Method for detecting tetrabromobisphenol a and its ten common derivatives in sludge

Abstract

The application provides a pretreatment and detection method of tetrabromobisphenol A and ten common derivatives thereof in sludge, which comprises the following steps: (1) sample pretreatment: after mixing the frozen and dried sludge sample and the isotopic internal standard, oscillation extraction is carried out, and the extraction liquid is obtained after centrifugation by a centrifuge; the extraction liquid is purified by solid phase extraction to obtain a sample to be detected; (2) the sample to be detected obtained in the step (1) is detected by high performance liquid chromatography-tandem mass spectrometry; (3) the content of tetrabromobisphenol A and ten common derivatives thereof in the sample is calculated according to the internal standard method. The application provides a rapid and sensitive analysis and quantitative method of tetrabromobisphenol A and ten common derivatives thereof in sludge samples.

Description

Technical Field

[0001] This invention relates to the field of environmental pollutant detection, and to an analytical method for detecting tetrabromobisphenol A and ten common derivatives of it in sludge. Background Technology

[0002] Tetrabromobisphenol A (TBBPA), currently the most widely used brominated flame retardant, is extensively used in electronic products and building materials. 18% of TBBPA's annual production is used to produce various derivatives, including TBBPA bis(allyl ether) (TBBPA-BAE), TBBPA bis(2,3-dibromopropyl ether) (TBBPA-BDBPE), TBBPA bis(glycidyl ether) (TBBPA-BGE), and TBBPA bis(2-hydroxyethyl ether) (TBBPA-BHEE). During production and use, these bilaterally substituted TBBPA derivatives enter the environment. Correspondingly, unilaterally substituted derivatives have also been detected in the environment as byproducts or environmental transformation products. TBBPA bis(methyl ether) (TBBPA-BME) and TBBPA mono(methyl ether) (TBBPA-MME), as important biological and non-biological transformation products of TBBPA, are also TBBPA derivatives of considerable interest.

[0003] In wastewater treatment plants, TBBPA and its derivatives may originate from urban or agricultural runoff or be discharged into sewer systems, as well as from wet and dry deposition in the atmosphere, or industrial emissions. A portion of the highly lipophilic TBBPA and its derivatives in wastewater is concentrated in sludge; therefore, sludge is also an important sink for these emerging pollutants. Furthermore, during the resource utilization of sludge, the TBBPA and its derivatives contained within it may pose potential threats to ecological security and human health through various pathways.

[0004] Existing technologies have studied the occurrence of TBBPA and its derivatives in the environment, but current detection methods have the following problems: Current methods detect few target compounds, mostly focusing on a single TBBPA derivative in the sample, and cannot simultaneously detect multiple TBBPA derivatives; some TBBPA derivatives have large molecular weights, making them difficult to ionize using common electron impact ionization and chemical ionization sources in gas chromatography-mass spectrometry (GC-MS), and they undergo significant thermal decomposition during GC separation. They are also difficult to ionize using common electrospray ionization sources in liquid chromatography-mass spectrometry (LC-MS), and have high detection limits in liquid chromatography diode array detectors, failing to meet the requirements for detecting TBBPA derivatives in environmental samples. Therefore, an instrumental detection method capable of simultaneously detecting TBBPA and ten common derivatives is needed, meeting environmental detection requirements. Furthermore, due to the complexity of sludge media, establishing a simple and highly recoverable pretreatment method is also essential. Summary of the Invention

[0005] This application provides an analytical detection method for TBBPA and ten common derivatives in sludge. Addressing the shortcomings or improvement needs of existing technologies, the method aims to extract TBBPA and its ten common derivatives from the sample using an efficient, simple, and stable pretreatment method. Furthermore, it utilizes high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) and an atmospheric pressure chemical ionization source to rapidly and accurately detect the content of TBBPA and its ten common derivatives in the sludge sample. This solves the technical problems of complex pretreatment and high detection limits in the analysis and detection of TBBPA and its ten common derivatives.

[0006] To achieve the above objectives, according to one aspect of the present invention, an analytical detection method for tetrabromobisphenol A and ten common derivatives of it in sludge is provided, comprising the following steps:

[0007] (1) Sample pretreatment: After collecting the sludge samples, wrap them in aluminum foil and freeze them. Before analysis, freeze-dry them using a freeze dryer. After adding the internal standard, extract the samples by shaking and grinding. After centrifugation, collect the supernatant. Specifically, this includes:

[0008] (1-1) The sludge samples were wrapped in aluminum foil and frozen in a -20°C freezer. Before analysis, they were freeze-dried for 7 days.

[0009] (1-2) Weigh approximately 0.5 g of the sludge sample obtained in step (1-1) and add it to a 2 mL centrifuge tube. Simultaneously, add a 4 mm steel ball and a stable isotope-labeled TBBPA (…). 13 C 12 -TBBPA) and dimethylated TBBPA ( 13 C 12-TBBPA-BME), add a mixed solution of n-hexane and dichloromethane, and extract by high-speed oscillation and grinding using a tissue homogenizer. Collect the supernatant to obtain the primary extract.

[0010] (1-3) Extract the initial extract obtained in step (1-2) using a solid phase extraction column. Activate the solid phase extraction column with dichloromethane (DCM) and n-hexane (HEX), respectively. After loading the sample, elute with a mixed solution of n-hexane and dichloromethane.

[0011] (1-4) After the eluent obtained in step (1-3) is nearly dried by nitrogen blowing, the solvent is replaced with methanol in the injection vial;

[0012] (2) TBBPA and its ten common derivatives in the sample were quantitatively analyzed by using a high performance liquid chromatograph coupled with a triple quadrupole system. The mobile phase of the liquid chromatography was pure water and methanol, and gradient elution was used. The ion source of the mass spectrometer was an atmospheric pressure chemical ionization source, and multiple reaction monitoring mode and negative ion mode were used.

[0013] (3) Calculate the concentration of TBBPA and its ten common derivatives in sludge using the internal standard method.

[0014] Furthermore, the two isotope internal standards in steps (1-2) are: 13 C 12 -TBBPA and 13 C 12 -TBBPA-BME.

[0015] Furthermore, in step (1-2), the extract is a mixed solution of n-hexane and dichloromethane in a volume ratio of 1:1.

[0016] Furthermore, the eluent in steps (1-3) is a mixed solution of n-hexane and dichloromethane in a volume ratio of 1:1.

[0017] Furthermore, the high-performance liquid chromatography conditions in step (2) are as follows:

[0018] Elution procedure: The initial aqueous phase to organic phase ratio is 80:20, maintained for 1 min; then changed to 20:80 within 4 min; the ratio gradually changed to 100% organic phase within 15 min and maintained for 5 min; then returned to the initial ratio (80:20) within 1 min.

[0019] The injection volume was 10 μL; the column oven temperature was 20 °C; and the mobile phase flow rate was 0.3 mL / min. -1 .

[0020] Furthermore, the mass spectrometer conditions in step (2) are as follows:

[0021] Spray voltage: -4500V; Mass spectrometry scanning mode: Multiple reaction ion detection (MRM); Ion source temperature: 300℃.

[0022] Furthermore, in step (3), a concentration gradient of 1, 2, 5, 10, 20, 50, 100, 200, and 500 ng·g is used. -1 A standard curve was plotted using a mixture of TBBPA and ten common derivatives.

[0023] Concentration gradients of 10, 20, 50, 100, and 200 ng·g -1 of 13 C 12 -TBBPA-BME and 13 C 12 - Plot a standard curve using TBBPA standards. Among them, 13 C 12 -TBBPA was used to correct the recovery rates of TBBPA and five common unilaterally substituted derivatives; 13 C 12 -TBBPA-BME is used to correct the recovery rates of five common bilaterally substituted derivatives of TBBPA.

[0024] Compared with existing technologies, the advantages and beneficial effects of this method are as follows: it optimizes the use of the solid-phase extraction column, removes potentially highly polar matrices from the extract, simplifies operation, and achieves high recoveries of TBBPA and its ten common derivatives; it optimizes the ionization of TBBPA and its ten common derivatives using an atmospheric pressure chemical ionization source, significantly lowering the instrument detection limit; it improves the gradient elution method of high-performance liquid chromatography, achieving baseline separation of TBBPA and its ten common derivatives; it uses oscillating extraction for sludge extraction, which is simple to operate, avoids high-temperature processes, and prevents possible transformation of TBBPA and its ten common derivatives during pretreatment; and the established method is applicable to the determination of the content of TBBPA and its ten common derivatives in sludge samples. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart of the application process;

[0027] Figure 2 The recovery rate of the analytical detection method for TBBPA and ten common derivatives in this application;

[0028] Figure 3 This refers to the concentration of TBBPA and its ten common derivatives in the sludge of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Table 1. Structural formulas of TBBPA and ten common derivatives

[0031]

[0032] The analytical detection method for TBBPA and its ten common derivatives in sludge provided in this application includes the following steps:

[0033] (1) Sample pretreatment: Sludge samples obtained from the sludge treatment plant were wrapped in aluminum foil and frozen in a -20℃ freezer. Before analysis, they were freeze-dried for 7 days using a freeze dryer.

[0034] (2) Weigh 0.5g of the sludge sample obtained in step (1), add it to a 2mL centrifuge tube, and add a 4mm steel ball at the same time. Add 56.4ng of [unspecified ingredient] to each tube. 13 C 12 -TBBPA and 58.4ng 13 C 12 -TBBPA-BME was used to calibrate the recovery rates of TBBPA and five common single-sided substituted derivatives and five common double-sided substituted derivatives, respectively; a mixed solution of n-hexane and dichloromethane was added as the extraction solution, and after high-speed oscillation extraction using a tissue homogenizer, the mixture was centrifuged; the supernatant was collected as the initial extract;

[0035] (3) The initial extract obtained in step (2) is processed using ENVI-Carb. TM The solid-phase extraction (SPE) column was purified by activating it with dichloromethane and n-hexane, respectively. After loading the sample, it was eluted with a mixed solution of n-hexane and dichloromethane. The eluent was collected, purged to near dryness with nitrogen, and then reconstituted with methanol into a vial.

[0036] (4) The samples in the vials obtained in (3) were analyzed using a high performance liquid chromatography-mass spectrometry system, and the contents of TBBPA and its ten common derivatives in the sludge samples were calculated according to the internal standard method.

[0037] Instrument model: An Agilent 1290 Infinity II high-performance liquid chromatograph coupled with an Agilent 6460 triple quadrupole was used, and a MassHunter 10.0b workstation was used for data analysis.

[0038] Chromatographic conditions: The liquid chromatography column used was an Inertsil ODS-4 column (3 mm × 150 mm × 2 μm) manufactured by GL Science; the column oven temperature was set to 20 °C; and the mobile phase flow rate was 0.3 mL / min. -1 The injection volume was 10 μL; the mobile phase was ultrapure water (phase A) and methanol (phase B); gradient elution was used: the initial ratio of phase A to phase B was 80:20, maintained for 1 min; it changed to 20:80 within 4 min; the ratio gradually changed to 100% phase B within 15 min and was maintained for 5 min; then it was restored to the initial ratio (80:20) within one minute.

[0039] Mass spectrometry conditions: Atmospheric pressure chemical ionization source with negative ion detection mode; multiple reaction monitoring (MRM) mode for quantitative analysis.

[0040] Table 2. MRM parameters of TBBPA and ten common derivatives in Agilent 6460 triple quadrupole.

[0041]

[0042] (5) Plotting the standard curve

[0043] Standard curves were obtained using a mixture of standards for TBBPA and ten common derivatives, with concentration gradients of 1, 2, 5, 10, 20, 50, 100, 200, and 500 ng·g. -1 The linear correlation coefficients of the obtained standard curves were all greater than 0.99;

[0044] Table 3 Standard curves and correlation coefficients of TBBPA and its ten common derivatives

[0045]

[0046]

[0047] (6) Recovery rate determination

[0048] A certain mass of TBBPA and ten common derivative standards were added to the sludge sample, and a control sludge sample was set up to determine the background value of the sludge sample. The blank sample was pretreated according to the pretreatment method described in steps (2) and (3). The mass after pretreatment was calculated according to the standard curve drawn in step (5), and the recovery rate was calculated by comparing it with the added mass. The method recovery rate was calculated as follows:

[0049] R = (A - A0) / A1 × 100%

[0050] A - Content of TBBPA and its ten common derivatives obtained from the standard curve;

[0051] Background content of TBBP and its ten common derivatives in A0-sludge samples;

[0052] A1 - The content of added TBBPA and its ten common derivatives;

[0053] R - Recovery rate (%).

[0054] The spike recovery rate of this pretreatment method is determined by Figure 2 The demonstration is set up with 5 parallels, and the precision is expressed as relative standard deviation (RSD).

[0055] (7) Instrument detection limit and method quantitation limit

[0056] Table 4. Instrument detection limits and method quantitation limits for TBBPA and its ten common derivatives.

[0057]

[0058]

[0059] (8) Determination of TBBPA and its ten common derivatives in sludge

[0060] All sludge concentrations were calculated based on dry weight, and each sample concentration was calibrated using a recovery standard. The above steps were followed to analyze effluent sludge from a wastewater treatment plant in Beijing. A process blank was added during the processing of each batch of samples. No TBBPA or its ten common derivatives contamination due to operational factors was found in the process blanks. A solvent blank (methanol) was added every four injections during the injection process, and no compound residues were found on the column.

[0061] Concentrations of TBBPA and its ten common derivatives in sludge Figure 3 The text indicates that n1, n2, n3, and n4 represent wastewater sludge leaving the wastewater treatment plant during different time periods. Except for TBBPA-BDBPE and TBBPA-BHEE, which were not detected in some samples, TBBPA and its common derivatives were detected in all four sludge samples.

[0062] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for the analysis and detection of tetrabromobisphenol A and ten common derivatives of it in sludge, characterized in that, Includes the following steps: (1) Sample pretreatment: After collecting the sludge samples, wrap them in aluminum foil and freeze them. Before analysis, freeze-dry them using a freeze dryer. After adding the internal standard, extract the samples by shaking and grinding. After centrifugation, collect the supernatant. Specifically, this includes: (1-1) The sludge samples were wrapped in aluminum foil and frozen in a -20°C freezer. Before analysis, they were freeze-dried for 7 days. (1-2) Weigh approximately 0.5 g of the sludge sample obtained in step (1-1) and add it to a 2 mL centrifuge tube. Simultaneously, add a 4 mm steel ball and a stable isotope-labeled... 13 C 12 -TBBPA and dimethylation 13 C 12 -TBBPA-BME was added to a mixed solution of n-hexane and dichloromethane, and extracted by high-speed oscillation and grinding using a tissue homogenizer. The supernatant was collected to obtain the primary extract. (1-3) Extract the initial extract obtained in step (1-2) using a solid-phase extraction column, and activate ENVI-Carb with dichloromethane (DCM) and n-hexane (HEX), respectively. TM Solid-phase extraction column, after sample loading, eluted with a mixed solution of n-hexane and dichloromethane; (1-4) After the eluent obtained in step (1-3) is nearly dried by nitrogen blowing, the solvent is replaced with methanol in the injection vial; (2) TBBPA and its ten common derivatives in the sample were quantitatively analyzed by a high performance liquid chromatography (HPLC) system coupled with a triple quadrupole system. The mobile phase of HPLC was pure water and methanol, and gradient elution was used. The ion source of mass spectrometry was an atmospheric pressure chemical ionization source, and multiple reaction monitoring mode and negative ion mode were used. Chromatographic conditions: The HPLC column was an Inertsil ODS-4 HPLC column manufactured by JIER Technology Co., Ltd., with a thickness of 3 mm × 150 mm × 2 μm. (3) Calculate the concentration of TBBPA and its ten common derivatives in sludge using the internal standard method; The two isotope internal standards in step (1-2) are: 13 C 12 -TBBPA and 13 C 12 -TBBPA-BME; In steps (1-2), the extract is a mixed solution of n-hexane and dichloromethane in a volume ratio of 1:

1. The eluent in steps (1-3) is a mixed solution of n-hexane and dichloromethane in a volume ratio of 1:

1. The tetrabromobisphenol A and its ten common derivatives are shown in the table below:

2. The analytical detection method for tetrabromobisphenol A and its ten common derivatives in sludge as described in claim 1, characterized in that, The high-performance liquid chromatography conditions in step (2) are as follows: Elution procedure: The initial aqueous phase to organic phase ratio is 80:20, maintained for 1 min; then changed to 20:80 within 4 min; the ratio gradually changed to 100% organic phase within 15 min and maintained for 5 min; then returned to the initial ratio of 80:20 within 1 min. The injection volume was 10 μL; the column oven temperature was 20 °C; and the mobile phase flow rate was 0.3 mL / min. -1 .

3. The analytical detection method for tetrabromobisphenol A and its ten common derivatives in sludge as described in claim 1, characterized in that, The mass spectrometer conditions in step (2) are as follows: Spray voltage: -4500V; Mass spectrometry scanning mode: Multiple reaction ion detection (MRM); Ion source temperature: 300℃.

4. The analytical detection method for tetrabromobisphenol A and its ten common derivatives in sludge as described in claim 1, characterized in that, In step (3), a concentration gradient of 1, 2, 5, 10, 20, 50, 100, 200, and 500 ng·g is used. -1 A standard curve was plotted using a mixture of standards.

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