Method for determining dichloropropanol in solid waste

Abstract

The present application relates to a kind of determination method of dichloropropanol in solid waste, belong to analytical chemistry technical field.The determination method of dichloropropanol in solid waste provided by the present application includes the following steps: (1) the solid waste to be measured, matrix modifier, isotopic internal standard solution, N-propyl ethylenediamine solid adsorbent, reduced graphene oxide and lipophilic synthetic hectorite are added into headspace bottle, oscillation, ultrasonic, centrifugal, and the sample to be measured is obtained;(2) the sample to be measured obtained in step (1) is placed in automatic headspace sampler, after equilibrium in automatic headspace sampler, dichloropropanol in gas phase is detected by gas chromatography and mass spectrometry.The determination method of the present application carries out pretreatment to the solid waste to be measured, can effectively avoid the interference of impurities in solid waste to the determination of dichloropropanol, gas chromatography and mass spectrometry are used to determine dichloropropanol, qualitative by comparing with standard substance retention time and mass spectrum, internal standard method is quantified.

Description

Technical Field

[0001] This invention belongs to the field of analytical chemistry technology, specifically relating to a method for determining dichloropropanol in solid waste. Background Technology

[0002] Dichloropropanol, including 1,3-dichloro-2-propanol (1,3-DCP) and 2,3-dichloro-1-propanol (2,3-DCP), is an important intermediate in the preparation of epichlorohydrin and a recognized contaminant generated during food processing. It is soluble in most organic solvents such as ethanol and ether. Dichloropropanol is mainly used as a solvent in the organic synthesis of the antiviral drug ganciclovir. It is also a solvent for cellulose acetate and ethyl cellulose, and is used in the manufacture of epoxy resins and ion exchange resins. It exhibits reproductive toxicity, neurotoxicity, genotoxicity, and carcinogenicity. Therefore, the detection of dichloropropanol in the environment is crucial.

[0003] Currently, the detection of dichloropropanol mainly focuses on seasonings in food and indoor air in workplaces. Gas chromatography, liquid chromatography, and gas chromatography-mass spectrometry are the primary methods used for analysis. These methods involve solid-phase extraction followed by derivatization before determination, using derivatizing agents such as phenylboronic acid (PBA), N-perfluorobutyrylimidazolium (HFBI), and perfluorobutyric anhydride (HFBA). While these methods provide good quantitative results for samples with a single media composition, they suffer from drawbacks in analyzing complex samples such as solid waste containing numerous impurities and interfering substances (e.g., pigments, organic acids, proteins, metal ions, thioesters, etc.). These drawbacks include poor derivative stability, the introduction of byproducts during derivatization that interfere with the target compound, and difficulty in controlling recovery rates. Even selected ion detection (SIM) methods struggle to eliminate interference, affecting accuracy and potentially leading to false positives, thus increasing detection costs.

[0004] Therefore, it is very important to develop a method for the determination of dichloropropanol in solid waste. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide a method for determining dichloropropanol in solid waste.

[0006] This invention is achieved through the following technical solution:

[0007] This invention provides a method for determining dichloropropanol in solid waste, comprising the following steps:

[0008] (1) Add the solid waste to be tested, matrix modifier, isotope internal standard solution, N-propylethylenediamine solid adsorbent, reduced graphene oxide and lipophilic synthetic lithium montmorillonite into a headspace vial, shake, sonicate, and centrifuge to obtain the sample to be tested.

[0009] (2) Place the sample to be tested obtained in step (1) into an automatic headspace sampler. After equilibration in the automatic headspace sampler, detect the dichloropropanol in the gas phase by gas chromatography and mass spectrometry.

[0010] This invention provides a headspace gas chromatography-mass spectrometry (GC-MS) method for the qualitative and quantitative analysis of dichloropropanol in solid waste. This method can be used for the qualitative and quantitative analysis of solid waste with different matrix types. The method employs a matrix modifier, an isotope internal standard, N-propylethylenediamine (PSA) solid adsorbent, reduced graphene oxide, and lipophilic synthetic lithium montmorillonite for pretreatment of the solid waste. This effectively avoids interference from impurities in the solid waste on the determination of dichloropropanol. Gas chromatography and mass spectrometry are used to determine dichloropropanol. Qualitative analysis is performed by comparing the retention time and mass spectrum with that of a standard, while quantification is achieved using the internal standard method. This method is simple, easy to operate, solvent-saving, and offers high accuracy and precision. It is rapid and convenient, suitable for the identification and analysis of large quantities of solid waste.

[0011] Preferably, in step (1), the matrix modifier is a saturated sodium sulfate solution.

[0012] The addition of a matrix modifier in this invention can eliminate or reduce the influence of matrix effects, and can improve the partition coefficient of the analyte dichloropropanol in the gas-liquid two-phase system, thereby improving the sensitivity of the analysis.

[0013] Preferably, in step (1), the isotope internal standard solution includes a 1,3-dichloro-2-propanol-D5 solution and a 2,3-dichloro-1-propanol-D5 solution, wherein the concentrations of the 1,3-dichloro-2-propanol-D5 solution and the 2,3-dichloro-1-propanol-D5 solution are 5 μg / mL to 100 μg / mL; more preferably, the concentrations of the 1,3-dichloro-2-propanol-D5 solution and the 2,3-dichloro-1-propanol-D5 solution are 100 μg / mL.

[0014] Preferably, in step (1), the mass ratio of the N-propylethylenediamine solid adsorbent, the reduced graphene oxide, and the lipophilic synthetic lithium montmorillonite is 1:1:15.

[0015] In this invention, the addition of solid-phase adsorbent PSA can chelate with metal ions, removing organic acids and metal ions from the solid waste to be tested. The addition of reduced graphene oxide can remove pigments and oxidized substances from the solid waste. Lipophilic synthetic lithium montmorillonite has good adsorption properties, enabling inorganic ions and organic molecules on the surface of the dispersion to be stably dispersed through electron cloud interactions. It can adsorb cations, making them electrically neutral, and can remove lipid pigments and proteins, as well as disperse sample solutions, which is beneficial for the extraction of the target analyte dichloropropanol.

[0016] Preferably, in step (1), the mass ratio of the solid waste to be tested to the N-propylethylenediamine solid adsorbent is 200:1.

[0017] Preferably, in step (1), the mass-to-volume ratio of the solid waste to be tested to the matrix modifier and the isotope internal standard solution is 2:10:0.005, g / mL.

[0018] Preferably, in step (2), the gas chromatography column used is a highly polar column; more preferably, the column is a DB-FFAP column, 30m×0.25mm×0.25μm.

[0019] Preferably, in step (2), the equilibrium temperature is 90°C and the time is not less than 30 minutes.

[0020] More preferably, the balancing time is 30 minutes.

[0021] The equilibrium temperature of a sample is directly related to its vapor pressure, which affects the partition coefficient. Higher temperatures result in higher vapor pressures, higher headspace gas concentrations, and higher analytical sensitivity. However, as the equilibrium temperature increases, the moisture content in the gas phase also rises sharply. Moisture in the sample can affect column life and mass spectrometry sensitivity. Studies have shown that a 90°C equilibrium temperature provides better detection performance.

[0022] The equilibration time is related to the molecular size of dichloropropanol, the viscosity of the medium, and the temperature. This study found that the peak area response of dichloropropanol did not change significantly after an equilibration time of 30 minutes. Therefore, a equilibration time of at least 30 minutes is sufficient for effective detection of dichloropropanol. Considering both energy conservation and improved sample analysis efficiency, the optimal equilibration time is 30 minutes.

[0023] Preferably, in step (2), the conditions of the automatic headspace sampler are: equilibrium temperature 90℃; equilibrium time 30min; sampling needle temperature 105℃; transmission line temperature 110℃; pressure equilibrium time 1min; injection time 0.2min; needle withdrawal time 0.4min.

[0024] Preferably, in step (2), the gas chromatography conditions are as follows: injection port temperature: 250℃; split ratio: 5:1; column: DB-FFAP 30 m × 0.25 mm × 0.25 μm; column flow rate: 1.0 mL / min; temperature program: 60℃ for 2 min, then increase to 160℃ at a rate of 8℃ / min and hold for 2 min.

[0025] Preferably, in step (2), the conditions for mass spectrometry are: transfer line temperature: 260℃; ion source temperature: 230℃; MS quadrupole: 150℃; mass spectrometry bombardment electron energy: 70eV.

[0026] Preferably, the detection limit for 1,3-dichloro-2-propanol and the detection limit for 2,3-dichloro-1-propanol in the method for determining dichloropropanol in solid waste are 1.4 μg / kg and 2.7 μg / kg, respectively.

[0027] The present invention has the following beneficial effects:

[0028] (1) This invention provides a method for determining dichloropropanol in solid waste, which reduces pretreatment steps and reagent usage, and is a green technology suitable for processing complex solid waste samples. Compared with traditional derivatization methods, this method achieves energy saving and efficiency improvement, contributes to sustainable development, reduces the consumption of natural resources, and is environmentally friendly. On the one hand, it improves the accuracy of test results, and on the other hand, it improves analytical efficiency and reduces testing costs, providing technical support for the identification of dichloropropanol in solid waste.

[0029] (2) In the analysis of spiked samples at three concentration levels of typical solid waste types—ash and biochemical sludge—using the method of this invention, the relative standard deviation for biochemical sludge samples was 1.8%–6.1%; the relative standard deviation for industrial ash samples was 2.8%–6.8%; the spiked recovery rate for biochemical sludge samples was 86%–102%; and the spiked recovery rate for industrial ash samples was 89%–104%. The method of this invention exhibits good recovery efficiency for dichloropropanol and achieves good accuracy and precision for samples of different solid waste types. Attached Figure Description

[0030] Figure 1 The total ion current chromatogram of the dichloropropanol and isotope internal standard solutions used in Example 1 is shown below.

[0031] Figure 2 The separation chromatograms of the DB-5 column and DB-FFAP column in Example 2 are shown.

[0032] Figure 3 This is a statistical graph showing the effect of equilibrium temperature on the peak area response of dichloropropanol in Example 3.

[0033] Figure 4 This is a statistical graph showing the effect of equilibration time on the peak area response of dichloropropanol in Example 3.

[0034] Figure 5 This is a statistical graph showing the effect of the amount of matrix modifier added on the peak area response value of dichloropropanol in Example 4.

[0035] Figure 6 This is a statistical graph showing the effect of the amount of solid-phase adsorbent PSA added on the peak area response value of dichloropropanol in Example 4.

[0036] Figure 7 This is a statistical graph showing the effect of the amount of reduced graphene oxide added on the chromatographic peak area response value of dichloropropanol in Example 4.

[0037] Figure 8 This is a statistical graph showing the effect of the ratio of solid-phase adsorbent PSA to lipophilic synthetic lithium montmorillonite on the peak area response value of dichloropropanol in Example 4.

[0038] Figure 9 This is a gas chromatogram obtained from the determination method in Example 7. Detailed Implementation

[0039] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0040] The reagents and instruments used in the following examples are as follows:

[0041] 1. Standard solution reagent

[0042] 1,3-Dichloro-2-propanol (1,3-DCP, CAS No. 96-23-1); 2,3-Dichloro-1-propanol (2,3-DCP, CAS No. 616-23-9); 1,3-Dichloro-2-propanol-D5 (1,3-DCP-D5, CAS No. 1173020-20-6); 2,3-Dichloro-1-propanol-D5 (2,3-DCP-D5, CAS No. 1189730-34-4), purity ≥99%; methanol (chromatographic grade); sodium sulfate (analytical grade, ignited in a muffle furnace at 400℃ for 4h, cooled to room temperature in a desiccator, and stored in a ground glass bottle); reduced graphene oxide (monolayer, sheet diameter 1-5μm);

[0043] Lipophilic synthetic lithium montmorillonite was purchased from Shanghai Anpu Technology Co., Ltd. (10-20 mesh, calcined in a muffle furnace at 400℃ for 4 hours, cooled to room temperature in a desiccator, and then transferred to a ground glass bottle for storage); quartz sand (20-50 mesh SiO2 powder);

[0044] Matrix modifier (measure 500 mL of experimental water, add 100 g of sodium sulfate, dissolve and mix well, store at 4 °C, shelf life 6 months).

[0045] 2. Preparation of standard samples

[0046] Dichloropropanol stock solution 2000 μg / mL: Weigh 0.02 g (1,3-DCP, 2,3-DCP) into 10 mL volumetric flasks, dissolve in methanol, dilute to the mark, mix well, and store at -18 °C.

[0047] Dichloropropanol working solution 100 μg / mL: Transfer 500 μL of dichloropropanol stock solution into a 10 mL volumetric flask, dilute to the mark with methanol, mix well, and store at -18℃.

[0048] Isotope internal standard stock solution 2000 μg / mL: Weigh 0.02 g (1,3-DCP-D5, 2,3-DCP-D5) into 10 mL volumetric flasks, dissolve in methanol, dilute to the mark, mix well, and store at -18℃.

[0049] Isotope internal standard working solution 100 μg / mL: Transfer 500 μL of isotope internal standard stock solution into a 10 mL volumetric flask, dilute to the mark with methanol, mix well, and store at -18℃.

[0050] 3. Preparation of solid waste samples to be tested

[0051] Solid waste sample bottle to be tested: Use an iron shovel or stainless steel spoon to collect the solid waste sample to be tested into the brown glass sample bottle, and fill it as full as possible. Remove the sample adhering to the threads and outer surface of the sample bottle, seal the sample bottle, and store it in a cool, dark place (≤4℃).

[0052] 4. Instruments

[0053] Equipment and consumables: HSS86.50 DANI automatic headspace sampler (Dani, Italy); 8890-5977B gas chromatograph-mass spectrometer (Agilent Technologies, USA); 22mL headspace vials (Shanghai Anpu); Vortex-Genie2 vortex mixer (SI, USA); L550 benchtop low-speed centrifuge (Hunan Xiangyi).

[0054] Example 1

[0055] This embodiment provides a method for determining dichloropropanol in solid waste, comprising the following steps:

[0056] (1) Take out the sample bottle of solid waste to be tested in the laboratory. After it returns to room temperature, place the solid waste sample on a dry and clean enamel tray, remove impurities, and grind the sample quickly or crush it so that the sample particle size can pass through a 1 mm sieve and be fully homogenized; for solid waste samples that are not easy to grind, use methods such as cutting or tearing to reduce the sample volume and obtain the solid waste sample to be tested.

[0057] Weigh 2g (accurate to 0.01g) of the solid waste sample to be tested into a headspace vial. Quickly add 10.0mL of matrix modifier, 5.0μL of isotope internal standard solution, 10mg of PSA (N-propylethylenediamine) solid adsorbent, 10mg of reduced graphene oxide, and 150mg of lipophilic synthetic lithium montmorillonite to the headspace vial (22mL). Seal immediately. Mix the sample in a vortex mixer for 30s, and then sonicate in a water bath for 30min (protect from light and control the temperature below 30℃ during sonication). Remove the headspace vial and place it in a centrifuge. Centrifuge at 3000rpm for 5min to obtain the sample to be tested.

[0058] (2) Place the sample to be tested obtained in step (1) into an automatic headspace sampler. After equilibration in the automatic headspace sampler, detect the dichloropropanol in the gas phase by gas chromatography and mass spectrometry.

[0059] Automatic headspace sampler conditions: equilibrium temperature 90℃; equilibrium time 30 min; sampling needle temperature 105℃; transfer line temperature 110℃; pressure equilibrium time 1 min; injection time 0.2 min; needle withdrawal time 0.4 min;

[0060] Gas chromatography conditions: Injector temperature: 250℃; Split ratio: 5:1; Column: DB-FFAP (30m×0.25mm×0.25μm); Column flow rate: 1.0mL / min; Temperature program: 60℃ for 2 min, increase to 160℃ at a rate of 8℃ / min, hold for 2 min, increase to 240℃ at a rate of 20℃ / min, hold for 0 min;

[0061] Mass spectrometry conditions: transfer line temperature: 260℃; ion source temperature: 230℃; MS quadrupole: 150℃; mass spectrometry bombardment electron energy: 70eV.

[0062] Selecting ion scanning mode (SIM), without adding the solid waste sample to be tested, the retention times, quantitative ions, and qualitative ions of dichloropropanol and internal standard are shown in Table 1. The total ion chromatograms of dichloropropanol and isotopic internal standard are shown in [Table 1]. Figure 2 .

[0063] Table 1 Retention time, quantitative ions, and qualitative ions of dichloropropanol contaminants and isotopic internal standards.

[0064]

[0065]

[0066] Example 2

[0067] Optimization of chromatographic conditions

[0068] This example compares the separation of two dichloropropanol compounds using a weakly polar DB-5 column (30m × 0.25mm × 0.25μm) and a strongly polar DB-FFAP column (30m × 0.25mm × 0.25μm). The results show that the target analyte exhibits peak tailing on the DB-5 column, while the DB-FFAP column produces sharper peaks and better separation. The separation chromatograms of the two columns are shown below. Figure 2 As shown.

[0069] Example 3

[0070] Automated headspace sampler condition optimization

[0071] 1. Optimization of equilibrium temperature

[0072] In this embodiment, experiments were conducted on a blank spiked sample (without the solid waste sample to be tested) with a spiked concentration of 100 μg / kg under heating equilibrium temperatures of 60℃, 70℃, 80℃, and 90℃, with other parameters set as in Example 1. The response of equilibrium temperature to the chromatographic peak area of ​​dichloropropanol was compared, and the results are as follows. Figure 3 As shown, experiments revealed that the peak area of ​​the target compound was larger at 90℃ than at other temperatures, which may be because higher temperatures facilitate the extraction of the target compound. Considering the boiling point of water, and to prevent excessive water from entering the instrument system, the headspace sampler equilibrium temperature in this invention is set to 90℃.

[0073] 2. Optimization of balancing time

[0074] In this embodiment, under heating equilibrium times of 20 min, 30 min, 40 min, and 50 min, and with other parameters set as in Example 1, experiments were conducted on a blank spiked sample (without the solid waste sample to be tested) with a spike dosage of 100 μg / kg to compare the response of equilibrium time to the peak area of ​​dichloropropanol. The results are as follows: Figure 4 As shown, the response area gradually increases with the increase of the equilibration time. When the equilibration time reaches 30 min, the peak area response value does not change significantly. Considering both energy saving and improving sample analysis efficiency, the optimal equilibration time for the automatic headspace sampler is 30 min.

[0075] Example 4

[0076] Optimization of pretreatment conditions for solid waste to be tested

[0077] 1. Selection of matrix modifier

[0078] In this embodiment, to investigate the effect of matrix modifiers containing salts of different ionic strengths on the peak area response of dichloropropanol, experiments were conducted under the following conditions: no salt added, 10 mL saturated sodium chloride, 10 mL saturated sodium carbonate, and 10 mL saturated sodium sulfate. Other parameters were set according to Example 1. Experiments were performed on a blank spiked sample (without the solid waste sample to be tested) with a spiked amount of 100 μg / kg. The results are as follows: Figure 5 As shown, Figure 5 The results showed that the addition of inorganic salts significantly improved the peak area response value. The peak area response value was lowest with 10 mL of saturated sodium carbonate, which is speculated to be due to the alkalinity of the saturated sodium carbonate solution, which may have damaged the target analyte. The peak area response value was highest with 10 mL of saturated sodium sulfate. Therefore, saturated sodium sulfate solution was selected as the matrix modifier.

[0079] 2. Optimization of the dosage of solid-phase adsorbent PSA

[0080] In this embodiment, to investigate the effect of different amounts of solid-phase adsorbent added on the peak area response of dichloropropanol, 5 mg PSA, 10 mg PSA, 15 mg PSA, and 20 mg PSA were added, respectively. Other parameters and conditions were set as in Example 1. The experiment was conducted on a blank spiked sample (without the solid waste sample to be tested) with a spiked amount of 100 μg / kg. The results are as follows: Figure 6 As shown, the addition of solid-phase adsorbent can significantly remove impurities and improve peak area response value. The peak area response value is the largest when 10 mg PSA is added, and then shows a downward trend. It is speculated that as the amount of solid-phase adsorbent increases, it may adsorb the target analyte while adsorbing impurities. Therefore, 10 mg PSA is selected as the optimal amount of solid adsorbent to be added.

[0081] 3. Optimization of the amount of reduced graphene oxide added

[0082] In this embodiment, to investigate the effect of different amounts of reduced graphene oxide added on the peak area response of dichloropropanol, 5 mg, 10 mg, 15 mg, and 20 mg of reduced graphene oxide were added, respectively. Other parameters and conditions were set as in Example 1. The experiment was conducted on a blank spiked sample (without the solid waste sample to be tested) with a spiked amount of 100 μg / kg. The results are as follows. Figure 7 As shown, the addition of reduced graphene oxide can significantly remove impurities and improve the peak area response value. The peak area response value is the largest when 10 mg of reduced graphene oxide is added, and then shows a downward trend. Therefore, 10 mg of reduced graphene oxide is selected as the optimal amount of adsorbent to be added.

[0083] 4. Optimization of the addition ratio of lipophilic synthetic lithium montmorillonite

[0084] In this embodiment, to investigate the effect of different ratios of PSA and lipophilic synthetic lithium montmorillonite on the peak area response of dichloropropanol, lipophilic synthetic lithium montmorillonite was added at ratios of 1:5, 1:10, 1:15, and 1:20 (i.e., based on a PSA addition of 10 mg, the actual lipophilic synthetic lithium montmorillonite addition amounts were 50 mg, 100 mg, 150 mg, and 200 mg, respectively). Other parameters were set as in Example 1. The experiment was conducted on a blank spiked sample (i.e., without the solid waste sample to be tested) with a spiked amount of 100 μg / kg. The results are as follows. Figure 8 As shown, the peak area response value is the largest when the addition ratio is 1:15 (150 mg of lipophilic synthetic lithium montmorillonite), and the peak area response value remains stable at the same ratio. Considering the headspace solution volume, the optimal addition ratio of PSA to lipophilic synthetic lithium montmorillonite is 1:15.

[0085] Example 5

[0086] Calibration curve and method detection limit

[0087] Five headspace vials were taken, and 2g of quartz sand and 10mL of matrix modifier were added sequentially. Then, a certain amount (0.5μL, 1.0μL, 2.0μL, 5.0μL, and 10.0μL) of dichloropropanol standard working solution was added to each vial to achieve concentrations of 5, 10, 20, 50, and 100 μg / L, respectively. Next, 5.0μL of internal standard working solution was added to each vial to achieve an internal standard concentration of 50 μg / L. The vials were immediately sealed, and the samples were injected sequentially from low to high concentrations according to the instrument analysis conditions described in Example 1. A calibration curve was established with the dichloropropanol concentration as the x-axis and the product of the ratio of the dichloropropanol to the internal standard quantitative ion response value and the internal standard concentration as the x-axis. The results are shown in Table 2. The method detection limit was determined according to method A.1.1b) of the "Technical Guidelines for the Formulation and Revision of Environmental Monitoring Analytical Methods Standards" (HJ 168-2020). Seven low-concentration samples (25 μg / kg) were prepared and tested. The standard deviation (s) of the results of the seven parallel samples was calculated. The detection limit was calculated according to the 3.143s method. The lower limit of quantitation was calculated by multiplying the detection limit by 4. The performance parameters are shown in Table 2.

[0088] Table 2 Performance Parameters

[0089]

[0090] Example 6

[0091] Precision and accuracy tests

[0092] In this embodiment, samples of typical solid waste types, ash and biochemical sludge, were spiked using a sample spiking method. Three concentration levels were set at 50 μg / kg, 100 μg / kg, and 250 μg / kg. The determination was performed according to the method and steps in Example 1, and six parallel experiments were repeated for each. The recovery rate and relative standard deviation were calculated, and the results are shown in Table 3.

[0093] Table 3. Spiked recoveries and relative standard deviations of dichloropropanol (n=6)

[0094]

[0095] Table 3 shows that the relative standard deviations (RSDs) for the three concentration levels of the biochemical sludge samples were 1.8%–6.1%; the RSDs for the three concentration levels of the industrial ash samples were 2.8%–6.8%. All RSDs were below 10%, indicating good precision of the method described in this invention. The spiked recoveries for the three concentration levels of the biochemical sludge samples were 86%–102%; the spiked recoveries for the three concentration levels of the industrial ash samples were 89%–104%, demonstrating that the method of this invention has good accuracy and precision, meeting the analytical requirements for solid waste.

[0096] Example 7

[0097] The method obtained in the examples was applied to the analysis of solid waste samples from a food company in Changsha City. The results are shown in Table 4, and the obtained chromatograms are as follows. Figure 9 As shown.

[0098] Table 4. Measurement results of actual samples

[0099]

[0100] As shown in Table 4, dichloropropanol was detected in all six samples at different concentrations, ranging from 16.4 to 63.6 μg / kg. However, none of the concentrations exceeded the standard limit requirements (total content of one or more carcinogenic substances ≥ 0.1%) specified in GB 5085.6-2007 "Identification Standard for Hazardous Waste - Identification of Toxic Substance Content").

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for determining dichloropropanol in solid waste, characterized in that, Includes the following steps: (1) Add the solid waste to be tested, matrix modifier, isotope internal standard solution, N-propylethylenediamine solid adsorbent, reduced graphene oxide and lipophilic synthetic lithium montmorillonite into a headspace vial, shake, sonicate, and centrifuge to obtain the sample to be tested; (2) Place the sample to be tested obtained in step (1) into an automatic headspace sampler. After equilibration in the automatic headspace sampler, detect the dichloropropanol in the gas phase by gas chromatography and mass spectrometry. In step (1), the matrix modifier is a saturated sodium sulfate solution; In step (1), the isotope internal standard solution includes 1,3-dichloro-2-propanol-D5 solution and 2,3-dichloro-1-propanol-D5 solution, and the concentrations of the 1,3-dichloro-2-propanol-D5 solution and the 2,3-dichloro-1-propanol-D5 solution are 5 μg / mL to 100 μg / mL; In step (1), the mass ratio of the N-propylethylenediamine solid adsorbent, the reduced graphene oxide, and the lipophilic synthetic lithium montmorillonite is 1:1:

15. In step (1), the mass of the solid waste to be tested is 2g, and the mass of N-propylethylenediamine is 10mg; The dichloropropanol includes 1,3-dichloro-2-propanol and 2,3-dichloro-1-propanol; In step (2), the chromatographic column is DB-FFAP 30 m × 0.25 mm × 0.25 μm; the temperature program is 60℃ for 2 min, then increased to 160℃ at a rate of 8℃ / min and held for 2 min.

2. The method for determining dichloropropanol in solid waste according to claim 1, characterized in that, In step (1), the mass-to-volume ratio of the solid waste to be tested to the matrix modifier is 2:10, g / mL.

3. The method for determining dichloropropanol in solid waste according to claim 1, characterized in that... In step (2), the equilibrium temperature is 90°C and the time is not less than 30 minutes.

4. The method for determining dichloropropanol in solid waste according to claim 1, characterized in that, In step (2), the conditions of the automatic headspace sampler are: equilibrium temperature 90℃; equilibrium time 30min; sampling needle temperature 105℃; transmission line temperature 110℃; pressure equilibrium time 1min; injection time 0.2min; needle withdrawal time 0.4min.

5. The method for determining dichloropropanol in solid waste according to claim 1, characterized in that, In step (2), the gas chromatography conditions are: injection port temperature: 250°C; split ratio: 5:1; column flow rate: 1.0 mL / min; And / or, in step (2), the conditions for the mass spectrometer are: transfer line temperature: 260℃; ion source temperature: 230℃; MS quadrupole: 150℃; mass spectrometer bombardment electron energy: 70 eV.

6. The method for determining dichloropropanol in solid waste according to claim 1, characterized in that, The detection limits for 1,3-dichloro-2-propanol and 2,3-dichloro-1-propanol in the method for determining dichloropropanol in solid waste are 1.4 μg / kg and 2.7 μg / kg, respectively.

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