (1), and calculating according to a standard curve to obtain the content of the binary bromohydrin-like in the electronic waste recycled material, the binary bromo-alcohol-like compound comprises 2, 2-bis (bromomethyl)-1, 3-propylene glycol and / or diisooctyl ester-2, 3, 4, 5-tetrabromobenzoic acid, and the diisooctyl ester-2, 3, 4, 5-tetrabromobenzoic acid is used as a catalyst. The detection method provided by the invention can be used for effectively detecting the content of the similar binary bromo-alcohol in the electronic waste recycled material, and the detection method is simple and rapid, low in detection limit, strong in matrix interference resistance, sensitive and accurate, and excellent in repeatability and reproducibility.

Description

Technical Field

[0001] This invention relates to the field of analytical chemistry, and in particular to a method for detecting the content of dibromool-like substances in electronic waste recycling. Background Technology

[0002] 2,2-Bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid are important dibromool-like plasticizers and flame retardants used in electronic products, with wide applications. Dibromool-like substances (such as organic compounds containing multiple bromine atoms and hydroxyl groups) play a crucial role in polymer synthesis and flame retardant applications. As core components of flame retardants, they decompose upon heating, releasing HBr gas, which covers the material surface, reducing oxygen concentration, and capturing free radicals (such as ·OH and ·O) in the combustion chain reaction, thus interrupting the combustion process. The dehydration of dibromool-like substances forms a char layer that isolates air, enhancing the material's fire resistance. They are also suitable for flame-retardant modification of plastics such as polystyrene (PS), polyolefins (PO), and ABS. They are commonly used in the manufacture of epoxy resins, polyurethanes, and ABS plastics for electronic device housings and circuit boards to improve the fire resistance of materials. They are also used in flexible materials such as PVC and rubber for wires and cables and electronic component encapsulation, combining flame-retardant and plasticizing functions. During the high-temperature processing of electronic products, dibromool-like substances are added to prevent material degradation. These brominated flame retardants are found in electronic waste recyclables (such as circuit boards and casings).

[0003] However, with the widespread use of dibromo alcohols such as 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, and the deepening of research on their toxicity, their harmful effects have gradually been discovered. Studies have found that dibromo alcohols can enter the human body through the respiratory tract, digestive tract, and skin, and the harm caused by trace amounts of dibromo alcohols in the population is already quite serious. Bromine-containing flame retardants have also been detected in sediments, and long-term exposure can threaten ecosystems. Dibromo alcohols can act on the chromosomes of cells, causing changes in the number or structure of chromosomes, thereby causing uncontrolled growth of some tissues and cells and the formation of tumors. At the same time, they also have neurotoxicity and potential carcinogenicity in humans. They also have long-term toxic effects on aquatic organisms, significantly weakening their reproductive capacity. When incinerating electronic waste, dibromo alcohols can also generate highly toxic substances such as dioxins.

[0004] Due to the urgent need for detection of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, and the current lack of an accurate, effective, low-limit-of-detection method for qualitative and quantitative analysis, providing an accurate, low-limit-of-detection method for the qualitative and quantitative analysis of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid has become a pressing issue. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The detection method provided by this invention can effectively detect the content of dibromool-like substances in electronic waste recyclables, and the method is simple, rapid, has a low detection limit, strong resistance to matrix interference, high sensitivity and accuracy, and excellent repeatability and reproducibility.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for detecting the content of dibromool-like substances in electronic waste recyclables, the method comprising the following steps:

[0008] (1) Mix the dibromo alcohol-like standard with a solvent to prepare a standard working solution; extract the dibromo alcohol-like substance from electronic waste recycling and prepare a sample solution to be tested.

[0009] (2) The standard working solution and the sample solution to be tested obtained in step (1) are subjected to ultra-high performance liquid chromatography-mass spectrometry detection and analysis, and the content of dibromo alcohol-like substances in electronic waste is calculated according to the standard curve;

[0010] The dibromo alcohols include 2,2-bis(bromomethyl)-1,3-propanediol and / or diisooctyl ester-2,3,4,5-tetrabromobenzoic acid.

[0011] The detection method provided by this invention extracts one or a combination of two of 2,2-bis(bromomethyl)-1,3-propanediol or diisooctyl ester-2,3,4,5-tetrabromobenzoic acid from electronic waste recyclables, and then detects them using ultra-high performance liquid chromatography-mass spectrometry. This method avoids the destruction and loss of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, thus improving the detection accuracy. Furthermore, this method is simple, rapid, highly resistant to matrix interference, highly sensitive, and has good repeatability and reproducibility.

[0012] Preferably, the concentration of 2,2-bis(bromomethyl)-1,3-propanediol in the standard working solution in step (1) is 0.02-10 mg / L (e.g., it can be 0.02 mg / L, 0.1 mg / L, 0.5 mg / L, 0.6 mg / L, 0.7 mg / L, 0.8 mg / L, 0.9 mg / L, 1 mg / L, 5 mg / L or 10 mg / L, etc.).

[0013] Preferably, the concentration of diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the standard working solution in step (1) is 0.5-50 mg / L (e.g., it can be 0.5 mg / L, 0.6 mg / L, 0.7 mg / L, 0.8 mg / L, 0.9 mg / L, 1 mg / L, 5 mg / L, 1 mg / L, 20 mg / L, 40 mg / L or 50 mg / L, etc.).

[0014] Preferably, the solvent in step (1) includes methanol and / or acetonitrile.

[0015] Preferably, the preparation of the sample solution to be tested in step (1) includes: mixing and extracting electronic waste recyclables and extractant, purifying the extract using a solid phase extraction column, concentrating and adjusting the volume of the purified extract to obtain the sample solution to be tested.

[0016] Preferably, the extractant comprises any one or a combination of two of hexane, dichloromethane, toluene, acetone, acetonitrile, or methanol, and more preferably a combination of acetone and toluene.

[0017] Preferably, the volume ratio of acetone to toluene is 1:(1-2), where "1-2" can be, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2, etc.

[0018] In this invention, since 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid are weakly polar compounds, according to the principle of like dissolves like, both weakly polar and non-polar solvents such as n-hexane, toluene, and acetone can be selected for extraction. Considering the extraction effect of non-polar solvents on 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid contained in electronic waste, polar solvents such as dichloromethane, acetonitrile, or methanol are selected as extractants.

[0019] As a preferred technical solution of the present invention, the combination of acetone and toluene in a volume ratio of 1:(1-2) can extract 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid from the sample to be tested as much as possible, thereby improving the detection accuracy. At the same time, the detection accuracy is further improved when the two are in a specific volume ratio, and the stability of the extraction is improved, making the extraction effect more similar each time, thereby improving the repeatability and reproducibility of the detection.

[0020] Preferably, the solid phase extraction column is filled with WAX and GCB packing in a mass ratio of (2-4):1 (e.g., 2:1, 2.5:1, 3:1, 3.5:1, 4:1, etc.), and more preferably with a mass ratio of (2.5-3.5):1.

[0021] In this invention, the WAX ​​packing material is a mixed weak anion exchange adsorbent with macroporous PS / DVB as the matrix and modified with tertiary amine groups. Its benzene rings exhibit strong hydrophobic interactions, and the tertiary amine groups provide weak anion exchange capacity. The GCB packing material is graphitized carbon black packing material, composed of non-porous sheet-like molecules, and possesses positive charge. It achieves compound separation through a dual mechanism of reverse phase separation and ion exchange.

[0022] Preferably, the solvent used for volume adjustment includes methanol and / or acetonitrile.

[0023] Preferably, the solid-liquid ratio of the electronic waste recyclable to the extractant is 1g:(10-50)mL, where "10-50" can be, for example, 10, 15, 20, 25, 30, 35, 40, 45 or 50.

[0024] Preferably, the extraction method includes Soxhlet extraction, and the Soxhlet extraction time is 8-16 hours (e.g., 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, or 16 hours), preferably 10-14 hours.

[0025] Preferably, the extraction process further includes a concentration process.

[0026] Preferably, the concentration process includes rotary evaporation concentration.

[0027] Preferably, the vacuum degree of the rotary evaporation concentration is 5-10 kPa, for example, it can be 5 kPa, 6 kPa, 7 kPa, 8 kPa, 9 kPa or 10 kPa; the temperature of the rotary evaporation concentration is 40-60℃, for example, it can be 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃ or 60℃.

[0028] In this invention, the concentration mainly involves concentrating organic solvents. 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid have very low water solubility. By retaining 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the organic phase as much as possible, the detection accuracy is improved.

[0029] Preferably, the process of concentrating the purified liquid further includes filtration to remove impurities.

[0030] Preferably, the concentration of 2,2-bis(bromomethyl)-1,3-propanediol in the sample solution to be tested in step (1) is 0.05-5 mg / L, for example, it can be 0.05 mg / L, 0.1 mg / L, 0.5 mg / L, 1 mg / L, 2 mg / L, 3 mg / L or 5 mg / L, etc.

[0031] Preferably, the concentration of diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample solution to be tested in step (1) is 1-40 mg / L, for example, it can be 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L, 30 mg / L or 40 mg / L, etc.

[0032] Preferably, the electronic waste recyclables in step (1) further include pretreatment before extraction, the pretreatment including:

[0033] 1) Perform preliminary sorting of electronic waste to remove metals and non-organic materials, obtaining organic materials;

[0034] 2) Cut the organic material into blocks, freeze it with liquid nitrogen, and then pulverize it into powder at -100°C or below.

[0035] Preferably, the size of the block in step 2) is 1-2 cm, for example, it can be 1 cm, 1.2 cm, 1.5 cm, 1.8 cm or 2 cm, etc.

[0036] Preferably, the liquid nitrogen freezing time in step 2) is 10-15 minutes, for example, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes or 15 minutes.

[0037] Preferably, the pulverizer used in step 2) has a rotation speed of 200-350 rpm, such as 200 rpm, 250 rpm, 300 rpm or 350 rpm, etc.; and a pulverization time of 5-10 minutes, such as 5 minutes, 7 minutes, 9 minutes or 10 minutes, etc.

[0038] Preferably, the packing material of the chromatographic column in the ultra-high performance liquid chromatography-mass spectrometry detection in step (2) includes any one of C18 (e.g., ACQUITY UPLC BEH C18), C8 (e.g., ACQUITY UPLC BEH Shield RP8) or phenyl (e.g., ACQUITY UPLC BEH Phenyl), preferably phenyl.

[0039] In this invention, the ultra-high performance liquid chromatography-mass spectrometry detection uses a phenyl-based chromatographic column, which has excellent retention and separation characteristics for 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, thereby making the final detection results more accurate.

[0040] Preferably, in step (2), the column length of the ultra-high performance liquid chromatography-mass spectrometry detection column is 50-150 mm (e.g., 50 mm, 75 mm, 100 mm or 150 mm, etc.), the inner diameter is 1.8-2.2 mm (e.g., 1.8 mm, 1.9 mm, 2 mm, 2.1 mm or 2.2 mm, etc.), and the particle size of the packing material is 1.5-2.0 μm (e.g., 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm or 2 μm, etc.).

[0041] Preferably, the column temperature of the chromatographic column in the ultra-high performance liquid chromatography-mass spectrometry detection in step (2) is 30-60℃ (e.g., it can be 30℃, 40℃, 45℃, 50℃, 55℃ or 60℃, etc.).

[0042] Preferably, in step (2), the mobile phase in the ultra-high performance liquid chromatography-mass spectrometry detection includes mobile phase A and mobile phase B. Mobile phase A is an aqueous solution of formic acid with a mass concentration of 0.05-0.2% (e.g., 0.05%, 0.1%, 0.15%, or 0.2%), and mobile phase B is methanol.

[0043] The method provided by this invention uses a mobile phase formulation that comprehensively considers the performance of the two types of dibromools in electronic waste recyclables. By utilizing the different polarities of different mobile phases, the separation of the two types of dibromools is ensured to be better. Mobile phase A is a 0.05% to 0.2% formic acid aqueous solution, and mobile phase B is methanol. This allows for more complete separation of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, thereby making the detection results more accurate.

[0044] Preferably, the elution method of the mobile phase in the ultra-high performance liquid chromatography-mass spectrometry detection is gradient elution.

[0045] Preferably, the gradient elution procedure includes: from 0 to 7 minutes, the volume fraction of mobile phase A is uniformly changed from 93-97% (e.g., 93%, 94%, 95%, 96%, or 97%) to 0-5% (e.g., 0%, 1%, 2%, 3%, 4%, or 5%), and the volume fraction of mobile phase B is uniformly changed from 3-7% (e.g., 3%, 4%, 5%, 6%, or 7%) to 95-100% (e.g., 95%, 96%, 97%, 98%, 99%, or 100%); from 7 to 11 minutes, the volume fraction of mobile phase A is maintained at 0-5% (e.g., 0%, 1%, 2%, 3%, 4%, or 5%), and the volume fraction of mobile phase B is maintained at 95-100% (e.g., 95%, 96%, 97%, 98%, 99%, or 100%). From 11 min to 11.1 min, the volume fraction of mobile phase A changes uniformly from 0-5% (e.g., 0%, 1%, 2%, 3%, 4%, or 5%) to 93-97% (e.g., 93%, 94%, 95%, 96%, or 97%), and the volume fraction of mobile phase B changes uniformly from 95-100% (e.g., 95%, 96%, 97%, 98%, 99%, or 100%) to 3-7% (e.g., 3%, 4%, 5%, 6%, or 7%). From 11.1 min to 15 min, the volume fraction of mobile phase A remains at 93-97% (e.g., 93%, 94%, 95%, 96%, or 97%), and the volume fraction of mobile phase B remains at 3-7% (e.g., 3%, 4%, 5%, 6%, or 7%).

[0046] In this invention, to save analysis time, improve separation efficiency, and effectively clean the chromatographic column at the end of each analysis, ensuring the column remains in optimal condition, a gradient elution method is employed in the ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) detection. The specific gradient elution program used in this invention can successfully separate 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in a short time, resulting in rapid and accurate analysis.

[0047] Preferably, the flow rate of the mobile phase in the ultra-high performance liquid chromatography-mass spectrometry detection in step (2) is 0.2-0.5 mL / min, for example, it can be 0.2 mL / min, 0.24 mL / min, 0.28 mL / min, 0.32 mL / min, 0.36 mL / min, 0.40 mL / min, 0.44 mL / min, 0.48 mL / min or 0.5 mL / min, etc.

[0048] Preferably, in step (2), the injection volume in the ultra-high performance liquid chromatography-mass spectrometry detection is 1-10 μL, for example, it can be 1 μL, 2 μL, 3 μL, 4 μL, 5 μL, 6 μL, 7 μL, 7.5 μL, 8 μL, 9 μL, 9.5 μL or 10 μL, etc.

[0049] Preferably, in step (2), the detection time in the ultra-high performance liquid chromatography-mass spectrometry detection is 1-15 min, for example, it can be 1 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 5 min, 6 min, 8 min, 10 min, 12 min or 15 min, etc.

[0050] Preferably, in step (2), the ionization source used in the ultra-high performance liquid chromatography-mass spectrometry detection includes any one of an electrospray ionization source, an electron bombardment source, or an atmospheric pressure chemical ionization source, preferably an electrospray ionization source.

[0051] Preferably, in step (2), the ultra-high performance liquid chromatography-mass spectrometry detection uses a positive ion scanning mode.

[0052] Preferably, in step (2), the ultra-high performance liquid chromatography-mass spectrometry detection uses multiple reaction detection mode (MRM).

[0053] Preferably, in step (2), the temperature of the drying gas of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 200-350℃, for example, it can be 200℃, 210℃, 230℃, 250℃, 280℃, 300℃, 320℃, 330℃, 340℃ or 350℃, etc.

[0054] Preferably, in step (2), the flow rate of the drying gas of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 3-14 L / min, for example, it can be 3 L / min, 5 L / min, 8 L / min, 10 L / min, 12 L / min or 14 L / min, etc.

[0055] Preferably, in step (2), the sheath gas temperature of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 150-300℃, for example, it can be 150℃, 160℃, 170℃, 190℃, 200℃, 220℃, 250℃, 260℃, 280℃, 290℃ or 300℃, etc.

[0056] Preferably, in step (2), the sheath flow rate of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 3-12 L / min, for example, it can be 3 L / min, 5 L / min, 8 L / min, 10 L / min or 12 L / min, etc.

[0057] Preferably, in step (2), the capillary voltage in the ultra-high performance liquid chromatography-mass spectrometry detection is 2000-4500kV, for example, it can be 2000V, 2400V, 2800V, 3000V, 3500V, 4000V or 4500V, etc.

[0058] Preferably, in step (2), the nebulizing gas pressure of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 25-45 psi, for example, it can be 25 psi, 30 psi, 35 psi, 40 psi or 45 psi, etc.

[0059] Preferably, in step (2), the nozzle voltage of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 500-2000V, for example, it can be 500V, 1000V, 1500V or 2000V.

[0060] In this invention, in step (2), the analytical parameters for 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the ultra-high performance liquid chromatography-mass spectrometry detection are as follows:

[0061]

[0062] * indicates a quantitative ion pair.

[0063] Compared with the prior art, the present invention has at least the following beneficial effects:

[0064] This invention provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The method involves extracting the target analytes from the sample and detecting them using ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), avoiding damage and loss to 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, thus improving detection accuracy. The method has low detection limits: 0.037 mg / kg for 2,2-bis(bromomethyl)-1,3-propanediol and 1.2 mg / kg for diisooctyl ester-2,3,4,5-tetrabromobenzoic acid. The method is simple, rapid, highly resistant to matrix interference, highly sensitive, and exhibits good repeatability and reproducibility. Attached Figure Description

[0065] Figure 1 The total ion chromatogram of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample solution to be tested in Example 1 is shown.

[0066] Figure 2 The mass spectrum of the sample solution to be tested in Example 1 in MRM mode is 2,2-bis(bromomethyl)-1,3-propanediol, where the selective ion pair is 262.9>67.0.

[0067] Figure 3 The mass spectrum of the sample solution to be tested in Example 1 in MRM mode is diisooctyl ester-2,3,4,5-tetrabromobenzoic acid, with the selective ion pair being 550.9 > 533.5. Detailed Implementation

[0068] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0069] The sources of each component in the following examples and test cases are shown below:

[0070] product factory Brand 2,2-bis(bromomethyl)-1,3-propanediol DR.E 1100551 Diisooctyl ester-2,3,4,5-tetrabromobenzoic acid BePure G0089240

[0071] Example 1

[0072] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The specific steps are as follows:

[0073] (I) Determination of standard working solutions

[0074] Preparation of standard working solutions: 2,2-bis(bromomethyl)-1,3-propanediol standard and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid standard were respectively mixed with methanol solvent to prepare a series of standard working solutions with 2,2-bis(bromomethyl)-1,3-propanediol concentrations of 0.02 mg / L, 0.05 mg / L, 0.1 mg / L, 0.5 mg / L, 1 mg / L, and 5 mg / L, and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid concentrations of 0.5 mg / L, 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L, and 50 mg / L.

[0075] The standard working solutions were analyzed by ultra-high performance liquid chromatography-mass spectrometry according to the instrument parameters described below to obtain the standard working curves;

[0076] The standard curve equation for 2,2-bis(bromomethyl)-1,3-propanediol is: y = 3867.51x + 156.8, R 2 =0.9995;

[0077] The standard curve equation for diisooctyl ester-2,3,4,5-tetrabromobenzoic acid is: y = 1762.36x + 162.2, R 2 =0.9992.

[0078] (II) Determination of the sample solution to be tested

[0079] 1) Sample preparation: The electronic waste was initially sorted to remove metals and non-organic materials, resulting in organic materials; the organic materials were cut into 1-2 cm pieces and placed in liquid nitrogen for 15 minutes to ensure that the samples were completely frozen; then they were pulverized at -100℃ with a pulverizer speed of 300 rpm for 10 minutes to obtain powdered samples.

[0080] 2) Extraction: Weigh 2.0029 g of the sample to be tested, place it in a round bottom flask, add 50 mL of extractant (volume ratio of 4:6 acetone and toluene), seal, and extract in a Soxhlet extractor for 12 h to obtain the extract;

[0081] 3) Concentration: Rotary evaporation is used to obtain the first concentrated liquid;

[0082] 4) Purification: The obtained concentrate is purified using an SPE column (the packing material is WAX packing and GCB packing with a mass ratio of 3:1) to obtain a purified solution.

[0083] 5) Concentration: After the purified solution is concentrated by nitrogen blowing, the concentrated solution is filtered and diluted to 2 mL with methanol to obtain the sample solution to be tested. At the same time, a blank experiment is performed (using the same method as above without adding the sample).

[0084] 6) Determination: Inject the sample solution and blank solution separately to obtain the detection results, and then calculate the content of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the electronic waste recycling. The total ion chromatogram of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid is shown in the figure below. Figure 1 As shown; the mass spectra of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid with selected quantitative ion pairs of 262.9>67.0 and 550.9>533.5 in MRM mode are shown below. Figure 2 and Figure 3 As shown.

[0085] (III) The instrument parameters are as follows:

[0086] The chromatographic conditions for liquid chromatography analysis are as follows:

[0087] ACQUITY UPLC BEH Phenyl column (particle size: phenyl, 2.1 mm × 50 mm, 1.7 μm); column temperature: 40 °C; injection volume: 5 μL; mobile phase A: 0.15% formic acid aqueous solution; mobile phase B: methanol; flow rate: 0.3 mL / min; elution program: from 0 to 7 min, the volume fraction of mobile phase A was uniformly changed from 95% to 0%, and the volume fraction of mobile phase B was uniformly changed from 5% to 100%; from 7 to 11 min, the volume fraction of mobile phase A was maintained at 0%, and the volume fraction of mobile phase B was maintained at 100%; from 11 to 11.1 min, the volume fraction of mobile phase A was uniformly changed from 0% to 95%, and the volume fraction of mobile phase B was uniformly changed from 100% to 5%; from 11.1 to 15 min, the volume fraction of mobile phase A was maintained at 95%, and the volume fraction of mobile phase B was maintained at 5%.

[0088] Mass spectrometry conditions: Electrospray ionization (ESI), positive ion scanning mode, ion source dryer temperature 200℃; dryer flow rate 8 L / min; ion source sheath gas temperature 250℃; sheath gas flow rate 11 L / min; nebulizer gas pressure 40 psi; capillary voltage 4000 V; ion source nozzle voltage 1500 V; multiple reaction monitoring (MRM) mode. Other mass spectrometry parameters are shown in Table 1, where * indicates quantitative ion pairs.

[0089] Table 1

[0090]

[0091] Selected ion pairs for 2,2-bis(bromomethyl)-1,3-propanediol: m / z = 262.9>81.0 and 262.9>67.0*, where 262.9>67.0* is the quantitative ion.

[0092] Selected ion pairs for diisooctyl ester-2,3,4,5-tetrabromobenzoic acid: 550.9>533.5* and 550.9>97.1, where 550.9>533.5* is the quantitative ion.

[0093] The contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid are calculated according to the following formula:

[0094]

[0095] In the formula:

[0096] X i —The content of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample, in mg / kg;

[0097] cis —The concentrations of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the standard working solution, in mg / L;

[0098] A—Peak intensities of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample solution to be tested;

[0099] A ib —Peak intensities of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in blank solution;

[0100] V—The final volume of the sample solution to be tested, in mL;

[0101] A is —Peak intensities of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the standard working solution;

[0102] m—sample mass, in grams;

[0103] The standard curve, combined with the test results, showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 166 μg / kg and 2.05 mg / kg, respectively.

[0104] Example 2

[0105] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that, in the determination of the sample solution, the extractant is acetone and toluene in a 1:1 volume ratio, totaling 50 mL, and the extraction time is 10 h; in the liquid chromatography analysis, mobile phase A is a 0.05% formic acid aqueous solution, and mobile phase B is methanol; the elution program includes: from 0 to 7 min, the volume fraction of mobile phase A changes uniformly from 93% to 0%, and the volume fraction of mobile phase B changes from... The volume fraction of mobile phase A was uniformly changed from 7% to 100%; from 7 min to 11 min, the volume fraction of mobile phase A was maintained at 0%, and the volume fraction of mobile phase B was maintained at 100%; from 11 min to 11.1 min, the volume fraction of mobile phase A was uniformly changed from 0% to 93%, and the volume fraction of mobile phase B was uniformly changed from 100% to 7%; from 11.1 min to 15 min, the volume fraction of mobile phase A was maintained at 93%, and the volume fraction of mobile phase B was maintained at 7%, and the remaining steps and parameters were the same as in Example 1.

[0106] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 153 μg / kg and 1.83 mg / kg, respectively.

[0107] Example 3

[0108] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that, in the determination of the sample solution, the extractant is acetone and toluene in a volume ratio of 1:2, totaling 50 mL, and the extraction time is 10 h; in the liquid chromatography analysis, mobile phase A is a 0.2% formic acid aqueous solution, and mobile phase B is methanol; the elution program includes: from 0 to 7 min, the volume fraction of mobile phase A changes uniformly from 97% to 5%, and the volume fraction of mobile phase B... The volume fraction of mobile phase A was uniformly increased from 3% to 95% from 7 min to 11 min; the volume fraction of mobile phase A was maintained at 5% and the volume fraction of mobile phase B was maintained at 95% from 11 min to 11.1 min; the volume fraction of mobile phase A was uniformly increased from 5% to 97% and the volume fraction of mobile phase B was uniformly increased from 95% to 3% from 11.1 min to 15 min; the volume fraction of mobile phase A was maintained at 95% and the volume fraction of mobile phase B was maintained at 3%; the remaining steps and parameters were the same as in Example 1.

[0109] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 151 μg / kg and 1.97 mg / kg, respectively.

[0110] Example 4

[0111] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that, when preparing the sample solution, the extractant is replaced by 50 mL of a mixture of acetone and toluene (volume ratio 4:6) with 50 mL of a mixture of methanol and toluene (volume ratio 4:6). All other steps and parameters are the same as in Example 1.

[0112] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 146 μg / kg and 1.56 mg / kg, respectively.

[0113] Example 5

[0114] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that, when preparing the sample solution, the extractant is replaced by 50 mL of a mixture of acetone and toluene (volume ratio of 4:6) with 50 mL of acetone. All other steps and parameters are the same as in Example 1.

[0115] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 155 μg / kg and 1.85 mg / kg, respectively.

[0116] Example 6

[0117] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that, when preparing the sample solution, the extractant is replaced with 50 mL of a mixture of acetone and toluene (volume ratio of 4:6) instead of 50 mL of toluene. All other steps and parameters are the same as in Example 1.

[0118] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 158 μg / kg and 1.86 mg / kg, respectively.

[0119] Example 7

[0120] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that, when preparing the sample solution, the extractant is replaced by 50 mL of a mixture of acetone and toluene (volume ratio 4:6) with 50 mL of a mixture of dichloromethane and n-hexane (volume ratio 4:6). All other steps and parameters are the same as in Example 1.

[0121] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 154 μg / kg and 1.86 mg / kg, respectively.

[0122] Example 8

[0123] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that the Soxhlet extraction time for preparing the sample solution is 8 hours, while the other steps and parameters are the same as in Example 1.

[0124] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 156 μg / kg and 1.86 mg / kg, respectively.

[0125] Example 9

[0126] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that the Soxhlet extraction time for preparing the sample solution is 16 hours, while the other steps and parameters are the same as in Example 1.

[0127] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 163 μg / kg and 2.03 mg / kg, respectively.

[0128] Example 10

[0129] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that the ACQUITY UPLC BEH Phenyl column (with phenyl packing material) is replaced with an ACQUITY UPLC BEH Shield RP8 column (with C8 packing material) in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0130] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 155 μg / kg and 1.85 mg / kg, respectively.

[0131] Example 11

[0132] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that the ACQUITY UPLC BEH Phenyl column (with phenyl packing material) is replaced with an ACQUITY UPLC BEH C18 column (with C18 packing material) in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0133] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 155 μg / kg and 1.86 mg / kg, respectively.

[0134] Example 12

[0135] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that the elution procedure during liquid chromatography analysis is as follows: from 0 to 7 min, the volume fraction of mobile phase A is uniformly changed from 95% to 0%, and the volume fraction of mobile phase B is uniformly changed from 5% to 50%; from 7 min to 11 min, the volume fraction of mobile phase A is maintained at 0%, and the volume fraction of mobile phase B is maintained at 50%; from 11 min to 11.1 min, the volume fraction of mobile phase A is uniformly changed from 0% to 95%, and the volume fraction of mobile phase B is uniformly changed from 50% to 5%; from 11.1 to 15 min, the volume fraction of mobile phase A is maintained at 95%, and the volume fraction of mobile phase B is maintained at 5%. The remaining steps and parameters are the same as in Example 1.

[0136] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 157 μg / kg and 1.87 mg / kg, respectively.

[0137] Example 13

[0138] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that the mobile phase A is water and the mobile phase B is methanol in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0139] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 152 μg / kg and 1.84 mg / kg, respectively.

[0140] Example 14

[0141] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that the mobile phase A is a 0.15% formic acid aqueous solution and the mobile phase B is acetonitrile in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0142] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 151 μg / kg and 1.83 mg / kg, respectively.

[0143] Example 15

[0144] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that the mobile phase A is a 0.15% aqueous acetic acid solution and the mobile phase B is methanol in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0145] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 157 μg / kg and 1.86 mg / kg, respectively.

[0146] Example 16

[0147] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that the mobile phase A is a 0.02% formic acid aqueous solution and the mobile phase B is methanol in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0148] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 155 μg / kg and 1.86 mg / kg, respectively.

[0149] Example 17

[0150] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that the mobile phase A is a 0.3% formic acid aqueous solution and the mobile phase B is methanol in the liquid chromatography analysis. The remaining steps and parameters are the same as in Example 1.

[0151] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 157 μg / kg and 1.85 mg / kg, respectively.

[0152] Example 18

[0153] This embodiment provides a method for detecting the content of dibromool-like substances in electronic waste recyclables. The only difference between this method and Example 1 is that in the determination of the sample solution, the SPE column is filled with WAX and GCB packing materials in a mass ratio of 4:1. The remaining steps and parameters are the same as in Example 1.

[0154] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 152 μg / kg and 189 mg / kg, respectively.

[0155] Comparative Example 1

[0156] This comparative example provides a method for detecting the content of dibromool-like substances in electronic waste recycling. The only difference between this method and Example 1 is that gas chromatography-mass spectrometry is used instead of ultra-high performance liquid chromatography-mass spectrometry. The remaining steps and parameters are the same as in Example 1.

[0157] The parameters are as follows:

[0158] The chromatographic conditions for gas chromatography analysis are as follows:

[0159] Agilent HP-5MS column (30m × 0.25mm, 0.25μm); Injector temperature: 250℃; Injection volume: 1μL; Column temperature: Initial temperature 100℃, hold for 0.5min, then increase to 280℃ at 20℃ / min, hold for 1min, then increase to 320℃ at 20℃ / min, hold for 5min; Carrier gas: Helium, constant flow rate 1mL / min; Injection mode: Splitless; Transfer line temperature: 280℃.

[0160] Detector conditions:

[0161] The detector is a mass spectrometer detector; ion source temperature: 230℃; electron ionization: 70eV; quadrupole temperature: 150℃; residence time: 50ms; scan range: 50m / z~1000m / z.

[0162] Calculations showed that the contents of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample were 147 μg / kg and 1.82 mg / kg, respectively.

[0163] Test Example 1

[0164] Repeatability test

[0165] The method for detecting the content of dibromool-like substances in electronic waste recyclables, as provided in Examples 1-18 and Comparative Example 1, was repeated 10 times, and the relative standard deviation A was calculated. The method was then repeated 10 times by 5 different laboratories, and the relative standard deviation B was calculated. The test results are shown in Table 2 below.

[0166] Table 2

[0167]

[0168]

[0169] The above data show that the detection method provided by the present invention has the advantages of good repeatability and reproducibility; the detection method provided by the present invention can accurately and effectively detect the content of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in electronic waste recycling.

[0170] Comparing Examples 1 and 4-7, it can be found that using the preferred extractant of the present invention when preparing the test sample solution results in better extraction effect and higher accuracy of the test sample; it improves the stability of extraction, thereby improving the stability of detection results, reducing errors, and improving repeatability and reproducibility.

[0171] Comparing Examples 1 and 8-9, it can be seen that the present invention further improves the extraction effect and detection accuracy by limiting the extraction parameters.

[0172] Comparing Examples 1 and 10-11, it can be seen that the choice of chromatographic column has a significant impact on the experimental results.

[0173] Comparing Examples 1 and 12, it can be seen that the volume fractions of mobile phase A and mobile phase B in the gradient elution process affect the repeatability of the detection results.

[0174] Comparing Examples 1 and 13-15, it can be seen that using a mobile phase outside the preferred scope of this application is not conducive to the separation of the two types of dibromool compounds.

[0175] Comparing Examples 1 and 16-17, it can be seen that the mass concentration of formic acid water in mobile phase A affects the detection results.

[0176] Comparing Examples 1 and 18, it can be seen that the SPE column with the preferred packing ratio of the present invention has good purification effect and good repeatability when the test sample solution is prepared.

[0177] Comparing Example 1 and Comparative Example 1, it can be found that the present invention, by employing ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS / MS), provides more accurate detection results for 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid compared to gas chromatography-mass spectrometry (GC-MS / MS).

[0178] Test Example 2

[0179] Recovery rate test

[0180] Test Method: 0.1 mL of standard working solutions (1 mg / L each) of 2.2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid were added dropwise to a 2.0 g sample of electronic waste (the electronic waste was pre-crushed at low temperature into the sample), making the spiked concentration in the sample 0.10 mg / L. After the solvent had completely evaporated, the target compound was adsorbed into the sample. Extraction and determination were performed according to the methods provided in Examples 1-18 and Comparative Example 1 for detecting the content of dibromool-like compounds in electronic waste. The recovery rate of the target compound was obtained by subtracting the sample concentration from the spiked concentration and comparing it with the theoretical concentration. Each test method was repeated three times, and the average value was taken. The test results are shown in Table 3 below.

[0181] Table 3

[0182]

[0183]

[0184] As shown in Table 3, the detection method provided by this invention has an excellent recovery rate, indicating that the detection method for 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in electronic waste provided by this invention has good precision and high accuracy.

[0185] Test Example 3

[0186] Method detection limit determination

[0187] Test method: Standard working solutions of 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid with concentrations of 0.020 mg / L and 1.0 mg / L, respectively, were detected according to the ultra-high performance liquid chromatography-mass spectrometry parameters provided in Example 1. The limits of detection for the target analytes were determined using a signal-to-noise ratio of 3:1. The limits of detection for 2,2-bis(bromomethyl)-1,3-propanediol and diisooctyl ester-2,3,4,5-tetrabromobenzoic acid were 0.037 mg / kg and 1.2 mg / kg, respectively. This indicates that the method provided by the present invention has low limits of detection for the target analytes.

[0188] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for detecting the content of dibromool-like substances in electronic waste recyclables, characterized in that, The method includes the following steps: (1) Mix the dibromo alcohol-like standard with a solvent to prepare a standard working solution; extract the dibromo alcohol-like substance from electronic waste recycling and prepare a sample solution to be tested. (2) The standard working solution and the sample solution to be tested obtained in step (1) are subjected to ultra-high performance liquid chromatography-mass spectrometry detection and analysis, and the content of dibromo alcohol-like substances in electronic waste is calculated according to the standard curve; The dibromo alcohols include 2,2-bis(bromomethyl)-1,3-propanediol and / or diisooctyl ester-2,3,4,5-tetrabromobenzoic acid.

2. The method according to claim 1, characterized in that, The concentration of 2,2-bis(bromomethyl)-1,3-propanediol in the standard working solution described in step (1) is 0.02-10 mg / L; Preferably, the concentration of diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the standard working solution in step (1) is 0.5-50 mg / L; Preferably, the solvent in step (1) includes methanol and / or acetonitrile.

3. The method according to claim 1 or 2, characterized in that, The preparation of the sample solution to be tested in step (1) includes: mixing electronic waste recyclables and extractant for extraction, purifying the extract using a solid phase extraction column, concentrating and adjusting the volume of the purified extract to obtain the sample solution to be tested; Preferably, the extractant comprises any one or a combination of two of hexane, dichloromethane, toluene, acetone, acetonitrile, or methanol, and more preferably a combination of acetone and toluene; Preferably, the volume ratio of acetone to toluene is 1:(1-2); Preferably, the solid phase extraction column is packed with WAX packing and GCB packing in a mass ratio of (2-4):1, and more preferably with a mass ratio of (2.5-3.5):

1. Preferably, the solvent used for volume adjustment includes methanol and / or acetonitrile; Preferably, the solid-liquid ratio of the electronic waste recyclable to the extractant is 1g:(10-50)mL; Preferably, the extraction method includes Soxhlet extraction, and the Soxhlet extraction time is 8-16 hours, preferably 10-14 hours.

4. The method according to any one of claims 1-3, characterized in that, The concentration of 2,2-bis(bromomethyl)-1,3-propanediol in the sample solution to be tested in step (1) is 0.05-5 mg / L; Preferably, the concentration of diisooctyl ester-2,3,4,5-tetrabromobenzoic acid in the sample solution to be tested in step (1) is 1-40 mg / L.

5. The method according to any one of claims 1-4, characterized in that, The electronic waste recyclables in step (1) also include pretreatment before extraction, the pretreatment including: 1) Perform preliminary sorting of electronic waste to remove metals and non-organic materials, obtaining organic materials; 2) Cut the organic material into blocks, freeze it with liquid nitrogen, and then pulverize it into powder at -100°C or below.

6. The method according to any one of claims 1-5, characterized in that, In step (2), the packing material of the chromatographic column used in the ultra-high performance liquid chromatography-mass spectrometry detection includes any one of C18, C8, or phenyl, preferably phenyl; Preferably, in step (2), the column length of the ultra-high performance liquid chromatography-mass spectrometry detection column is 50-150 mm, the inner diameter is 1.8-2.2 mm, and the particle size of the packing material is 1.5-2.0 μm; Preferably, the column temperature of the chromatographic column in the ultra-high performance liquid chromatography-mass spectrometry detection in step (2) is 30-60℃.

7. The method according to any one of claims 1-6, characterized in that, In step (2), the mobile phase in the ultra-high performance liquid chromatography-mass spectrometry detection includes mobile phase A and mobile phase B. Mobile phase A is an aqueous solution of formic acid with a mass concentration of 0.05-0.2%, and mobile phase B is methanol. Preferably, the elution method of the mobile phase in the ultra-high performance liquid chromatography-mass spectrometry detection is gradient elution; Preferably, the gradient elution procedure includes: from 0 to 7 minutes, the volume fraction of mobile phase A is uniformly changed from 93-97% to 0-5%, and the volume fraction of mobile phase B is uniformly changed from 3-7% to 95-100%; from 7 minutes to 11 minutes, the volume fraction of mobile phase A is maintained at 0-5%, and the volume fraction of mobile phase B is maintained at 95-100%; from 11 minutes to 11.1 minutes, the volume fraction of mobile phase A is uniformly changed from 0-5% to 93-97%, and the volume fraction of mobile phase B is uniformly changed from 95-100% to 3-7%; from 11.1 minutes to 15 minutes, the volume fraction of mobile phase A is maintained at 93-97%, and the volume fraction of mobile phase B is maintained at 3-7%.

8. The method according to any one of claims 1-7, characterized in that, In step (2), the flow rate of the mobile phase in the ultra-high performance liquid chromatography-mass spectrometry detection is 0.2-0.5 mL / min; Preferably, in step (2), the injection volume in the ultra-high performance liquid chromatography-mass spectrometry detection is 1-10 μL.

9. The method according to any one of claims 1-8, characterized in that, In step (2), the ionization source used in the ultra-high performance liquid chromatography-mass spectrometry detection includes any one of electrospray ionization source, electron impact source or atmospheric pressure chemical ionization source, preferably electrospray ionization source; Preferably, in step (2), the ultra-high performance liquid chromatography-mass spectrometry detection uses a positive ion scanning mode; Preferably, in step (2), the ultra-high performance liquid chromatography-mass spectrometry detection adopts multiple reaction detection mode.

10. The method according to any one of claims 1-9, characterized in that, In step (2), the temperature of the drying gas of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 200-350℃; Preferably, in step (2), the sheath gas temperature of the ion source in the ultra-high performance liquid chromatography-mass spectrometry detection is 150-300℃.

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