Method for detecting various organophosphates in water body

Abstract

The invention discloses a method for detecting various organophosphorus esters in a water body, belongs to the technical field of organophosphorus ester detection, and particularly discloses a method for extracting various organophosphorus esters in water and a detection method for analyzing various organophosphorus esters in a full scanning mode based on ultra-high performance liquid chromatography electrostatic field orbitrap mass spectrometry. According to the method provided by the invention, 12 typical organophosphorus esters in the water body can be effectively separated, accurately qualitatively quantified and accurately quantified, the ion mass-to-charge ratio deviation is within 5ppm, and a good linear relation and a correlation coefficient gt are shown when the concentration is in a range of 2.5-200mu g / L; the detection limit ranges from 0.140 ng / mL to 0.921 ng / mL, and the quantification limit ranges from 0.280 ng / mL to 1.84 ng / mL. The matrix adding standard recovery range is 74.0%-117.1%, the relative standard deviation between parallel samples is lower than 10%, and the method has good reproducibility and low detection limit.

Description

Technical Field

[0001] The present invention relates to the technical field of organophosphate detection, and more specifically, to a method for detecting multiple organophosphates in water bodies. Background Art

[0002] Organophosphate esters (OPEs) are a class of compounds formed by substituting hydrogen on the hydroxyl group of phosphoric acid molecules with alkyl or aryl groups. According to the substituents, they are mainly divided into alkyl-OPEs, chloro-OPEs, and aryl-OPEs. Due to their excellent flame retardant and plasticizing properties, OPEs have become the main substitutes for brominated flame retardants and are widely used in products such as plastics, furniture, electronic products, textiles, building materials, and lubricants. Their production and usage have been increasing year by year. In subsequent use, it was found that OPEs still have similar persistence and serious health risks. The metabolites of these pollutants can damage the function of pancreatic islet β cells and worsen the development of diabetes after entering the human body. Tris(2-chloroethyl) phosphate (TCEP) and tris(1,3-dichloroisopropyl) phosphate (TDCPP) have been classified as Group 2 carcinogens. Animal experiments have proven that tributyl phosphate (TnBP) and tris(2-butoxyethyl) phosphate (TBEP) have neurotoxicity and reproductive and developmental toxicity. Therefore, OPEs are called regrettable substitutes and have become new pollutants that have attracted much attention from the international community.

[0003] Since OPEs are usually added to products physically rather than through chemical bonding, and do not form stable chemical bonds with materials, they are easily released into the environment through abrasion, volatilization, exudation, etc. during the manufacturing, use, and recycling processes of these products. Different substituents determine that the physicochemical properties of each monomer compound vary greatly, and their environmental behaviors are also significantly different. The volatile OPEs in materials diffuse in the atmosphere in the form of aerosols and enter water bodies or soils through dry / wet deposition or gas-liquid / gas-solid exchange. Chlorinated OPEs with high water solubility are still difficult to effectively remove after passing through traditional municipal sewage treatment processes and will eventually be discharged into natural water bodies.

[0004] Rivers, as important freshwater resources, are the water bodies most closely related to human life and have continuity in spatial scale, enabling pollutants to spread between different environmental media. Comprehensively understanding the pollution concentration levels of OPEs in water bodies such as rivers is crucial for protecting the aquatic environment. Based on ultra-high performance liquid chromatography-electrostatic field orbitrap high-resolution mass spectrometry technology, the present invention optimizes the extraction and purification extraction column and related parameters of the mobile phase for OPEs in water samples, and establishes a method for detecting multiple organophosphate compounds in water bodies that is efficient, accurate, and time-consuming. Summary of the Invention

[0005] The object of the present invention is to provide a method for detecting multiple organophosphates in water bodies, simultaneously detecting multiple organophosphate compounds in polluted water bodies, and the correlation coefficient R of the standard working curve 2 is greater than 0.995.

[0006] The above technical object of the present invention is achieved by the following technical solutions: A method for detecting multiple organophosphates in water bodies, comprising the following steps:

[0007] S1. Add a small amount of methanol to the water sample to be treated, filter to remove impurities, and then add a recovery indicator mixture;

[0008] S2. Extraction and separation: Activate the solid-phase extraction column with an organic solvent. The water sample in step (1) is enriched on the SPE small column through a large-flow sampling tube at a flow rate of 6 mL / min, and an elution solvent is used for elution operation. The eluate is collected. After the eluate is gently blown to near dryness with nitrogen, it is re-dissolved with an organic solvent for analysis on the machine;

[0009] S3. Prepare a standard curve: Prepare organic phosphate standard solutions with different concentration gradients containing a recovery indicator;

[0010] S4. Sample detection: Qualitative and quantitative analysis of organophosphate compounds is carried out by ultra-high performance liquid chromatography - electrostatic field orbitrap mass spectrometry;

[0011] In step S4, an ACQUITY UPLC BEH C18 chromatographic column is selected for the liquid chromatography column, and the column temperature is 40 °C; Mobile phase: water is phase A, and methanol is phase B; The flow rate is 0.25 mL / min, and the injection volume is 1 μL; The initial mobile phase is 90% phase A and 10% phase B, which is maintained for 1 min. Phase B is gradually adjusted to 70% within 1 - 3 min, and phase B is adjusted to 100% within 3 - 5 min, which is maintained for 10 min. Phase B is reduced to 10% within 0.1 min and maintained for 2.9 min;

[0012] Mass spectrometry conditions: Electrospray ionization source ESI + Combined with the Full mass mode, the spray voltage is 3.5 kV; The capillary temperature is 320 °C; The auxiliary gas heater temperature is 300 °C; The sheath gas flow rate is 35 arb; The auxiliary gas flow rate is 10 arb; The S-lens RF level is 50 V; The detector is Orbitrap; The mass spectrometry resolution is 70000 FWHM; The scanning range is 50 - 550 m / z; The maximum injection time is 200 ms; The MS automatic gain control target is 2.0×10 5 ; The monitored ion is [M + H] + .

[0013] The present invention is further configured such that: the organophosphate ester includes one or more of triethyl phosphate (TEP), tripropyl phosphate (TPrP), tributyl phosphate (TnBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloroisopropyl) phosphate (TDCPP), tris(2-butoxyethyl) phosphate (TBEP), triphenyl phosphate (TPhP), triisooctyl phosphate (TEHP), tricresyl phosphate (TCP), 2-ethylhexyl diphenyl phosphate (EHDPP), and triisopropyl phosphate (TiPP).

[0014] The present invention is further configured such that: in step S1, the dosage ratio of methanol to the water sample to be measured is 25 mL:500 mL, and the water sample to be treated is filtered using a Whatman GF / F 0.7 μm glass fiber filter membrane.

[0015] The present invention is further configured such that: in step S1, the added recovery indicator mixture is 1 ng, and the recovery indicator mixture includes D 12 -TCEP, D 27 -TnBP, and D 15 -TPhP.

[0016] The present invention is further configured such that: in step S2, the solid-phase extraction column is Oasis HLB, 200 mg, 6 mL.

[0017] The present invention is further configured such that: in step S2, the organic solvents for activating the extraction column are ethyl acetate, methanol, and methanol aqueous solution in sequence, the volumes of the ethyl acetate, methanol, and methanol aqueous solution are 3 mL:3 mL:3 mL respectively, and the volume ratio of methanol to water in the methanol aqueous solution is 1:99.

[0018] The present invention is further configured such that: in step S2, the elution solvent is 9 mL of ethyl acetate and 4 mL of methanol; the reconstitution organic solvent after nitrogen blowing is methanol, and the added amount is 200 μL.

[0019] The present invention is further configured such that: in step S3, the concentration gradients of the compounds in the standard curve solution are 2.5 ng / mL, 5 ng / mL, 10 ng / mL, 20 ng / mL, 25 ng / mL, 50 ng / mL, 100 ng / mL, and 200 ng / mL, and the added amounts of the recovery indicators are the same, all being 5 ng.

[0020] In summary, the present invention has the following beneficial effects:

[0021] 1. The present invention enriches, purifies and separates various organophosphate compounds in water samples based on solid-phase extraction. The pretreatment process takes a relatively short time, is simple and easy to operate; moreover, the amount of organic solvent used is small, and the environmental pollution is relatively light; plastic products are not used during the experiment, reducing background pollution.

[0022] 2. The present invention successfully establishes a qualitative and quantitative analysis method for 12 typical organophosphate compounds and 3 recovery indicators by using ultra-high performance liquid chromatography coupled with electrostatic field orbitrap mass spectrometry technology. The water sample extraction samples are detected, and the detection limit is relatively low, and the sensitivity and reproducibility are high, which is suitable for the detection and analysis of trace organophosphate compounds in media such as water bodies.

[0023] 3. Tricresyl phosphate (TCP) and 2-ethylhexyl diphenyl phosphate (EHDPP) have strong lipophilicity, poor solubility in pure water, and are easily adsorbed on the sample bottle and filter membrane, resulting in losses. In the present invention, methanol is added and mixed evenly before filtration, which can improve the solubility of the compounds, and the spike recovery rate and detection results are more accurate. Description of the Drawings

[0024] Figure 1 It is the extracted ion chromatogram of 12 target compounds and 3 recovery indicators in the embodiment of the present invention;

[0025] Figure 2 It is the response intensity of various organophosphate compounds under different mobile phases and different standard curve solvents in the embodiment of the present invention. Detailed Embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] The physicochemical property parameters of typical organophosphate compounds are listed in Table 1.

[0028] Table 1 Physicochemical Properties of Typical Organophosphates in Water

[0029]

[0030]

[0031] Example 1: The present invention provides a pretreatment method and a detection method for extracting various organophosphates in water, including the following steps:

[0032] 1. Main Instruments and Reagent Materials

[0033] 1.1 Instruments

[0034] Ultra-high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometer (UHPLC-Q-Orbitrap HRMS, Thermo Fisher Scientific, USA), RDK JRES-02B laboratory ultrapure water machine of Chongqing Runde Kangjian Water Treatment Equipment Co., Ltd., FBZ2002-UP-P ultrapure water machine of Qingdao Fulham Co., VORTEX 3 vortex mixer (Germany), Hamilton glass micro syringe (USA).

[0035] 1.2 Reagents and Consumables

[0036] Triethyl phosphate (TEP), tripropyl phosphate (TPrP), tributyl phosphate (TnBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloroisopropyl) phosphate (TDCPP), tris(2-butoxyethyl) phosphate (TBEP), triphenyl phosphate (TPhP), triisooctyl phosphate (TEHP), tricresyl phosphate (TCP), 2-ethylhexyl diphenyl phosphate (EHDPP), triisopropyl phosphate (TiPP) standards and D 27 -TnBP standards were all purchased from AccuStandard Inc. (New Haven, CT, USA); D 12 -TCEP was purchased from MedChemExpress (USA); D 15 -TPhP was purchased from Shanghai Zhenzhun Biotechnology Co., Ltd. (zzstandard) in China; HPLC grade methanol was purchased from Fisher Chemical (USA), HPLC grade ethyl acetate was purchased from Anaqua Chemicals Supply (USA); Wat HLB solid phase extraction column (200mg, 6mL) was purchased from Waters company (Milford, MA, USA), CNW BOND HC-C18 solid phase extraction column (500mg, 6mL) and CNW poly-sery HLB Pro solid phase extraction column (200mg, 6mL) were purchased from Shanghai Anpu. GF / F glass fiber filter membrane (diameter 47mm, pore size 0.7μm) was purchased from Whatman (UK).

[0037] 2. Determination of Standard Working Curve

[0038] Preparation of the standard working curve: Take the mixed standard solution of organophosphate compounds and add methanol solvent for stepwise dilution to obtain 8 standard working curves at different concentration levels: 2.5 ng / mL, 5 ng / mL, 10 ng / mL, 20 ng / mL, 25 ng / mL, 50 ng / mL, 100 ng / mL, and 200 ng / mL. The recovery indicator D 12 -TCEP, D 27 -TnBP, and D 15 -TPhP are added in the same amount, which is 5 ng. Quantitative analysis is carried out by the internal standard method. Taking the concentration of the target compound standard solution as the abscissa and the chromatographic peak areas of the target compound and the corresponding recovery indicator as the ordinate, a standard curve is established, and the content of organophosphates in the subsequent detected samples is obtained according to the standard curve.

[0039] 3. Pretreatment process

[0040] Accurately measure 500 mL of ultrapure water, add 1 ng of recovery indicator, including D 12 -TCEP, D 27 -TnBP, and D 15 -TPhP, add 25 mL of methanol, mix well, and filter the water sample with a Whatman GF / F (diameter 47 mm, pore size 0.7 μm) filter membrane.

[0041] Activated the Wat HLB solid-phase extraction column with 3 mL of ethyl acetate, 3 mL of methanol, and 3 mL of methanol / water (1:99, v / v) in sequence, and enrich the water sample through a large-flow sampling tube, controlling the flow rate at 6 ml / min.

[0042] After the loading is completed, wash the small column with 5 mL of methanol / water (1:99, v / v), and after completion, completely dry the solid-phase extraction column to remove moisture; then elute the organophosphate compounds enriched in the solid-phase extraction column with 9 ml of ethyl acetate and 4 mL of methanol, collect the eluate; the eluate is gently blown to near dryness with nitrogen, and then fixed with 200 uL of methanol and transferred to a chromatographic vial for on-machine detection.

[0043] Since organophosphates are widely used as plasticizers, to reduce background errors, plastic products are avoided during the experiment, and glass micro-injection needles are used for all transfer processes.

[0044] 4. Analytical detection

[0045] The ACQUITY UPLC BEH C18 chromatographic column (2.1×100 mm, 1.7 μm; Waters, USA) was selected, and the column temperature was 40 °C. The mobile phase consisted of water (phase A) and methanol (phase B), with a flow rate of 0.25 mL / min and an injection volume of 1 μL. The initial mobile phase was 90% phase A and 10% phase B, which was maintained for 1 min. Phase B was gradually adjusted to 70% within 1 - 3 min, to 100% within 3 - 5 min, and maintained for 10 min. Phase B was reduced to 10% within 0.1 min and continued until 18 min, as shown in Table 2.

[0046] Table 2 Mobile phase gradient of organophosphates

[0047]

[0048]

[0049] Mass spectrometry conditions: Electrospray ionization source ESI + Combined with the Full mass mode, the spray voltage was 3.5 kV; the capillary temperature was 320 °C; the auxiliary gas heater temperature was 300 °C; the sheath gas flow rate was 35 arb; the auxiliary gas flow rate was 10 arb; the S-lens RF level was 50 V; the detector was Orbitrap; the mass spectrometry resolution was 70000 FWHM; the scanning range was 50 - 550 m / z; the maximum injection time was 200 ms; the MS automatic gain control target was 2.0×10 5 ; The monitored ion was [M + H] + ion; the mass deviation was 5 ppm. The content of organophosphate compounds was quantitatively detected by ultra-high performance liquid chromatography - electrostatic field orbitrap high-resolution mass spectrometry, and the mass spectrometry information is shown in Table 3.

[0050] Table 3 Mass spectrometry parameters of target compounds

[0051] Target compound Retention time (min) Exact mass number (m / z) TEP 5.83 183.07807 TCEP 6.09 284.96115 TiPP 6.58 225.12502 TPrP 6.68 225.12502 TCPP 6.65 327.00811 TDCPP 6.95 430.88824 TPhP 6.99 327.07807 TnBP 7.18 267.17197 TBEP 7.28 399.25062 TCP 7.45 369.12502 EHDPP 7.61 363.17197 TEHP 9.58 435.35977 <![CDATA[D 12 -TCEP]]> 6.08 297.03648 <![CDATA[D 27 -TnBP]]> 7.16 294.34144 <![CDATA[D 15 -TPhP]]> 6.96 342.17222

[0052] 5. Linear equations, correlation coefficients R 2 of organophosphate compounds, detection limits, and quantification limits

[0053] Eight standard working curves with different concentration gradients were set. The detection limit LOD of the instrument was calculated as 3 times the standard deviation of the response values of the lowest concentration point injected continuously 7 times, and 2 times the LOD value was used as the quantification limit LOQ. The information of the standard working curves is shown in Table 4. Twelve organophosphate compounds had good linear relationships in the range of 2.5 - 200 ng / mL, and R 2 was greater than 0.995. The LOD range was 0.140 - 0.921 ng / mL, and the LOQ range was 0.280 - 1.84.

[0054] Table 4 Standard Curve

[0055]

[0056] Example 2: Selection of Different Mobile Phase Ratios and Different Standard Curve Solvents

[0057] This example focused on studying the influence of different mobile phase combinations and different standard curve solvents on the detection response of organophosphate compounds. The specific mobile phase settings are as follows: methanol - ultrapure water, methanol - ultrapure aqueous solution containing 5 mmol / L ammonium acetate, methanol - ultrapure aqueous solution containing 2 mmol / L ammonium acetate, methanol - ultrapure aqueous solution containing 0.0025% (v / v) formic acid. The specific standard curve solvent settings are as follows: methanol, methanol containing 50% ultrapure water.

[0058] The response intensities of various organophosphate compounds under different mobile phases and different standard curve solvents are shown in Table 5 and the corresponding Figure 2 .

[0059] Table 5 Response Values of Various Organophosphates under Different Mobile Phase Compositions and Different Standard Curve Solvents

[0060]

[0061] Combined with Figure 2 and the data in Table 5, the results show that: for samples with the same concentration, the mobile phase system provided by the present invention can generate the maximum signal intensity and signal-to-noise ratio. Followed by methanol - ultrapure aqueous solution containing 0.0025% (v / v) formic acid and methanol - ultrapure aqueous solution containing 2 mmol / L ammonium acetate, while the response value of methanol - ultrapure aqueous solution containing 5 mmol / L ammonium acetate is relatively low. For samples with the same concentration and the same mobile phase system, the standard curve of methanol solvent containing 50% ultrapure water has a slightly lower or similar response value compared to the standard curve of pure methanol solvent.

[0062] In summary, the present invention finally selects methanol - ultrapure water as the mobile phase and methanol as the standard curve solvent to analyze organophosphate compounds in water.

[0063] Example 3: Selection of Different Solid Phase Extraction Columns

[0064] Detection was carried out according to the methods of Example 1 and Example 2 to study the influence of different types of solid phase extraction cartridges on the spiked recovery rate of organophosphates in the pretreatment. The types of solid phase extraction columns include CNW BOND HC - C18 SPE column (500 mg, 6 mL, Anpu), CNW poly - sery HLB Pro SPE column (200 mg, 6 mL, Anpu) and Wat HLB SPE cartridges (200 mg 6 mL, Waters). The spike recovery rates and background blank results of organophosphates detected by different solid-phase extraction cartridges are shown in Table 6 below.

[0065] Table 6 Spike recovery rates (n = 3) and background blank values of organophosphates under different solid-phase extraction cartridges

[0066]

[0067] As can be seen from Table 6, the influence of different extraction cartridges on the spike recovery rates of organophosphates is relatively significant. After enriching and purifying the water samples with the HLB solid-phase extraction cartridge, the recovery rates of 12 typical organophosphates and 3 recovery rate indicators all fall between 74% - 118%, and the background blank value is relatively low, indicating that the method of the present invention has good detection effects on the 12 target compounds and can meet the detection requirements. HLB solid-phase extraction cartridges were used to enrich and purify water samples. The recovery rates of 12 typical organophosphates and 3 recovery rate indicators all fell between 74% - 118%. The background blank value was relatively low, indicating that the method of the present invention had good detection effects on the 12 target compounds and could meet the detection requirements.

[0068] Example 4: Detection of actual samples

[0069] Water samples were collected during the flooding period (winter) from Changshou, Chongqing to Zigui, Hubei in the Three Gorges Reservoir area. Using the above-developed detection method, the determination results of organophosphates in the actual water samples at 16 sampling points are shown in Table 7. Among the 12 target compounds, 10 organophosphates were detected. The detection rates of TEP, TCEP, TCPP, TPhP, and TnBP were 100%, and they were detected at all sampling points. The detection rates of TiPP and TPrP were higher than 50%, and they were present in more than half of the samples. TnBP was the main component, with a median concentration of 69.4 ng / L and a concentration range between 54.2 - 91.1 ng / L.

[0070] Table 7 Determination results of organophosphate compounds in the Yangtze River water samples (ND: not detected)

[0071] Target compound Detection rate (%) Concentration range ng / L Average value ng / L Median value ng / L TEP 100％ 1.44-3.68 2.21 2.06 TCEP 100％ 2.75-4.21 3.41 3.35 TiPP 56.3％ ND - 0.04 0.01 0.01 TCPP 100％ 2.82-381 75.5 6.58 TPrP 56.3％ ND - 0.16 0.09 0.15 TDCPP 0.0％ ND ND ND TPhP 100％ 0.29-0.65 0.41 0.40 TnBP 100％ 54.2-91.1 69.9 69.4 TBEP 0.％ ND ND ND TCP 37.5％ ND - 0.07 0.02 ND EHDPP 18.8％ ND - 12.14 1.0 ND TEHP 0.0％ ND ND ND total 100％ 64.0-448 153 87.9

[0072] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting multiple organophosphates in water, characterized in that: The steps include: S1. Water sample pretreatment: Add a small amount of methanol to the water sample to be treated, filter to remove impurities, and then add the recovery indicator mixed solution; S2. Extraction and separation: Activate the solid phase extraction column with an organic solvent, enrich the water sample in step (1) in the SPE column at a flow rate of 6 mL / min through a large flow sampling tube, use an elution solvent for elution, collect the eluate, blow the eluate to near dryness with gentle nitrogen gas, and then use an organic solvent to redissolve it for loading; S3. Prepare a standard curve: prepare organophosphate standard solutions containing recovery rate indicators at different concentration gradients; S4. Sample testing: Ultra-high performance liquid chromatography-orbitrap mass spectrometry was used to qualitatively and quantitatively analyze organophosphate compounds; The liquid chromatography column selected was an ACQUITY UPLC BEH C18 column, with a column temperature of 40°C; the mobile phase was water as phase A and methanol as phase B; the flow rate was 0.25 mL / min, and the injection volume was 1 μL; the initial mobile phase was 90% phase A and 10% phase B, which was maintained for 1 min, and the phase B was gradually adjusted to 70% within 1-3 min, and the phase B was adjusted to 100% within 3-5 min, and maintained for 10 min, and the phase B was reduced to 10% within 0.1 min and maintained for 2.9 min; Mass spectrometry conditions: electrospray ionization source ESI + Combined with Full mass mode, the spray voltage was 3.5 kV; the capillary temperature was 320 °C; the auxiliary gas heater temperature was 300 °C; the sheath gas flow rate was 35 arb; the auxiliary gas flow rate was 10 arb; the S-lens RF level was 50 V; the detector was Orbitrap; the mass spectrometer resolution was 70000 FWHM; the scan range was 50-550 m / z; the maximum injection time was 200 ms; and the MS automatic gain control target was 2.0 × 10 5 ; The monitored ions are [M+H] + .

2. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: The organic phosphate includes one or more of triethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(2-chloroethyl) phosphate, tri(1-chloro-2-propyl) phosphate, tri(1,3-dichloroisopropyl) phosphate, tri(2-butoxyethyl) phosphate, triphenyl phosphate, triisooctyl phosphate, tricresyl phosphate, 2-ethylhexyl diphenyl phosphate, and triisopropyl phosphate.

3. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: In step S1, the ratio of methanol to the water sample to be tested is 25 mL:500 mL, and the water sample to be treated is filtered using a Whatman GF / F 0.7 μm glass fiber filter membrane.

4. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: In step S1, 1 ng of the recovery indicator mixed solution is added, and the recovery indicator mixed solution includes D 12 -TCEP, D 27 -TnBP and D 15 -TPhP.

5. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: In step S2, the solid phase extraction column is Oasis HLB, 200 mg, 6 mL.

6. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: In step S2, the organic solvent for activating the extraction column is ethyl acetate, methanol and methanol aqueous solution in sequence, the volume ratio of ethyl acetate, methanol and methanol aqueous solution is 1:1:1, and the volume ratio of methanol to water in the methanol aqueous solution is 1:

99.

7. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: In step S2, the elution solvent is 9 ml of ethyl acetate and 4 mL of methanol; the organic solvent for redissolution after nitrogen blowing is methanol, and the added amount is 200 μL.

8. The method for detecting multiple organophosphates in water according to claim 1, characterized in that: In step S3, the concentration gradient of the compound in the standard curve solution is 2.5 ng / mL, 5 ng / mL, 10 ng / mL, 20 ng / mL, 25 ng / mL, 50 ng / mL, 100 ng / mL and 200 ng / mL, wherein the amount of recovery indicator added is the same, i.e., 5 ng.

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